Distribution and status of threatened and endemic marsupials on the offshore islands of south-east Sulawesi, Indonesia

Abstract

We highlight hitherto unreported populations of two globally threatened Phalangeridae species on southeast Sulawesi’s offshore islands – Bear Cuscus Ailurops ursinus and Small Sulawesi Cuscus Strigocuscus celebensis – and observations of a third range-restricted species – Peleng Cuscus Strigocuscus pelengensis. Our data are based on records made during 11 years of seasonal surveys on Buton, and short-term expeditions to Kabaena and Manui. Our observations of S. celebensis on Buton, where it occurs in three protected areas, represent an important range extension for this species, as do our observations of A. ursinus on Kabaena, where it is also widespread. We also report the unexpected presence of S. pelengensis on Manui. Buton in particular appears to be an important stronghold for both A. ursinus and S. celebensis, given that forest ecosystems here remain extensive and relatively intact. Both these species may also display a previously unreported adaptability to disturbed forest and even some non-forest habitats within our study area. Hunting pressures, a proven threat to these species in northern Sulawesi, may also be lