No full-text available
To read the full-text of this research,
you can request a copy directly from the author.
The role of ecological restoration in the conservation of Whitaker's skink (Cyclodina whitakeri), a rare New Zealand lizard (Lacertilia: Scincidae)
Abstract
A programme to improve the conservation status if C. whitakeri is described. The programme involved eradication of introduced Pacific rats Rattus exulans from Korapuki Island (Mercury Islands, N-E New Zealand), documentation of the response of five species of resident lizards to release from the effects of rats, and transfer of 28 Whitaker's kinks from nearby Middle Island. Following removal of rats from Korapuki, resident lizard numbers at some coastal sites increased within 12 months, and rose 20 fold over 5yr, but measurable increases of numbers of lizards in forest areas took up to 6yr. Fifteen of the founding Whitaker's skinks on Korapuki Island have been recaptured 36 times since their release, and five Korapuki-born young have also been caught. The population is now estimated as 33. The increase in number of resident lizards and the success of the introduction of Whitaker's skinks demonstrate that predation rather than habitat deficiencies were responsible for the depleted resident lizard fauna on Korapuki Island. -from Author
... L'éradication de Carpobrotus spp. a démarré fin 2011 par un arrachage initial sur l'ensemble des stations et se poursuivra jusqu'à élimination complète de la population (Krebs et al. dans . Les opérations les plus enrichissantes nous semblent provenir de Nouvelle-Zélande, où des programmes d'éradication du Rat du Pacifique (Rattus exulans) ont été menés dans plusieurs archipels (McCallum, 1986 ;Towns, 1994 ;Towns et al. 2001 ;Parrish, 2005) dans le but de conserver les nombreux reptiles endémiques de ces îles. Il a ainsi été montré que la présence de R. exulans conduit à un appauvrissement de la communauté de reptiles sur la plan de la diversité spécifique (Whitaker, 1973 ;McCallum, 1986) et de l'abondance (Towns, 1994 ;Parrish, 2005). ...
... Les opérations les plus enrichissantes nous semblent provenir de Nouvelle-Zélande, où des programmes d'éradication du Rat du Pacifique (Rattus exulans) ont été menés dans plusieurs archipels (McCallum, 1986 ;Towns, 1994 ;Towns et al. 2001 ;Parrish, 2005) dans le but de conserver les nombreux reptiles endémiques de ces îles. Il a ainsi été montré que la présence de R. exulans conduit à un appauvrissement de la communauté de reptiles sur la plan de la diversité spécifique (Whitaker, 1973 ;McCallum, 1986) et de l'abondance (Towns, 1994 ;Parrish, 2005). Les espèces nocturnes peuvent être davantage affectées (Whitaker, 1973) par la présence de ce taxon exotique envahissant. ...
... Towns et al. (2001) ont montré que sept espèces de geckos et dix espèces de scinques ont probablement vu leur abondance augmenter après des éradications de rats introduits sur des îles périphériques en Nouvelle-Zélande. Les études existantes attestant de l'impact de R. exulans sur les populations de reptiles indigènes de Nouvelle-Zélande se déroulent dans des conditions qui diffèrent par la compétition pour les ressources alimentaires (McCallum, 1986 ;Towns, 1994 ;Parrish, 2005) et par la prédation, car R. exulans est le seul prédateur présent sur ces îles avant éradication (Whitaker, 1973 ;McCallum, 1986 ;Towns, 1994 ;Parrish, 2005). L'absence de prédateur (autre que R. rattus introduit) se retrouve également dans les îles des Baléares en Méditerranée où Pérez-Mellado et al. (2008) n'ont pas mis en évidence d'effet de la présence de R. rattus sur la densité de P. lilfordi. ...
An eradication of two invasive taxa, the Roof Rat (Rattus rattus) and Ice plants (Carpobrotus spp.), was undertaken in 2011 and 2012 on the protected nature reserve of Bagaud island, located in Port-Cros national Park (south-eastern France). R. rattus eradication was successful while Carpobrotus spp. eradication is still in progress. To assess the effects of R. rattus eradication on island reptile populations (Montpellier Snake Malpolon monspessulanus, European Leaf-toed Gecko Euleptes europaea, Common Wall Lizard Podarcis muralis), a pre-eradication monitoring was conducted in 2010 and 2011, and a post-eradication monitoring in 2013 and 2014. Census was performed with three semi-quantitative methods: (1) three transects of 80 m long and 2 m wide; (2) two quadrats 1225 m(2); (3) five rocky microsites, habitats for E. europaea. Very few individuals of M. monspessulanus were observed. Significant results were obtained only for E. europaea: after eradication, the number of observed juveniles increased and all observed individuals, independently of their age groups, were more outside shelters than inside. These results can be explained by the loss of avoidance behaviour that E. europaea displayed when in presence of R. rattus, and by lower predation pressure, given that both species are nocturnal. The elapsed time since eradication of R. rattus is quite short and some species have not necessarily visibly responded demographically. Additional monitoring in the coming years will provide further insights.
... L'éradication de Carpobrotus spp. a démarré fin 2011 par un arrachage initial sur l'ensemble des stations et se poursuivra jusqu'à élimination complète de la population (Krebs et al. dans . Les opérations les plus enrichissantes nous semblent provenir de Nouvelle-Zélande, où des programmes d'éradication du Rat du Pacifique (Rattus exulans) ont été menés dans plusieurs archipels (McCallum, 1986 ;Towns, 1994 ;Towns et al. 2001 ;Parrish, 2005) dans le but de conserver les nombreux reptiles endémiques de ces îles. Il a ainsi été montré que la présence de R. exulans conduit à un appauvrissement de la communauté de reptiles sur la plan de la diversité spécifique (Whitaker, 1973 ;McCallum, 1986) et de l'abondance (Towns, 1994 ;Parrish, 2005). ...
... Les opérations les plus enrichissantes nous semblent provenir de Nouvelle-Zélande, où des programmes d'éradication du Rat du Pacifique (Rattus exulans) ont été menés dans plusieurs archipels (McCallum, 1986 ;Towns, 1994 ;Towns et al. 2001 ;Parrish, 2005) dans le but de conserver les nombreux reptiles endémiques de ces îles. Il a ainsi été montré que la présence de R. exulans conduit à un appauvrissement de la communauté de reptiles sur la plan de la diversité spécifique (Whitaker, 1973 ;McCallum, 1986) et de l'abondance (Towns, 1994 ;Parrish, 2005). Les espèces nocturnes peuvent être davantage affectées (Whitaker, 1973) par la présence de ce taxon exotique envahissant. ...
... Towns et al. (2001) ont montré que sept espèces de geckos et dix espèces de scinques ont probablement vu leur abondance augmenter après des éradications de rats introduits sur des îles périphériques en Nouvelle-Zélande. Les études existantes attestant de l'impact de R. exulans sur les populations de reptiles indigènes de Nouvelle-Zélande se déroulent dans des conditions qui diffèrent par la compétition pour les ressources alimentaires (McCallum, 1986 ;Towns, 1994 ;Parrish, 2005) et par la prédation, car R. exulans est le seul prédateur présent sur ces îles avant éradication (Whitaker, 1973 ;McCallum, 1986 ;Towns, 1994 ;Parrish, 2005). L'absence de prédateur (autre que R. rattus introduit) se retrouve également dans les îles des Baléares en Méditerranée où Pérez-Mellado et al. (2008) n'ont pas mis en évidence d'effet de la présence de R. rattus sur la densité de P. lilfordi. ...
En 2011, une opération d’éradications simultanées de 2 taxa exotiques envahissants, le Rat noir (Rattus rattus) et les Griffes de sorcière (Carpobrotus spp.) a été entreprise sur l’île de Bagaud, réserve intégrale située au sein du Parc national de Port Cros, dans le sud-est de la France. Un contrôle réalisé en 2014 a permis de conclure au succès de l’éradication de R. rattus. L’éradication de Carpobrotus spp., quant à elle, est encore en cours. Afin de connaître les effets de l’opération d’éradication de R. rattus sur les populations de reptiles de l’île (la Couleuvre de Montpellier Malpolon monspessulanus, le Phyllodactyle d’Europe Euleptes europaea, le Lézard des murailles Podarcis muralis), un suivi pré-éradication a été réalisé en 2010 et 2011, et reconduit post-éradication, en 2013 et 2014. L’échantillonnage pratiqué a été semi-quantitatif selon trois méthodes : (1) trois transects de 80 m de long sur 2 m de large ; (2) deux quadrats de 1225 m² ; (3) cinq microsites rocheux à E. europaea. Très peu d’individus de M. monspessulanus ont été observés. Des résultats significatifs ont été observés seulement pour E. europaea : après éradication, le nombre de juvéniles observés a augmenté et l’ensemble des individus observés, quelle que soit leur classe d’âge, l’ont été plus hors que dans des abris. Ces résultats peuvent s’expliquer par la perte du comportement d’évitement que E. europaea avait en présence de R. rattus et par une pression de prédation plus faible, les deux espèces étant nocturnes. Le temps écoulé depuis l’éradication de R. rattus est assez court et certaines espèces n’ont pas encore nécessairement réagi de façon visible sur le plan démographique. Les suivis complémentaires dans les années à venir apporteront d’autres éléments d’information.
... For this reason, release sites for tuatara should not be on the shore platform (habitat for McGregor's skink on northeast coast and possible release site for Whitaker's skink on southwest coast) or near Forest valley (proposed release site for robust skink and Duvaucel's gecko). The intrinsically low reproductive rate of tuatara (Cree 1994) and the low number of animals likely to be released should ensure that there is ample time for all other reptile species to become established on Mana Island before tuatara are sufficiently numerous to limit population expansion of other species (see Towns 1994). ...
... Whitaker's skinks have a very low intrinsic reproductive rate and appear to be more ecologically specialised than their congeners (Towns 1994). In reviewing translocation methodology for Whitaker's skinks, Towns (1994) recommended that they be released as early as possible in the restoration programme, or at sites well away from species that are better colonisers or predators. ...
... Whitaker's skinks have a very low intrinsic reproductive rate and appear to be more ecologically specialised than their congeners (Towns 1994). In reviewing translocation methodology for Whitaker's skinks, Towns (1994) recommended that they be released as early as possible in the restoration programme, or at sites well away from species that are better colonisers or predators. On islands larger than 100 ha, Towns recommended simultaneous release of all reptile species at widely separated sites. ...
... The Mercury Is lie about 6 km off the eastern Coromandel Peninsula of New Zealand (Fig. 1). All islands in the Mercury group were once linked to the mainland, but the most recent linkages (possibly until about 6000-7000 years ago) were between Korapuki, Green, and Middle Is (Towns 1994). Whereas Middle I. (13 ha) and Green I. (3 ha) have remained free of introduced mammals, Korapuki I. was, until recently, occupied by kiore and rabbits (Appendix 1). ...
... These include three species of native cockroaches, one darkling beetle (Mimopeus elongates), a carabid beetle (Ctenognathus novaezelandiae), the coastal earwig, a species of rhaphidophorid weta, large isopods and giant centipedes (Green, cited in • Spread of honeydew scale from the few remaining ngaio trees to young ngaio and many karo (Towns 2002a) • Rapid recovery of the diurnal shore skink, which at some coastal sites has shown capture rates that increased 5000% over 9 years (Towns 1996) • Redistribution and recovery of two gecko species previously very rare on the island. Duvaucel's gecko is now found throughout the forest and in coastal areas; and the common gecko is now frequently seen feeding on ngaio trunks, flax flowers and pohutukawa flowers (Towns 1994;Eiffler 1995). The latter species is now encountered in coastal habitats at rates equivalent to those on Middle I. (Towns 2002a) • Abundant moko skinks in grassland, flax and coastal areas, and copper skinks, previously regarded as rare on the island (Hicks et al. 1975), are now widespread in forest and coastal areas (Towns 1994) • Sightings of kereru that appear to regularly commute to the island. ...
... Duvaucel's gecko is now found throughout the forest and in coastal areas; and the common gecko is now frequently seen feeding on ngaio trunks, flax flowers and pohutukawa flowers (Towns 1994;Eiffler 1995). The latter species is now encountered in coastal habitats at rates equivalent to those on Middle I. (Towns 2002a) • Abundant moko skinks in grassland, flax and coastal areas, and copper skinks, previously regarded as rare on the island (Hicks et al. 1975), are now widespread in forest and coastal areas (Towns 1994) • Sightings of kereru that appear to regularly commute to the island. These are likely to have spread small numbers of karaka seeds, large numbers of tawapou seed, and two taraire seeds, of which the seedlings subsequently died in 1997 (I.A.E. ...
... A small population of introduced rabbits was also removed by shooting in 1987. Soils, vegetation, invertebrates, lizards, and birds were surveyed in 1974 (Hicks et al. 1975), lizard surveys were repeated in 1985, and lizards and invertebrate diversity and abundance have been documented at least annually (for lizards, biennially) since 1986, with comparative data obtained from nearby islands naturally free of rodents (Towns 1991(Towns , 1994. ...
... Before the Pacific rats were removed, lizard species diversity on Korapuki was half (five species) that recorded on a smaller neighbcu ing island (13 ha Middle Island) free of rats, and a f ^ 'ower proportion of the lizards caught were nocturnal on Korapuki Island (2%) than on Middle Island (65%) (Towns 1991). Lizard relative abundance measured at equivalent coastal sites was significantly higher on Middle Island than on Korapuki Island while rats were present, but on Korapuki it increased up to 30fold at some sites once rats were removed (Towns 1991(Towns ,1994. Significantly, the most rapid response on Korapuki Island was by diurnal shore skinks {Leiolopisma smithi), previously thought to be less vulnerable to the effects of rats than nocturnal species (e.g., . ...
... A less rapid response was found in forested areas on Korapuki Island, but in these sites the previously rare crepuscular copper skink (Cyclodina aenea) is now up to 10 times more abundant than it was before removal of Pacific rats (Towns 1994). ...
Evidence from subfossils and from present distributions confirming range contractions and extinctions of New Zealand amphibians and reptiles is consistent with that from New Zealand landbirds, in which 40% of the fauna, including the largest species, has become extinct in the 1000 years since human arrival. The largest extant species of all higher taxa of herpetofauna—leiopelmatid frogs, tuatara, skinks, and geckos—are extinct on the mainland; 41 % of the extant fauna (27 of 65 species) survive largely or entirely on rat‐free offshore islands; and many species are now restricted to a few isolated locations, remnants of once wider distributions, a pattern called “secondary endem‐ism”. Habitat alterations and occasional human predation may have contributed to range contractions, but the primary factor in extinctions is almost certainly introduced mammals, especially rats. At least three lines of evidence support this view: (1) species diversities and population densities are both far higher on rat‐free islands than on mainland sites and rat‐inhabited islands; (2) nocturnal species have suffered far more than diurnal ones—all populations of tuatara, two of four* species of frogs, the largest Cyclodina skinks, and the largest species of Hoplodactylus geckos are now restricted to islands, most rat‐free; (3) lizard populations on islands from which rats have been exterminated have shown rapid increases in range of habitats occupied, densities attained, and in reproductive success.
... Some population monitoring methods previously used, such as catch per unit effort (CPUE), based on area searching, are not recommended because they are inefficient, biased, and destroy lizard habitat (Towns 1991;Whitaker 1994). An appropriate population monitoring technique for lizards has not been published but the following instructions are adapted from Towns (1975Towns ( , 1991Towns ( , 1994, Whitaker (1994), and Towns & Elliott (1996). ...
... Pitfall trapping has been used to estimate the relative abundance of lizards before and after brodifacoum-poisoning for rodents and on different islands (Towns 1991(Towns , 1994. The number of lizards caught in pitfall traps is influenced by population size as well as by a number of other factors (e.g. ...
... If captured lizards are individually marked then recaptures can be used to estimate the minimum number alive (MNA) at different time points before and after pest control (see Towns 1991Towns , 1994Patterson 1992;Towns & Elliott 1996). The assumptions of a closed population are accepted: viz., that there is no large-scale movement of lizards into or out of the study areas between sampling, and that there are few deaths of lizards eligible to be caught but not caught (Towns 1994;Towns & Elliott 1996 For predetermining toe-clip combinations, there are 150 individual combinations from clipping two toes and 625 from clipping three toes (Whitaker 1994). ...
... However, recovery on Kāpiti Island appears to have been less than at other sites and confined to particular species and habitat types. On Korapuki Island, lizard pitfall captures at a coastal site increased consistently following eradication of kiore, with an almost 10-fold increase over three years (Towns 1991) and a 30-fold increase after 6 years (Towns 1994). In forested sites on the same island there was no measurable increase in lizard captures until six years after the eradication when a sudden increase (up to 10-fold) was observed (Towns 1994). ...
... On Korapuki Island, lizard pitfall captures at a coastal site increased consistently following eradication of kiore, with an almost 10-fold increase over three years (Towns 1991) and a 30-fold increase after 6 years (Towns 1994). In forested sites on the same island there was no measurable increase in lizard captures until six years after the eradication when a sudden increase (up to 10-fold) was observed (Towns 1994). Capture rates for ornate skinks in Zealandia Sanctuary approximately 20 years after eradication of rats and most other invasive mammals were 0.13 captures per pitfall per 24 h in a mouse exclosure and 0.064 captures per pitfall per 24 h outside the exclosure (Nelson et al. 2016 (Hicks et al. 1975, Towns & Atkinson 2004. ...
... These data are consistent with patterns of, and limits to, recovery of skinks elsewhere (e.g. Towns 1991Towns , 1994Newman 1994;Towns and Ferreira 2001). A plateau in captures since 2013 at both sites suggests that the population is now limited by other factors, though it seems unlikely that numbers have reached carrying capacity based on capture rates (e.g . ...
... are consistent with patterns of, and limits to, recovery of skinks elsewhere (e.g. Towns 1991Towns , 1994Newman 1994;Towns and Ferreira 2001). A plateau in captures since 2013 at both sites suggests that the population is now limited by other factors, though it seems unlikely that numbers have reached carrying capacity based on capture rates (e.g . Towns 1994;Romijn 2013). ...
Mainland sanctuaries, where introduced mammalian predators are controlled or excluded, have the potential to improve the conservation status of New Zealand lizards. This is due to the reliance of a large number of species on habitats unavailable on offshore islands. However, despite considerable predator control efforts, lizard populations are still in decline, even in some mainland sanctuaries. The main cause of this failure appears to be that predator control is hard to sustain and largely targeted at protecting bird populations, which require lower levels of predator suppression than lizard populations. Even fenced, mainland, predator-exclusion sites are prone to reinvasions, particularly of mice, which are difficult to exclude at the outset. Episodic irruptions of mice within fenced sanctuaries, and other mammalian predator species in unfenced sanctuaries, can quickly decrease lizard numbers. Small lizard populations are particularly vulnerable. We discuss two case studies to illustrate population dynamics and limitations to understanding mechanisms underlying patterns of population declines in New Zealand skinks: ornate skinks (Oligosoma ornatum) in a fenced mainland site and speckled skinks (O. infrapunctatum) in an unfenced mainland site. We also speculate about the effects on lizards of native and non-native birds and introduced social insects, including wasps and ants. Understanding biological interactions and obtaining more species- and situation-specific data for lizards will provide information on limits to recovery, detection time frames after management actions, risks and benefits of habitat enhancements and density targets for introduced species where total eradication is impractical.
... f Hitchmough (1982); g Hare et al. (2007); h Hare and Cree (2005); i Whitaker (1982), Robinson (1985), Anastasiadis and Whitaker (1987), and Cree (1994); j Macavoy (1976), Cree (1994), Cree and Guillette (1995), Rock et al. (2000), and Rock and Cree (2003); k Robinson (1985); Cree (1994, pers. obs.), Cree and Guillette (1995), Sheehan (2002); Cree et al. (2003), and Sheehan et al. (2004); l Towns (1994); Ferreira (2001), Scharf et al. (2015), and K. Miller (pers. comm.); ...
... comm.); t Towns (1975), Cree (1994), Towns and Ferreira (2001), and Miller et al. (2010); u Southey (1985), Towns (1994), Cree (1994) (2) mating occurs during winter or spring in N. gemmeus, but during late summer or autumn in the other three species followed by a more prolonged period of sperm storage. Grey bars ¼ vitellogenesis (vg); black bars ¼ pregnancy (preg); m (ss) ¼ mating followed by sperm storage; ov ¼ ovulation Note conceptus (c) in each of the two pigmented uteri. ...
New Zealand lizard species are characterised by their high incidence of viviparity (99 % of taxa) and ‘slow’ life histories. Female geckos and skinks typically mate and begin vitellogenesis in autumn, store sperm over winter and ovulate in spring. Pregnancies usually last at least 3 months, but gestation length, which is temperature dependent, may reach 14 months in some geckos (especially nocturnally foraging species). Some female geckos and skinks reproduce less than annually. Male geckos and skinks exhibit spermiogenesis during summer and/or autumn, with prolonged or continuous spermatocytogenesis and no period of complete testicular regression. Several features (autumn mating with prolonged vitellogenesis, possibility of a secondary mating season in spring, prolonged pregnancies with sometimes less-than-annual reproduction in females) have parallels with Tasmanian and South American lizards from similarly cool climates. Parallels also exist with New Zealand’s egg-laying tuatara (Sphenodon punctatus), including less-than-annual reproduction, prolonged embryonic development and continuous spermatocytogenesis. Compared with sympatric skinks, geckos from temperate zones in New Zealand appear distinctive in their ability to retain fully developed offspring in utero over winter, to begin vitellogenesis before pregnancy has ended and to maintain a stable size of the testes and abdominal fat bodies year-round. New Zealand lizards generally exhibit traits at the slow end of the life-history continuum for small-bodied lizards. In particular, New Zealand geckos are exceptionally long-lived (at least 3–5 decades in the wild in several species), and, with clutch sizes ≤2, have extremely low annual reproductive output. Some ideas for future research are presented.
... The biotic composition of islands in the MIED is largely a function of island origin (e.g. Towns 1994Towns , 2002bTowns et al. 1997), notably isolation due to sea level rise following the last glaciations (e.g. Hayward 1986). ...
... In combination with slow population growth by introduced species of reptiles (e.g. Towns 1994), reactivation of the proposed interaction web was assumed to involve timescales of decades or perhaps centuries. (Hicks et al. 1975) Invertebrates ...
Globally, one in five reptile species is threatened with extinction, with invasive species a leading cause of extinction risk. Translocations could alleviate the risk of extinction through the establishment of populations in locations from which invasive predators have been removed. But do translocations represent a viable strategy for reptile conservation? We investigate the numerical and genetic outcomes of translocations of reptiles as reintroductions to islands cleared of introduced mammals around New Zealand. These reintroductions included nine populations of tuatara (Sphenodon punctatus), ten populations of six species of geckos and 24 populations of 12 species of skinks on a total of 24 islands. Reintroduced populations are often relatively small, which exposes them to associated demographic and genetic problems. We compared criteria for success based on abundance with available genetic data for four species of reintroduced reptiles. Three populations of skinks showed some loss of genetic heterozygosity but have nonetheless met most criteria for numerically viable populations. Whether loss of genetic variability might have long-term consequences for persistence is unclear because the genetic basis for population viability is still debated. We found that the success of reintroductions can be influenced by complex interactions between numerical, genetic and administrative constraints on project design. We thus suggest that obtaining data on the outcomes of reptile recovery will require managers to avoid mixing populations for pre-emptive genetic rescue, and a commitment to long term ecological and genetic studies.
... The biotic composition of islands in the MIED is largely a function of island origin (e.g. Towns 1994Towns , 2002bTowns et al. 1997), notably isolation due to sea level rise following the last glaciations (e.g. Hayward 1986). ...
... In combination with slow population growth by introduced species of reptiles (e.g. Towns 1994), reactivation of the proposed interaction web was assumed to involve timescales of decades or perhaps centuries. (Hicks et al. 1975) Invertebrates ...
The progressive removal of invasive mammals from the Mercury Islands has led to over 25 years of field study designed to test the processes of restoration and natural recovery of these seabird-driven island ecosystems. Resulting from this work, four key restoration questions can now be identified as fundamental to designing island restoration programmes The questions are: what is the regional context of the island (biogeography); how does each island ecosystem operate (ecosystem function); how have invasive species changed the ecosystem (response effects); and how can progress towards a restoration goal be defined (outcome measures)? Examples of how these questions influenced restoration in the Mercury Islands are provided with Korapuki Island as a case study. However, unpredicted and subtle responses can eventuate. In the Mercury Islands these included a hitherto unknown honeydew parasite-bird-gecko food web and subtle effects of rats on plant regeneration. Promising outcome measures of restoration progress are now being developed, including indices of marine influence using stable isotopes of nitrogen and the use of network analysis to analyse the composition of invertebrate food webs.
... There was never any intention that the fence should be rat or mouse proof, although it is known that these rodents prey on reptiles (Newman 1994;Towns 1994;Lettink & Cree 2006). It was thought that the fence would exclude several introduced mammals which prey on geckos, as well as cattle, which were causing damage to the Coprosma bushes (Duggan 1991), thereby benefiting the jewelled gecko population. ...
... In summary, due to their arboreal nature, nocturnal activity, ability to move through dense vegetation, high potential density in jewelled gecko habitat (particularly in rank pasture or areas of dense ground cover) (Chapter 2) and proven impact on other native skinks and geckos (e.g. Newman 1994;Towns 1994;Lettink & Cree 2006;Wedding 2007), ship rats and mice are likely to be significant predators of jewelled geckos. (Esler, 1967;Allen et al., 1992;Wilson, 1994;Rogers, 1996;Widyatmoko & Norton, 1997;Buxton et al. 2001). ...
... We found evidence to support our hypothesis that the expansion of coastal dunes and grasslands can lead to an increase in the size of the E. argus population. Habitat expansion and restoration, such as the removal of threats within habitats, can lead to an increase in population (Towns 1994;Pike et al. 2011). In particular, species found only in certain habitats may be greatly affected by habitat restoration efforts (Amo et al. 2007). ...
The endangered species Mongolian racerunner (Eremias Argus), with a limited distribution in South Korea, is found only in sand dunes near waterside and forests. Therefore, species trends in this particular habitat are directly affected by habitat contamination and destruction. In this study, we examined the effects of coastal sand dune restoration on the distribution and population of E. argus. We conducted a field survey in Baramarye special protection zone, called Baramarye Coast, a part of the Taeanhaean National Park, during April and June 2016. We searched and recorded the location of E. argus and tagged them using the toe clipping method. The size of the E. argus population was estimated using the Peterson method. After the restoration of coastal sand dunes in Baramarye Coast, the population size of E. argus increased by 126-137 (21.1-55.7%) compared with that in 2008. The home range of E. argus in coastal sand dunes was significantly expanded by 4.8-fold for 95% Kernel density (KD) and 3.6-fold for 50% KD compared with that in 2008. Moreover, we confirmed that the distribution of E. argus was expanded to the restored area. Our study showed that in situ conservation is effective for endangered E. argus, distributed in particular environments such as coastal region. This study provides one more reason why coastal region must be conserved.
... This may be less of an issue in species with high reproductive output, for example, a fish endemic to Texas, Gambusia nobilis, was able to produce in excess of 1000 young per year from a founder stock of 30-40 individuals (Philippart 1995). In comparison, Whitaker's skink (Cyclodina whitakeri) can only give birth to 2-4 young annually (Towns 1994) and would require 250-500 gravid females to produce 1000 offspring. In species that have lower reproductive outputs, it may not be viable to release juveniles if that age-class is known to have lower survival rates compared to sub-adults or adults, particularly if there is not a large enough source population available. ...
Animal behaviour can affect the outcome of conservation translocations. It is important to understand the behaviour of the species being considered for translocation and how its behaviour varies over life stages. There may be uncertainty about what life stages are best as founders for release back into wild populations. A technique called head‐starting whereby juvenile life stages are raised in captivity and then released is one potential pre‐release strategy. However, juveniles of many species have a dispersive role in the life cycle, potentially raising difficulties for establishing new populations due to dispersal from the intended habitat following release. For this study, we compared aspects of the behaviour of captive adult and neonate pygmy bluetongue lizards (Tiliqua adelaidensis) – an endangered species for which translocation is likely to be an important management strategy – to determine if neonate behavioural characteristics are appropriate for their translocation. We filmed adult and neonate pygmy bluetongue lizards and compared their behaviour. We also filmed adults over an activity season to compare seasonal behaviour. Behavioural parameters measured included basking time, burrow exits, burrows occupied and walking the perimeter wall. Neonates basked significantly more than adults in summer and autumn. Neonates are likely to be basking more than adults because they are in a stage of rapid growth and need to gain body mass before the winter inactivity period. Neonates exited burrows more often than adults and used a greater number of burrows. These results indicate neonate lizards are actively exploring their habitat. Neonates are unlikely to be as suitable for translocation as they are actively moving about and more likely to be predated upon or disperse from the translocation site. Our finding can be applied to other species that have active juvenile life stages and are at particular risk of predation due to their small size.
... Dans les années 90, Towns (1994) décrivait un programme mis en place afin d'améliorer le statut de conservation du très rare Scinque de Whitaker (Cyclodina whitakeri) confiné à l'origine sur une île dans un reliquat d'habitat favorable de moins de 20ha et dont certains individus (28) ont été transférés sur l'Ile de Korapuki en Nouvelle Zélande après éradication des rats du Pacifique (Rattus exulans). La réponse de cinq autres espèces de reptiles résidentes (scinques et geckos) avaient également été enregistrée suite aux opérations d'élimination des rats. ...
... Este resultado ha estado en la mira y ha sido alcanzado mediante la erradicación de roedores. Para 1998, se han removido los roedores en 25 islas en Nueva Zelandia brindando beneficios medibles o potenciales para el tuatara (Sphenodon sp.), 8 especies de salamanquesas y 12 especies de lagartijas (familia Scincidae) (Cree et al. 1995; Towns 1994; Towns et al. 2007). A nivel de ecosistemas, se ha documentado la restauración de bosques indígenas como un resultado del incremento substancial en el número de arbustos y semillas de árboles después de la erradicación de la rata noruega (Allen et al. 1994) Donde existe infraestructura, los roedores se alimentan, mordisquean agujeros, orinan, defecan y anidan en áreas que les pueden proporcionar refugio; a menudo en las viviendas habitadas por los humanos. ...
... This result has been targeted and achieved through rodent eradication. By 1998, rodents had been removed from 25 islands within New Zealand providing measurable or potential benefits for Tuatara (Sphenodon sp.), 8 species of geckos, and 12 species of skink (Cree et al. 1995; Towns 1994; Towns et al. 2007). At the ecosystem-level, indigenous forest restoration has been documented as a result of substantial increase in the number of shrub and tree seedlings after Norway rat eradication (Allen et al. 1994). ...
... In New Zealand, the benefits of using brodifacoum (or related compounds) to eradicate rats and/or rabbits from offshore islands are also becoming apparent. For example, eradication of rats from Korapuki Island (using bromadiolone, a second-generation anticoagulant related to brodifacoum) in 1986 resulted in a 10-fold increase in lizard numbers in 3 years (Towns 1991) and a 30-fold increase in 6 years (Towns 1994). Similarly, in 1996, the successful removal of rats from Kapiti Island has resulted in a significantly improved survival rate for stitchbirds and saddlebacks, and benefits to other taxa are expected (Empson & Miskelly 1999). ...
... Although predator eradication and control in 'mainland island' situations has yet to result in significant improvements in lizard populations, the experience from the eradication of introduced predators on real islands shows their removal having immense benefit. When released from predation island lizard populations usually respond rapidly and in spectacular fashion, showing not just greater population densities but changed spatial distribution, habitat use, behaviour and body size (Towns 1991(Towns , 1994(Towns , 1996Newman 1994;Brown 1997;Rufaut & Clearwater 1997). ...
In the interest of forest conservation, DOC Science Publishing supports paperless electronic publishing. When printing, recycled paper is used wherever possible.
... Eradications of non-native rodents have provided the most numerous examples of broad ecological benefits. Positive effects of rat removal include the regeneration of native forest, 13 the enhancement of breeding performance in native birds, 14 the increase in abundance of native invertebrates, 15,16 lizards 17,18 and small mammals 19 and the re-establishment of seabird colonies previously extirpated. Similarly, the removal of non-native plants can have broad ecological outcomes, from the re-establishment of native plant species 20 to the recovery of soil properties 21 -23 and the restoration of ecosystem-level processes. ...
Background
Black rats Rattus rattus and mat-forming iceplants, Carpobrotus aff. acinaciformis and Carpobrotus edulis are pervasive pests on Mediterranean islands. Their cumulative impacts on native biotas alter the functioning of island ecosystems and threaten biodiversity. We report here the first attempt to eradicate both taxa from a protected nature reserve in south-eastern France (Bagaud Island). In order to minimize unwanted hazardous outcomes and produce scientific knowledge, the operations were embedded in a four-step strategy including initial site assessment, planning, restoration and monitoring.ResultsTrapping, which yielded to the removal of 1 923 rats in 21 045 trap-nights, allowed removing a substantial proportion of the resident rat population and reducing the amount of rodenticide delivered in the second stage of the operation. Forty tons of Carpobrotus spp. were manually up-rooted from of a total area of 18 000 m2; yet careful monitoring over a decade is still required to prevent germinations from the seed bank.Conclusion
Two years after the beginning of the interventions, both eradication operations are still ongoing. Biosecurity measures have been implemented to reduce reinvasion risks of both taxa. With the long-term monitoring of various native plants and animals, Bagaud Island will become a reference study site for scientific purposes.
... In many instances the removal of rodents has resulted in substantial increases in the abundance of reptiles (Towns 1991). For example, the number of skinks on Korapuki Island increased 30-fold within five years of rats being removed (Towns 1994). Consequently, mitigation measures are not planned for reptiles on LHI. ...
Like many oceanic islands, World Heritage listed Lord Howe Island (LHI), 760 km north-east of Sydney, Australia, has populations of invasive rodents. The house mouse ( Mus musculus ) probably arrived around 1860, and the ship rat ( Rattus rattus ) in 1918. Both species have had significant impacts on the island’s biodiversity, with rats implicated in the extinction of at least 20 species (or subspecies) of birds, invertebrates and plants. These exotic rodents remain a threat to many endemic species, so much so that predation by ship rats on LHI is listed as a Key Threatening Process under both New South Wales and Australian environmental legislation. A feasibility study (in 2001) concluded that eradication of both rats and mice was technically feasible, and a subsequent cost-benefit study (in 2003) demonstrated that costs of the eradication would be quickly offset by discontinuation of the current rat control programme and increased yields of commercial palm seed. A plan to eradicate exotic rodents on LHI was prepared in 2009. Technical challenges include: the presence of numerous threatened island endemics, several of which could potentially be placed at risk; a permanent human population of approximately 350, their pets and livestock; and a well-developed tourist industry. Several species of threatened fauna will be housed in captivity for the duration of the operation to mitigate the risk of primary and secondary poisoning. The presence of a large human settlement necessitates modification to the customary strategy. Within uninhabited areas, bait will be aerially broadcast, whereas within the settlement, bait will be hand broadcast or placed in bait stations. Livestock will either be eliminated from the island before the eradication or aggregated into small enclosures. Community support is vital to the success of the operation, and extensive consultation has been, and will continue to be, a major component of the eradication programme.
... The reptile fauna of New Zealand has suffered severe range contractions and dramatic reductions in abundance since the arrival of humans, c. 1000 years ago (Davidson 1984;Towns 1994;Craig et al. 2000). Once widespread throughout the country, many endemic species are now restricted to small, remnant, pseudo-endemic populations confined to predatorfree offshore islands (Towns & Robb 1986;Daugherty et al. 1990;Towns & Daugherty 1994). ...
Tiritiri Matangi Island is one of the oldest community-driven island restoration projects in New Zealand. While great effort has been directed towards recovery of vegetation and avian communities since the 1980s, restoration of the island’s reptile fauna has not been initiated until early 2000s. Tiritiri Matangi supports only three remnant reptile species, which is considerably low given the island’s size and geographic location. In recognition of this and the importance of reptiles in ecosystem function, translocations of several reptile species have been undertaken. The translocations presented opportunities for integrating in-depth scientific studies in regard to applied conservation management of native reptiles with experimental approaches. This review summarises research efforts on Tiritiri Matangi to date, including post-graduate studies that have contributed to: (1) baseline information on resident species (Oligosoma moco, O. aeneum, Woodworthia maculata, O. smithi & Naultinus elegans); (2) understanding the importance of seabird co-habitation for Sphenodon punctatus; (3) post-release behaviours (dispersal and habitat selection) of Hoplodactylus duvaucelii; (4) body colour adaptation of O. smithi following translocation; (5) quantifying avian predation on lizard populations; and (6) measuring the short-term success of all translocations. Numerous research opportunities remain, either on existing populations or future translocations to the island. Emphasis has been placed on the involvement of public and local community volunteers in all reptile research. These groups are key stakeholders in the restoration of Tiritiri Matangi. Measurement of translocation success for New Zealand reptiles is dependent on long-term monitoring (> 10 years) and research, since these endemic reptiles exhibit distinctive characteristics such as slow maturity, low reproductive rates, and very high longevity. The process of restoration of a fully functioning New Zealand ecosystem is similarly slow, therefore, long-term study or monitoring will also enable assessment of the island’s restoration outcome over time.
... However, such impact has apparently never been assessed in Southland, largely because of the difficulty of monitoring lizard populations in heavily vegetated habitats. Spurr and Powlesland (2000) summarised lizard population monitoring techniques listed in Towns (1975Towns ( , 1991Towns ( , 1994, Whitaker (1994), and Towns & Elliott (1996) (articles not seen by the present authors), and recognised that appropriate methods for widespread monitoring of New Zealand's reptile populations have not been published. The methods favoured by Spurr & Powlesland (2000) include pitfall trapping and minimum number alive (capture-mark-recapture). ...
... Founder popu-lations are generally small because of the limitations of harvesting source populations, and opportunistic predation of founders may be great enough to exacerbate the effects associated with K-strategist lizard species. For example, following the translocation of highly threatened Cyclodina whitakeri to Korapuki Island, population models suggested that the population became highly vulnerable to collapse if predation of adults exceeded 5% per annum (Towns 1994). ...
Dietary analyses were carried out on four species of native birds on Tiritiri Matangi and Motuora Islands, New Zealand, between February 2007 and February 2008. We examined regurgitated pellets of kingfishers, moreporks and swamp harriers, and the faeces of pukeko. Remains of lizards were found in 88% and 43% of regurgitated kingfisher pellets on Tiritiri Matangi and Motuora, respectively. All remains belonged to one species, Oligosoma moco. No evidence of lizard predation was found for the other three bird species. Translocation of lizards to areas supporting a high abundance of kingfishers should take avian predation risk into account.
... Because of the proximity to an urban area, domestic cats are likely to be a particular problem, and during the night surveys for striped geckos domestic cats were frequently seen in the forest in the search area. However, there is no evidence that the predator guild or density has changed in the recent past, or is changing now, so it seems that striped geckos can survive in their presence, albeit probably at a considerably lowered population density (cf. the response of gecko populations to release from predation pressure (Newman 1994, Towns 1994). ...
Abstract The striped gecko,(Hoplodactylus stephensi,Robb 1980) is one of the rarest
... Further, from limited data available for five species in the genus Cyclodina (excluding C. macgregori), the general pattern of reproduction in these lizards is for a single annual litter to be produced in late summer, and the litter size to be consistently small: around three offspring/ female per year (Cree 1994). Towns (1994), though, suggests that reproduction in C. whitakeri is biennial. It is also known that individual C. macgregori can be long lived: the female first caught in February 1986 was recaptured again during 1993/94 (C. ...
During 1984 an unsanctioned farm road was constructed through the known range of McGregor's skink (Cyclodina macgregori) on Mana Island (217 ha). Monitoring of the island's lizard populations commenced in 1986 to assess the effects of habitat changes caused by the construction of the road. Between 1987/88 and 1988/89 the capture rate (pitfall traps) for McGregor's skink declined significantly. This decline is attributed to increased predation by mice (Mus musculus) following a buildup of mouse numbers after cattle (the only stock then present) were removed from the island in 1986. In August 1989 a successful programme to eradicate mice was implemented, and no mice or their sign have been seen since February 1990. Since then, the capture rates have increased significantly for C. macgregori, the gecko (Hoplodactylus maculatus), and the Cook Strait giant weta (Deinacrida rugosa) (Orthoptera). Even though individual C. macgregori show strong site fidelity and are potentially long‐lived (10+ years), only three of 64 caught to April 1988 have been recaptured since the last mouse was trapped. Adults appeared more vulnerable to predation than juveniles. All captures of McGregor's skink on Mana Island were made within a small area (
... In New Zealand, the benefits of using brodifacoum (or related compounds) to eradicate rats and/or rabbits from offshore islands are also becoming apparent. For example, eradication of rats from Korapuki Island (using bromodiolone, a second-generation anticoagulant related to brodifacoum) in 1986 resulted in a 10-fold increase in lizard numbers in 3 years (Towns 1991) and a 30-fold increase in 5 years (Towns 1994). Eradication of rats from other islands (using brodifacoum) is producing similar results in terms of range of habitat occupied, densities attained, and in reproductive success of lizards (Newman 1994;Towns & Dougherty 1994). ...
Brodifacoum, an anticoagulant used in cereal‐based baits for the control of vertebrate pests, especially rodents, may be accidentally ingested by non‐target species. In birds, its acute toxicity varies from an LD50 of < 1 mg/kg in pukeko to >20 mg/kg in paradise shelduck. Fourteen indigenous and eight introduced bird species have been reported killed by field use of brodifacoum in New Zealand. Populations of three species (western weka, Stewart Island weka, and pukeko) have been severely reduced in poisoned areas. There are no published data on the acute toxicity of brodifacoum in bats, reptiles, or amphibians. Invertebrates are unlikely to be killed by anticoagulants. Because of the high toxicity of brodifacoum, all vertebrates that eat baits or poisoned prey are at risk. Brodifacoum is only slowly eliminated from the liver, and therefore accumulates in vertebrates if there are repeated exposures to the toxin, which increases the risk of death. In New Zealand, indigenous non‐target species most at risk from eating brodifacoum in cereal‐based baits are herbivorous and omnivorous birds (e.g., weka, pukeko, and saddleback). The species most at risk from secondary poisoning are predatory and scavenging birds such as weka, Australasian harrier, southern black‐backed gull, and morepork. Insectivorous birds, bats, lizards, and frogs are probably least at risk. However, laboratory and field trials are essential to determine the actual risks, and reduce scientific uncertainties. The risks of pest control must be carefully balanced against the benefits. These benefits can be substantial where introduced mammals threaten native species with extinction.
... Phormium tenax provides food for a number of native animals. Geckos have been encountered among Phormium flowers (Towns 1994), and flax nectar was recorded as the most important food for breeding tui in the Chatham Islands (Dilks et al. 1998). similarly, P. tenax seed is also an important food for birds such as red-crowned kakariki (Cyanomorphus novaezelandiae), consisting of up to 17% of food eaten in late summer and autumn on Tiritiri-Matangi Island (Dawe 1979). ...
We review the biosystematics, chemistry, phenology, ecology, and cultural and economic uses of Phormium tenax, a widespread iconic New Zealand monocotyledon. Phormium tenax is endemic to New Zealand, Norfolk Island, and the Chatham Islands, and is distinguished from the sole other member of the genus, P. cookianum, by its erect trigonous seed capsules and red flowers, despite incomplete barriers to hybridisation. Flowers produce abundant nectar and are bird pollinated. Seed is orthodox and tolerates drying, while chilling overcomes dormancy. Rich, well‐drained alluvial and organic soils encourage abundant growth in P. tenax but prolonged flooding and drought reduce growth and survival. Lack of tolerance to both frost and low mean annual temperatures distinguish its environmental niche from that of P. cookianum, but further research is required to characterise these differences more accurately. Phormium tenax is a significant component of vegetation on coastal cliffs, slopes, and dunelands; in estuarine shrublands; and lake margin and freshwater communities. Wide morphological variation in Phormium has led to cultivar development by Maori for weaving and by horticulturalists for ornamental garden use. Phormium tenax is important in many ecological communities as a food source, and is often used in restoration and revegetation plantings.
... Such a statement can be supported by L. telfairii's ability to persist on Round Island during the presence of exotic herbivores and their subsequent rapid increase in population size following the removal of goats and rabbits (North et al., 1994). Since species previously thought to be highly specialized in their ecological requirements have been reported to use more heterogeneous habitats in new sites at which they have been introduced (Towns, 1994), even greater adaptability might be anticipated from more " generalist " species such as L. telfairii. The results of this study highlight the importance of air and ground temperatures in determining microhabitat use in L. telfairii and supports Towns' (1994) recommendation that a thermal gradient be provided for translocated reptiles. ...
The successful eradication of introduced rodents from islets off the coast of Mauritius has led to local conservation bodies investigating the possibility of translocation as a measure of safeguarding endemic reptile populations. The present study was the first to determine the habitat and microhabitat requirements of Telfair's skinks (Leiolopisma telfairii) on Round Island, Mauritius, with a view to aiding future translocation projects to islands within their historic range. Contrasting preferences found for Telfair's skink at macro- and micro- habitat levels underline the importance of sampling at multiple ecological scales in such investigations. Significantly fewer sightings of L. telfairii were recorded in bare rock habitats compared to more vegetated habitats. Conversely, at a microhabitat scale principal component analysis indicated structural characteristics were the primary determinant of microhabitat choice. The first dietary analysis of Telfair's skinks confirmed their status as omnivores. Cockroaches (Blattodea spp.) appeared to be a primary food source. Four exotic plant species were also present in faecal samples and the potential for L. telfairii to aid their dispersal is discussed. Implications for the long-term management and proposed translocation of Telfair's skinks are discussed.
... En algunas islas de Nueva Zelanda que han sido liberadas de especies introducidas se presentaron incrementos significativos en las densidades poblacionales de lagartijas (Towns, 1991;1994). En Isla Rasa es probable que se presenten cambios en las poblaciones de reptiles, por lo que se debe tener información acerca de su abundancia. ...
... Large Cyclodina skinks are widely regarded as being extremely vulnerable to rodent predation (Ogle 1987;Towns & Daugherty 1994;Towns 1994). The only sites where any of marbled skink C. oliveri, Mokohinau skink Cyclodina sp., McGregor's skink, robust skink C. alani or Whitaker's skink have survived in the presence of rodents are on Little Barrier Island (marbled skinks in the presence of kiore Rattus exulans ), Great Barrier Island (marbled skinks in the presence of ship rats Rattus rattus , kiore and mice), Mana Island (McGregor's skinks formerly in the presence of mice) and Pukerua Bay. ...
A rodent index trap line was established at Pukerua Bay on 8 August 1995 to identify the species and relative abundance of rodents present, and to determine whether any of the rodent species present were consuming lizards. Fifty pairs of rat and mouse snap-traps were spaced at 25 metre intervals and totally surrounded the only area where Whitaker's skink Cyclodina whitakeri is known to have survived on the mainland (see Towns 1992a). The traps were baited with a mixture of peanut butter and rolled oats, and were set for three consecutive nights through to 11 August. A total of 71 house mice Mus musculus (30.4/100 corrected trap-nights) and no rats were caught during the trapping session. The only non-target captures were two immature female weasels Mustela nivalis caught in rat traps 50 metres apart, about 100 metres from the 0.5 ha area where Whitaker's skinks are known to occur. Stomach contents of 67 mice and the two weasels were examined. None of the mice had lizard remains in its stomach, but one of the weasels had its
... The general scarcity of kiore during our visit was anticipated, as this species is usually in quite low numbers during September, as a consequence of the annual winter die off prior to the summer breeding season. Nevertheless, the deleterious effect kiore have on fauna and flora is now well documented (Campbell 1978;Towns 1991Towns , 1994, and we believe, well demonstrated on Fanal. In particular we note that the numbers of smaller petrel and of are much lower than would otherwise be expected for an island the size of Fanal. ...
The two volumes of this handbook provide a comprehensive account of the emerging and vibrant science of the ecological restoration of both habitats and species. Ecological restoration aims to achieve complete structural and functional, self-maintaining biological integrity following disturbance. In practice, any theoretical model is modified by a number of economic, social and ecological constraints. Consequently, material that might be considered as rehabilitation, enhancement, re-construction or re-creation is also included. Principles of Restoration defines the underlying principles of restoration ecology, in relation to manipulations and management of the biological, geophysical and chemical framework. The accompanying volume, Restoration in Practice, provides details of state-of-the-art restoration practice in a range of biomes within terrestrial and aquatic ecosystems. The Handbook of Ecological Restoration will be an invaluable resource to anyone concerned with the restoration, rehabilitation, enhancement or creation of habitats in aquatic or terrestrial systems, throughout the world.
The two volumes of this handbook provide a comprehensive account of the emerging and vibrant science of the ecological restoration of both habitats and species. Ecological restoration aims to achieve complete structural and functional, self-maintaining biological integrity following disturbance. In practice, any theoretical model is modified by a number of economic, social and ecological constraints. Consequently, material that might be considered as rehabilitation, enhancement, re-construction or re-creation is also included. Principles of Restoration defines the underlying principles of restoration ecology, in relation to manipulations and management of the biological, geophysical and chemical framework. The accompanying volume, Restoration in Practice, provides details of state-of-the-art restoration practice in a range of biomes within terrestrial and aquatic ecosystems. The Handbook of Ecological Restoration will be an invaluable resource to anyone concerned with the restoration, rehabilitation, enhancement or creation of habitats in aquatic or terrestrial systems, throughout the world.
The two volumes of this handbook provide a comprehensive account of the emerging and vibrant science of the ecological restoration of both habitats and species. Ecological restoration aims to achieve complete structural and functional, self-maintaining biological integrity following disturbance. In practice, any theoretical model is modified by a number of economic, social and ecological constraints. Consequently, material that might be considered as rehabilitation, enhancement, re-construction or re-creation is also included. Principles of Restoration defines the underlying principles of restoration ecology, in relation to manipulations and management of the biological, geophysical and chemical framework. The accompanying volume, Restoration in Practice, provides details of state-of-the-art restoration practice in a range of biomes within terrestrial and aquatic ecosystems. The Handbook of Ecological Restoration will be an invaluable resource to anyone concerned with the restoration, rehabilitation, enhancement or creation of habitats in aquatic or terrestrial systems, throughout the world.
The New Zealand endemic gecko genus Hoplodactylus is revised. Two species are recognized: Hoplodactylus duvaucelii (Duméril & Bibron, 1836) from the North Island and some near-shore islands, and H. tohu n. sp., which was formerly widespread throughout the South Island but is presently restricted to some islands in the Cook Strait region. H. delcourti (Bauer & Russell, 1986) is retained in Hoplodactylus sensu lato in the interest of taxonomic stability, pending further research, but is probably neither congeneric nor from New Zealand.
At present, some 11,440 extant reptile species have been described on Earth and several hundred new species have been described each year since 2008 (Uetz & Hosek 2018). As grazers, seed dispersers, predators, prey and commensal species, reptiles perform crucial functions in ecosystems (Böhm et al. 2013).
Reptiles are a hugely diverse group of animals (Pincheira-Donoso et al. 2013) and are adapted to live in a wide range of tropical, temperate and desert terrestrial habitats, as well as freshwater and marine environments (Böhm et al. 2013). That said, reptile species usually have narrower geographic distributions than other vertebrate taxonomic groups (e.g. birds or mammals), and this coupled with particular life history traits makes some reptile species particularly vulnerable to anthropogenic threats (Böhm et al. 2013, Fitzgerald et al. 2018). For example, some turtle species are
16
typically very long lived, take years to reach full maturity, produce small clutches and have variable reproductive success, which means that they are vulnerable to loss of adults and take many years to recover from declines (Congdon et al. 1994).
Multiple threats to reptile populations have been identified and are implicated in species declines (Gibbons et al. 2000, Todd et al. 2010). These threats include habitat modification, loss and fragmentation (Neilly et al. 2018, Todd et al. 2017), environmental contamination (Sparling et al. 2010), potentially unsustainable harvesting and/or collection (van Cao et al. 2014), invasive species (Fordham et al. 2006), climate change (Bickford et al. 2010, Sinervo et al. 2010) and disease and parasitism (Seigel et al. 2003). Also, due to their physical characteristics, reputation (warranted or otherwise) and in some cases venomous bites, some reptile species are viewed with distaste, which leads to apathy around their conservation (Gibbons et al. 1988). According to the IUCN Red List, of 10,148 reptile species that have been assessed, some 21% are considered to be threatened (IUCN 2021). Extinction risks are particularly high in tropical regions, on oceanic islands and in freshwater environments (Böhm et al. 2013), with some 59% of turtle species assessed at risk of extinction (van Dijk et al. 2014). Reptiles with specialist habitat requirements and limited ranges that are in areas accessible to humans are likely to face greater extinction risks (Böhm et al. 2016). Many island reptile species are endemic and are therefore even more vulnerable to extinction as a result of human disturbance (Fitzgerald et al. 2018). For a comprehensive summary of threats to different families of reptiles see Fitzgerald et al. (2018).
Evidence-based knowledge is key for planning successful conservation strategies and for the cost-effective allocation of scarce conservation resources. To date, reptile conservation efforts have involved a broad range of actions, including protection of eggs, nests and nesting sites; protection from predation; translocations; captive breeding, rearing and releasing; habitat protection, restoration and management; and addressing the threats of accidental and intentional harvesting. However, most of the evidence for the effectiveness of these interventions has not yet been synthesised within a formal review and those that have could benefit from periodic updates in light of new research.
Targeted reviews are labour-intensive and expensive. Furthermore, they are ill-suited for subject areas where the data are scarce and patchy. Here, we use a subject-wide evidence synthesis approach (Sutherland et al. 2019) to simultaneously summarize the evidence for the wide range of interventions dedicated to the conservation of all reptiles. By simultaneously targeting all interventions, we are able to review the evidence for each intervention cost-effectively, and the resulting synopsis can be updated periodically and efficiently. The synopsis is freely available at www.conservationevidence.com and, alongside the Conservation Evidence online
17
database, is a valuable asset to the toolkit of practitioners and policy makers seeking sound information to support reptile conservation. We aim to periodically update the synopsis to incorporate new research. The methods used to produce the Reptile Conservation Synopsis are outlined below.
This synthesis focuses on global evidence for the effectiveness of interventions for the conservation of reptiles. This subject has not yet been covered using subject-wide evidence synthesis. This is defined as a systematic method of reviewing and synthesising evidence that covers broad subjects (in this case conservation of multiple taxa) at once, including all closed review topics within that subject at a fine scale, and analysing results through study summary and expert assessment, or through meta-analysis. The term can also refer to any product arising from this process (Sutherland et al. 2019). This global synthesis collates evidence for the effects of conservation interventions on terrestrial, aquatic and semi-aquatic reptiles, including all reptile orders, i.e. Crocodilia (alligators, crocodiles and gharials), Testudines (turtles and tortoises), Squamata (snakes, lizards and amphisbaenians) and Rhynchocephalia (tuatara). This synthesis covers evidence for the effects of conservation interventions for wild reptiles (i.e. not in captivity). We have not included evidence from the substantial literature on husbandry of marine and freshwater reptiles kept in zoos or aquariums. However, where these interventions are relevant to the conservation of wild declining or threatened species, they have been included, e.g. captive breeding for the purpose of increasing population sizes (potentially for reintroductions) or gene banking (for future release).
Rediscovery of living populations of a species that was presumed to be extirpated can generate new narratives for conservation in areas suffering from losses in biodiversity. We used field observations and DNA sequence data to verify the rediscovery of the Critically Endangered scincid lizard Emoia slevini on Dåno′, an islet off the coast of Guam in the southern Mariana Islands, where for. years it had been considered possibly extirpated. Endemic to the Marianas, E. slevini has declined throughout its range and no longer occurs on as many as five islands from which it was historically known, most likely because of interactions with invasive species and loss of native forest. Our results show that individuals from Dåno′, the type locality for E. slevini, are genetically similar but not identical to E. slevini on Sarigan and Alamagan to the north, and that E. slevini is a close evolutionary relative to another congener in the southern Marianas that is currently recognized as Emoia atrocostata but probably represents an undescribed species in this archipelago. We also show that other, more broadly distributed species of Emoia occurring on Dåno′ are distant relatives to E. slevini and the Mariana lineage of E. atrocostata, providing further evidence of the distinct-iveness of these taxa. The rediscovery of E. slevini on Dåno′ following rodent eradication and culling of a population of monitor lizards suggests that management of invasive species is key to the recovery of this skink in the Mariana Islands, and that a range eclipse on the larger neighbouring island of Guam best explains why the rediscovery took place at the periphery of the species' historic range. A Chamorro abstract can be found in the supplementary material.
Aim
The ‘rate‐of‐living’ theory predicts that life expectancy is a negative function of the rates at which organisms metabolize. According to this theory, factors that accelerate metabolic rates, such as high body temperature and active foraging, lead to organismic ‘wear‐out’. This process reduces life span through an accumulation of biochemical errors and the build‐up of toxic metabolic by‐products. Although the rate‐of‐living theory is a keystone underlying our understanding of life‐history trade‐offs, its validity has been recently questioned. The rate‐of‐living theory has never been tested on a global scale in a phylogenetic framework, or across both endotherms and ectotherms. Here, we test several of its fundamental predictions across the tetrapod tree of life.
Location
Global.
Time period
Present.
Major taxa studied
Land vertebrates.
Methods
Using a dataset spanning the life span data of 4,100 land vertebrate species (2,214 endotherms, 1,886 ectotherms), we performed the most comprehensive test to date of the fundamental predictions underlying the rate‐of‐living theory. We investigated how metabolic rates, and a range of factors generally perceived to be strongly associated with them, relate to longevity.
Results
Our findings did not support the predictions of the rate‐of‐living theory. Basal and field metabolic rates, seasonality, and activity times, as well as reptile body temperatures and foraging ecology, were found to be unrelated to longevity. In contrast, lower longevity across ectotherm species was associated with high environmental temperatures.
Main conclusions
We conclude that the rate‐of‐living theory does not hold true for terrestrial vertebrates, and suggest that life expectancy is driven by selection arising from extrinsic mortality factors. A simple link between metabolic rates, oxidative damage and life span is not supported. Importantly, our findings highlight the potential for rapid warming, resulting from the current increase in global temperatures, to drive accelerated rates of senescence in ectotherms.
Alien predators have on average twice the impact on native prey populations than do native predators, and are a severe threat to wildlife globally. Manipulation experiments can be used to quantify the impact of an alien predator on its prey population/s, but unless the results are compared to benchmarks, it is unclear whether this impact is indeed greater than that of a native predator. Here we use the Australian garden skink Lampropholis delicata and alien black rat Rattus rattus to test if black rats are an additive source of predation for the skink, and to judge whether the effect size of rat-impact on the skink represents that of an alien or native predator. We used replicated experiments to exclude black rats at local and landscape scales to test how rats affect skink activity and trapping frequency. Both manipulations had positive effects on skinks, however, the population-level effect size was lower than that described for alien predators but similar to that expected for native predators. We suggest that Australian skinks may respond appropriately to predatory alien rats because they coevolved with endemic Rattus species. This adds novel insights into the varying levels of impact that alien predators have on native prey.
There is growing concern about mitigation-driven translocations that move animals from anthropogenic threats at donor sites because of their failure rate and lack of application of scientific principles and best practice. We reviewed all known lizard translocations in New Zealand between 1988 and 2013 and identified 85 translocations of 30 lizard taxa to 46 release sites. Most translocations (62%) were motivated by conservation goals for the species or the release site, and one-third were mitigation-driven translocations, typically motivated by habitat loss due to development. Mitigation-driven translocations began in 2003, and since that time have equalled the number of conservation-motivated translocations. Conservation-motivated translocations usually released lizards on islands without mammalian predators, whereas mitigation-driven translocations usually relocated lizards to mainland sites with introduced predators. Long-term monitoring has been sparse and often rudimentary. Eight lizard translocations have recorded population growth, including one mitigation-driven translocation that was into a fenced reserve. Research on commonly used management techniques to mitigate human-related impacts is recommended to establish whether these techniques benefit lizards in the long term.
The two volumes of this handbook provide a comprehensive account of the emerging and vibrant science of the ecological restoration of both habitats and species. Ecological restoration aims to achieve complete structural and functional, self-maintaining biological integrity following disturbance. In practice, any theoretical model is modified by a number of economic, social and ecological constraints. Consequently, material that might be considered as rehabilitation, enhancement, re-construction or re-creation is also included. Principles of Restoration defines the underlying principles of restoration ecology, in relation to manipulations and management of the biological, geophysical and chemical framework. The accompanying volume, Restoration in Practice, provides details of state-of-the-art restoration practice in a range of biomes within terrestrial and aquatic ecosystems. The Handbook of Ecological Restoration will be an invaluable resource to anyone concerned with the restoration, rehabilitation, enhancement or creation of habitats in aquatic or terrestrial systems, throughout the world.
The rare Mercury Islands tusked weta, Motuweta isolata (Orthoptera: Anostostomatidae), a large flightless insect originally confined to 13 ha Middle Island in the Mercury Islands, New Zealand, was last seen there in January 2001. Half-grown or larger insects from a captive-breeding programme were released onto nearby Red Mercury Island (34 ♀, 16 ♂) and Double Island (65 ♀, 19 ♂) in 2000 and 2001 to reduce the potential for accidental extinction. Most (108) were released under individual artificial cover objects (ACOs)-clear Perspex discs under plastic plant-pot saucers- and 26 were placed in artificial holes in soil. Usually <10% were found again under ACOs for up to 18 months including 7.5 months as adults. Adults, found in 2005 and 2006, were 1st to 3rd generation island-bred weta (lifespan 1.7-3.2 years). Ongoing monitoring is planned to confirm long-term success. Inbreeding depression is likely so supplementation from Middle Island is required but they may be extinct there. Scraping the soil to expose weta in underground galleries was the best monitoring method. Few were found by searching with lights at night but adults could be located by following other adults equipped with harmonic radar transponders or micro-transmitters.
Aim
The origins of islands influence island colonization and radiation dynamics, thus exerting differential selection pressures on the species that inhabit them. The occurrence of lower numbers of predator and competitor species on islands than the mainland selects for ‘slow’ life‐history attributes (the ‘island syndrome’). Animals colonizing, and radiating on, oceanic islands probably face more novel environments than do those inhabiting continental fragment and land‐bridge islands. We hypothesized that oceanic island endemics will show the slowest life histories, whereas land‐bridge island species will resemble mainland species the most. We predicted that species on old, small and isolated islands will also have slow life histories.
Location
World‐wide.
Methods
We assembled life‐history data for 540 mainland and 319 insular endemic lizard species. We tested whether clutch size, brood frequency, hatchling mass and productivity differed between islands of different origin and between islands and the mainland. We controlled for female size, for latitude and for phylogenetic relationship using the R package caper . In addition, we tested the influences of island age, area and isolation on species life histories.
Results
Oceanic island endemics have the smallest clutches and the largest offspring, and, together with continental fragment island endemics, lay most frequently. Clutch size, brood frequency and productivity increase with increasing island age. Isolation and area have little effect on lizard life history.
Main conclusions
Our findings support the proposition that selection pressure differs across island type. The predator‐poor environments on oceanic islands select for few, large offspring, while the predator‐rich environments of the mainland and land‐bridge islands select for many, small offspring. Island geological origin creates the environment within which evolution takes place, and thus plays a major role in life‐history evolution. As islands grow older, lizards adapt by increasing their yearly reproductive effort.
We completed a taxonomic revision for the New Zealand Copper Skink (Cyclodina aenea) species complex using morphological and molecular data. Two new species are described on the basis of several morphological characteristics, with the specific status of each species supported by mitochondrial sequence data (ND2). We also redescribe C. aenea. One of the new species is restricted to the Poor Knights Islands, whereas the distribution of the other new species is limited to northernmost region of Northland. Both new species exhibit significant genetic divergence from C. aenea (,13.5% sequence divergence), indicating that each species has evolved in isolation from C. aenea for a substantial period of time.
This paper summarises evidence for low rates of annual reproductive output (no. of offspring or eggs/female/yr) in New Zealand reptiles. Tuatara (Sphenodon spp.) and the geckos Hoplodactylus maculatus and H. duvaucelii are cold‐adapted, nocturnal, and long‐lived, with evidence in at least some populations of less‐than‐annual reproduction. Annual reproductive output estimated for three tuatara populations ranges from 1.27 to 2.28 eggs/ female/yr. New Zealand geckos produce ≤2 offspring/female/yr. Hoplodactylus maculatus in the Macraes‐Middlemarch region of Central Otago produces only about 0.85 offspring/female/yr, as a consequence of biennial reproduction and clutch sizes that are often less than two. The diurnal skinks Leiolopisma grande and L. otagense from the same region breed annually and have larger clutch sizes, so their annual reproductive output is higher (2.17 and 2.34 offspring/female/yr, respectively). Other wild populations of New Zealand skinks typically produce 1–5 offspring/female/yr. Unlike many species of oviparous geckos overseas, the viviparous New Zealand geckos do not produce multiple clutches per year, and this contributes to relatively low annual reproductive output in some species. Viviparous New Zealand skinks have similar annual reproductive output to viviparous skinks of similar body size from other parts of the world. Low annual reproductive output in New Zealand lizards thus appears to reflect, in part, responses to cool summer temperatures in association with a viviparous reproductive mode (geckos), as well as phylogenetic effects (colonisation by lineages of small clutch and body size, in geckos and skinks).
Six priorities are identified for the future management of New Zealandís biological diversity: developing a broader understanding of what the nationís biodiversity includes, involving a wider sector of society in protecting biodiversity, adopting a genuine ecosystem approach to its management, intensifying the effort to control invasive species, increasing the rigour of restoration programmes, and changing attitudes towards use of scientific research in solving biodiversity problems. Opportunities to increase options within these priorities are discussed.
Over the past 20 years, management of many new Zealand islands has been biased towards the well-being of animals rather than plants. The need exits for an equal emphasis on plant and animal ecology in island management - in fact for a single emphasis on the well-being of the whole biota. Island botanical values are reviewed. We propose a fundamental strategy of minimal interference for island management.
With the great potential for deleterious effects, it is difficult to recommend translocations under most conditions. If extant populations exist, protection and habitat improvement are safer and probably more viable alternatives. Translocation of early developmental stages (egs, larvae, neonates) may offer the greatest margin of success in such programs involving amphibians and reptiles. -from Author
Reviews information on relocations, repatriations, and translocations (RRT) projects involving amphibians and reptiles, examines the motives for advocating RRT strategies, and recommends biological and management criteria that should be considered prior to undertaking RRT projects. Most projects involving amphibians and reptiles have not demonstrated success as conservation techniques and should not be advocated as if they are acceptable management and mitigation practices. -from Authors
We summarise the magnitude of New Zealand's species conservation problems, seek a guiding philosophy from which to approach these problems, outline several ways by which species can be treated in a conservation context, and examine various approaches to species-oriented conservation. Using definitions in the Conservation Act 1987 we derive a goal statement for species conservation aimed at placing species into an ecological context: “to present species because of their role as part of a system of interacting organisms and their environment.” We suggest that the Department of Conservation mission statement “to conserve the natural (and historic) heritage of New Zealand for the benefit of present and future generations” be extended by “taking account of the processes that gave rise to and will perpetuate that heritage” and that this more dynamic statement become the explicit guiding philosophy for the Department's species conservation programmes. Public support for the huge task of conserving over 600 threatened species could be helped by viewing species as conservation units (target species and flagship species) as distinct from biological units (indicator species, keystone species and species guilds). To meet the looming crisis over expanding numbers of critically threatened species and finite resources and to improve cost-effective use of conservation funds, we suggest: (i) taking a strategic view of the species conundrum by developing long-term goals based upon an explicit guiding philosophy; (ii) complementing the ranking process with a triage analysis to identify species that cannot at present survive in the wild within their natural range, and seeking short-term solutions in preference to expensive in situ management for these “hopeless” cases; and (iii) viewing community restoration and habitat protection as complementary, not alternative, approaches to target species conservation. We provide a conservation strategy for kakapo as an example of our suggested approach.
Discussion between relevant agencies is underway on plans for a reintroduction of the endangered tortoise Gopherus flavomarginatus from Mexico into Big Bend National Park, Texas, and for the captive-bred offspring of the world's rarest tortoise Geochelone yniphora to be used for both an introduction into entirely new habitat and to bolster extant populations. Several re-introductions are also being planned for Sphenodon guntheri. Relevant literature for the species under consideration should be reviewed, and the potential for success of such translocations should be considered in a cost/benefit or risk analysis. -from Author
A herpetological survey in January 1988 of North Brother Island, Cook Strait, New Zealand, found populations of the tuatara (Sphenodon guntheri) and three species of lizards (Hoplodactylus duvaucelii, Hoplodactylus maculatus, and Leiolopisma lineoocellatum). Tuatara on North Brother I. are significantly smaller than Sphenodon punctatus on nearby Stephens Island, and the estimated density of 134/ha in good habitat is lower than reported on Stephens I. The total adult population size of tuatara is estimated at
Middle Island is unusual for a northern New Zealand island in that it lacks recent human modification and is rat-free. Observations and plant records are compared with Atkinson's botanical survey of the island 21 years earlier. Regeneration in a recent wind-throw area, milk tree (Streblus hanksii) forest age, and weed status are discussed. Ninety-six vascular plant species are recorded in an appended annotated species list for the island and three associated islets; over 70% of these records are vouchered. A bryophyte list of 11 species is included in the Appendix.
The phylogenetic relationships of the Australian scincid lizards currently assigned to the genus Leiolopisma have been examined by quantitative micro-complement fixation (MC'F) comparisons of serum albumin. The results of these comparisons do not support the monophyly implicit in these species' current congeneric status, but suggest instead that the Australian species of Leiolopisma belong to several distinct phyletic lineages within the Eugongylus group. These findings are supported by several sets of non-biochemical characters, including features of scalation, osteology and karyotype. None of the Australian species shares a close relationship with the type-species of Leiolopisrna (L. telfairii), and so a new taxonomic arrangement is proposed which distributes them among the following genera: Bartleia, gen. nov. (jigurru); Bassiana, gen. nov. (duperreyi, platynotum and trilineata); Cautula, gen. nov. (zia); Niveoscincus, gen. nov. (coventryi, greeni, metallicus, microlepidotus, ocellatus, orocryptus, palfreymani and pretiosus); and Pseudemoia Fuhn, 1967 (baudini, entrecasteauxii Group 1; entrecasteauxii Group 2, rawlinsoni and spenceri). Preliminary comparisons suggest that other Leiolopisma species, from New Caledonia, Lord Howe I. and New Zealand, belong to phyletic lineages which are distinct from any of the Australian 'Leiolopisrna' and from the type-species.
By determining the microclimates that an animal experiences, habitats influence an animal's physiological capacities and ultimately its demographic and ecological performance. As a result, the ecology of organisms-especially of ectotherms-can be profoundly affected by the physiological consequences of habitat selection. Early ecologists such as Shelford and Chapman appreciated these issues, but most later ones tended to ignore physiology and instead focused on biotic interactions (e.g., competition). Recent technical and conceptual developments are now fostering a reintroduction of physiology into ecology. For issues relevant to thermal physiology, three steps are involved. First, the microclimates available in a habitat must be mapped. For ectotherms, this involves determining the operative environmental temperatures (Te)-that is, the potential body temperatures available in a habitat. Biophysical techniques can now generate Te maps with considerable accuracy. Second, the physiological effects of body temperature must be quantified. This requires laboratory studies of the effect of temperature on key performance traits. Third, the physiological suitability of habitats can be predicted by integrating the above environmental and physiological data. Analyses of the physiological consequences of habitat selection are exemplified in several case studies, and the importance of considering food and other factors in the analyses is stressed. An extension to endotherms is briefly discussed.
Wild Gopherus agassizii populations have dominance hierarchies, possibly related to defense of such resources as burrows, mates and nests. Tortoises know locations of burrows, mates, water catchments, and mineral licks within their home ranges (1-268 ha). They may take excursions outside customary activity areas and make long-distance movements of 1.4-7.3 km of 16 days to 5 yr duration. Relocated tortoises may settle at release sites, travel in straight lines (Type II navigation), and disperse distances of = or >6.6 km. Areas to be restocked should be at least 14 km in diameter to permit dispersal of relocatees. Relocated tortoises may disrupt the social structure of resident populations by displacing residents, or they may be driven away by residents.-from Author
This is the third edition of a successful textbook, now with material added to illustrate the potential of computers for biologists. It is a lucid introduction to the principles and more elementary techniques of statistical reasoning, particularly as they are relevant to the biologist. Special attention is paid to the validity and use of statistical procedures, the interpretation of results, and the meanings of the conclusions which can then be drawn. The understanding of statistical methods is aided by full explanations of how calculations are built up. A particular feature of this edition is the inclusion, of new material to demonstrate the potential usefulness of computers in biological statistical analysis and to this end computer analyses of a selection of the examples are presented, using several different statistical languages. The examples are designed to guide and encourage the biologist to pursue the use of these languages further. The book assumes no mathematical training and uses a minimum of jargon and symbolism. It will be useful to any biologist, student or research worker who needs an introduction to statistical procedures.
Radiography has been used to determine the proportion of female tuatara that carry eggs each season on Stephens and Lady Alice Islands, New Zealand. The smallest female found to be gravid was 179 mm SVL. Mean clutch size for Lady Alice was 6.4 (range 5-8) and for Stephens 10.8 (range 5-18). A significant positive correlation exists between clutch size and adult female body size on Stephens but not on Lady Alice Island. -from Authors
Influences contributing to the restricted distribution and low numbers of the 3 species are outlined and each species' status and future prospects for conservation are discussed. -from Author
The Pacific Island herpetofauna has primarily Oriental and Gondwanan origins, with recent arrivals derived mainly from the Papuan region. New Zealand and Fiji represent amphibian outposts but some lizard species extend from the Solomons to French Polynesia. Tectonic movements along the Pacific/Australo-Indian plate boundary help explain the anomalous present-day distribution of older elements. Lowering of sea level during ice ages has facilitated rapid W-E spread of a number of recently-arrived gekkonid and scincid species and genera from the Papuan region. New Zealand and New Caledonia are very old island groups with almost exclusively Gondwanan herpetofaunas and very high endemism. The Solomons and Fiji also show considerable island endemis. All reptile species present in French Polynesia are cosmopolitan and apparently recent in origin. Though vicariance mechanisms have contributed to the spread of reptiles and amphibians in the Pacific, sea water gaps have always existed between different archipelagos. The success of reptiles and amphibians in crossing such gaps and in colonising oceanic islands has depended on a number of mechanisms, eg terrestrial eggs (frogs), parthenogenesis and eggs resistant to desiccation (geckos), long incubation periods, continuous breeding and, possibly, long gestation periods and sperm storage. Island populations of animals are usually founded by small numbers of individuals. When there may be rapid divergence from parental populations. A model of speciation is presented for Brachylophus iguanas.-from Author
For some species present-day distributions are relictual because of recent local extinctions, particularly on the mainland. Ecological divergence and species diversity of lizards within selected biogeographic elements are described and compared with ecological and morphological divergence found New Zealand wide. Genetic relationships of some identifiable species groups are examined using data from liver and muscle allozymes. These suggest older lineage divergence events than previously assumed, the biogeographic implications of which are discussed. -from Authors
The technique used was designed to monitor its own progress, kill every rat as quickly as possible, continually detect the presence of surviving rats, limit the risk to non-target species, and overcome the many problems often associated with "getting the last rat'. -from Authors
The distribution patterns of terrestrial animals and plants in Tasmania and the Bass Strait area are of great interest, for disjunctions of range can be dated and may help to reveal something of the environmental conditions prevailing at the time of isolation. Parsons(1969, 1970) has shown there are disjunctions of plant species that can be correlated with sea level (and climatic) changes in the last Pleistocene glacial period (the Late Wisconsin) in south-eastern South Australia, in the Eyre and Yorke Peninsulas and on Kangaroo Island, and in south-western Western Australia. Thus the value of studies on Tasmanian and Bass Strait island animals and plants is increased if they also occur in these areas. Of the terrestrial vertebrates, only the reptiles can throw much light on historical biogeography, for almost every southern Australian island has a reasonably large reptile fauna, and there are disjunctions between the southeastern and south-western temperate areas. On the other hand, only the largest islands have amphibians, the mammals are poorly represented and appear to have suffered many extinctions (Spencer & Kershaw, 1910), and the birds are highly vagile, the present island avifaunas probably resulting from many invasions and colonizations since the end of the Late Wisconsin glacial.
Ecological restoration is defined as active intervention and management to restore biotic communities that were formerly present at a particular place and time. Examples are given from both New Zealand and overseas of a variety of different restoration projects. The possibility is raised of replacing some animal species extinct in New Zealand with related living forms from other countries. Ecological restoration is a means of restoring biological diversity to depleted landscapes and, as a consequence, can increase the variety of ways in which people appreciate nature. Ecological restoration of lost biotic communities should be seen as complementary to the protection of those remaining; both activities are needed in a comprehensive approach to nature conservation. -from Author
The effects of weather on the aboveground, largely nocturnal activity of the tuatara, Sphenodon punctatus, on Stephens Island were investigated between May 1974 and April 1975. The nocturnal geckos Hoplodactylus maculatus and H. stephensi and conspicuous invertebrates were studied at the same time, though in less detail. As expected for an ectotherm, the tuatara is primarily influenced by environmental temperature, although other weather variables have an effect. There is a complex interplay of current and recent past weather conditions, habitat, season, the occurrence of seabirds, and the age and sex of the animals observed. The effects of climate can be masked by other factors. The patterns of nocturnal emergence of the tuatara appear to be well adapted to those of its primary prey (large invertebrates), and extraordinarily similar also to those of the geckos, though these behave differently. Contrary to popular opinion, the tuatara does not hibernate.
Predation by kiore (Rattus exulans) has long been assumed to reduce the abundance and species diversity of lizards on islands around New Zealand. However, proof of this is hard to find, partly because it is difficult to compare lizard populations on different islands. In this paper I review methods for obtaining contemporaneous samples of lizard populations, compare the relative abundances of lizards on islands with and without kiore, and describe the responses of lizard populations to the eradication of kiore. On islands in the Mercury Group, northern New Zealand, kiore are absent from Middle I., present on Stanley I., and formerly present (now eradicated) from Korapuki I. Comparison of islands with kiore versus those without kiore shows that there are differences in addition to those of species richness of lizards. On Middle I. in 1986 and 1987, 65% of the lizard biomass comprised nocturnal/crepuscular species, whereas these species represented only 2% of the biomass on Korapuki I. The circumstantial differences between islands were tested before and after eradication of the kiore from Korapuki I. In the forested parts of this island some lizard species cannot coexist with kiore, and lizard populations in forest changed little in the three years following removal of rats. In coastal areas, however, habitat structure influences vulnerability of lizards to kiore, so removal of rats produced rapid changes in habitat use, population structure and productivity of some lizards. The data indicate that the effects of kiore depend on the size of the island, the extent of modification of habitat, and the availability of habitat refuges. A model presenting a series of hypotheses on the effects of kiore on the terrestrial reptiles of New Zealand islands is presented.
The flora, vegetation, and soils of the two smallest Mercury Islands are described. These islands are lacking in land mammals and the vegetation, although not necessarily unaltered by Polynesians, appears to have been little disturbed for a considerable length of time. The very high phosphorus levels found in the soils arc attributed to the large numbers of burrowing petrels present. Stands of milk tree (Paratrophis banksii) on Middle Island appear to be unique and there are several other unusual features of the vegetation and soils that are not understood. The importance of these islands as places to study the dynamics of coastal vegetation in the absence of rats is stressed.
This paper summarises evidence for low rates of annual reproductive output (no. of offspring or eggs/female/yr) in New Zealand reptiles. Tuatara (Sphenodon spp.) and the geckos Hoplodactylus maculatus and H. duvaucelii are cold‐adapted, nocturnal, and long‐lived, with evidence in at least some populations of less‐than‐annual reproduction. Annual reproductive output estimated for three tuatara populations ranges from 1.27 to 2.28 eggs/ female/yr. New Zealand geckos produce ≤2 offspring/female/yr. Hoplodactylus maculatus in the Macraes‐Middlemarch region of Central Otago produces only about 0.85 offspring/female/yr, as a consequence of biennial reproduction and clutch sizes that are often less than two. The diurnal skinks Leiolopisma grande and L. otagense from the same region breed annually and have larger clutch sizes, so their annual reproductive output is higher (2.17 and 2.34 offspring/female/yr, respectively). Other wild populations of New Zealand skinks typically produce 1–5 offspring/female/yr. Unlike many species of oviparous geckos overseas, the viviparous New Zealand geckos do not produce multiple clutches per year, and this contributes to relatively low annual reproductive output in some species. Viviparous New Zealand skinks have similar annual reproductive output to viviparous skinks of similar body size from other parts of the world. Low annual reproductive output in New Zealand lizards thus appears to reflect, in part, responses to cool summer temperatures in association with a viviparous reproductive mode (geckos), as well as phylogenetic effects (colonisation by lineages of small clutch and body size, in geckos and skinks).
Among introduced passeriform and columbiform birds of the six major Hawaiian islands, some species (including most of those introduced early) may have an intrinsically high probability of successful invasion, whereas others (including many of those introduced from 1990 through 1936) may be intrinsically less likely to succeed. This hypothesis accords well with the observation that, of the 41 species introduced on more than one of the Hawaiian islands, all but four either succeeded everywhere they were introduced or failed everywhere they were introduced, no matter what other species or how many other species were present. Other hypotheses, including competitive ones, are possible. However, most other patterns that have been claimed to support the hypothesis that competitive interactions have been key to which species survived are ambiguous. We propose that the following patterns are true: (1) Extinction rate as a function of number of species present (S) is not better fit by addition of an S2 term. (2) Bill-length differences between pairs of species that invaded together may tend to be less for pairs in which at least one species became extinct, but the result is easily changed by use of one reasonable set of conventions rather than another. In any event, the relationship of bill-length differences to resource overlap has not been established for these species. (3) Surviving forest passeriforms on Oahu may be overdispersed in morphological space, although the species pool used to construct the space may not have been the correct one. (4) Densities of surviving species on species-poor islands have not been shown to exceed those on species-rich islands.
A theory of competitive interaction predicts that ecologically dissimilar species of animals within a taxon occur together on islands more frequently than do ecologically similar species. The theory was tested with rodents of the genera Microtus, Clethrionomys, Peromyscus, and Apodemus. Based upon information derived from mainland studies, the prediction was made that Microtus and Clethrionomys, deemed to be the most similar pair ecologically, occur together on islands rarely. Data from three groups of islands showed the prediction to be correct. These two genera do not occur together on any of the islands examined which support only two genera. Other factors which might govern the observed distributions, including the dispersal abilities of the genera, are discussed. It is suggested that there is a trend in the occupation of islands from ecological generalists to specialists.
Recapture of marked individuals gave estimates of minimum longevity in the field ranging from 7-17 yr (mean 12.7). -from Authors
The study of bone rings in the phalanges and femurs of tuatara (Sphenodon punctatus) from Stephens and Lady Alice islands suggests that the rings form annually. This being so, tuatara reach sexual maturity at between nine and 13 yr of age, depending upon individuals and populations. Growth rate appears to increase with temperature. The growth of phalanges apparently ceases at 15-20 yr in females and at 20-25 yr in males. Rings in femurs are much clearer than those in phalanges and remain discernible up to 35 yr. It is known that tuatara can live 30 yr or more without showing appreciable growth, so their potential longevity exceeds 60 yr. The consequences of these data on knowledge of the structure of tuatara populations are discussed.
Species interactions, as revealed by historical introductions of predators and competitors, affect population densities and sometimes result in extinctions of island reptiles. Mongoose introductions to Pacific islands have diminished the abundance of diurnal lizards and in some cases have led to extinctions. Through these population level effects, biogeographic patterns are produced, such as the reciprocal co-occurrence pattern seen with the tuatara and its predator, the Polynesian rat, and with the tropical gecko competitorsHemidactylus frenatus andLepidodactylus lugubris in urban habitats in the Pacific. Although competition has led to changes in abundance and has caused habitat displacement and reduced colonization success, extinctions of established reptile populations usually occur only as a result of predation.
These introductions, along with many manipulative experiments, demonstrate that present day competition and predation are potent forces shaping community structure and geographic distributions. The human introduction of species to islands can be viewed as an acceleration of the natural processes of range expansion and colonization. The immediate biotic consequences of these natural processes should be of the same intensity as those of the human introductions. Coevolution may subsequently act to ameliorate these interactions and reduce the dynamical response of one species to the other. The role played by coevolution in mediating interactions between competitors and predator and prey is highlighted by the susceptibility of predator-naive endemic species to introduced predators and the invalidity of species-poor communities.
Introduced rats cause extinctions and degrade habitats on islands worldwide; effective countermeasures are overdue. Eradication of Norway rats Rattus norvegicus from a 9-ha island nearby led to a plan to eradicate them from Breaksea Island (170 ha; 354 m a.s.l.), which is forested and rugged. Tracks were cut and 743 bait stations set out. Brodifacoum poison baits laid in May 1988 were checked and replaced daily for 22 days and every few months thereafter for two years. No sign of rats was found during 12 visits between July 1988 and April 1992. The original forest cover is intact and many of the changes caused by rats are reversible. Breaksea Island is now valuable for conservation: native species of birds, lizards and invertebrates have already recolonised unaided or been successfully introduced. With careful planning and adequate resources, rodents could be eradicated from much larger islands.
There is increasing evidence that interspecific competition has set important constraints on the distribution, abundance and evolution of island lizards. This is surprising not because competition is rare but because for a biogeographic pattern caused by species interactions to be detectable, it must be strong enough to override the many physical and historical differences that exist among real islands. Moreover, the direct pairwise links between species, once embedded in the complicated network of species interactions in entire communities, may become diluted and confused by the indirect interactions of still other species, particularly predators. Nevertheless, if competition is strong and if communities are simple (as they are on many species-poor islands), competition leaves its fingerprint on the ecological and evolutionary trajectories taken by island lizards.
Yaws is a chronic, relapsing, non-venereally transmitted disease caused by Treponema pertenue. As a result of the WHO mass treatment campaign of the late 1950s, the prevalence in the Solomon Islands fell dramatically. Here the disease was thought to have been eradicated until an outbreak occurred in 1981. In 1984 a mass treatment survey following modified WHO guidelines was carried out. Subsequent to this campaign, yaws recurred and in 1987 a further treatment survey was required. Two observations were made as a result of our recent experience in controlling yaws in the Solomon Islands. (1) The disease appears to be attenuated. (2) WHO control policy may now be an inappropriate method for dealing with yaws in the Solomon Islands and should be replaced by a method which is integrated into the existing primary health care (PHC) structure.
Biology of Australasian frogs and reptiles. Royal Zoological Society of New South Wales
- R Shine
- H Ehmann
Shine, R.; Ehmann, H. ed. Biology of Australasian frogs and reptiles. Royal Zoological Society of New South Wales. Pp. 7-10.
Eradication campaigns against kiore (Rattus exulans) on Rurima Rocks and Korapuki Island, northern New Zealand. Department of Conservation science and research internal report 97
- I Mcfadden
- D R Towns
McFadden, I.; Towns, D. R. 1991: Eradication campaigns against kiore (Rattus exulans) on Rurima Rocks and Korapuki Island, northern New Zealand. Department of Conservation science and research internal report 97.
An ecological reconnaissance of Korapuki Island, Mercury Islands
- G R F Hicks
- H P Mccoll
- M J Meads
- G S Hardy
- R J Roser
Hicks, G. R. F.; McColl, H. P.; Meads, M. J.; Hardy, G.
S.; Roser, R. J. 1975: An ecological
reconnaissance of Korapuki Island, Mercury
Islands. Notornis 22: 195-220.
The terrestrial reptiles of Australia's island territories. Australian Parks and Wildlife Service special publication 11
- H G Cogger
- R Sadlier
- E Cameron
Cogger, H. G.; Sadlier, R.; Cameron, E. 1983: The
terrestrial reptiles of Australia's island territories.
Australian Parks and Wildlife Service special
publication 11. Canberra, Commonwealth of
Australia.
The ecology and control of rodents in New Zealand nature reserves. New Zealand Department of Lands and Survey information series
- I A E Atkinson
- C Hay
- Ed
Atkinson, I. A. E.; Hay, C. ed. The ecology and
control of rodents in New Zealand nature reserves.
New Zealand Department of Lands and Survey
information series 4: 75-86.
Offshore islands cooperative project with ICI Crop Care Division: Phase Two (Red Mercury Island). Department of Conservation science and research internal report 142
- D R Towns
- I Mcfadden
- P Thomson
- H Robertson
- R Colbourne
Towns, D. R.; McFadden, I.; Thomson, P.; Robertson,
H.; Colbourne, R. 1994: Offshore islands cooperative project with ICI Crop Care Division:
Phase Two (Red Mercury Island). Department of
Conservation science and research internal report
142.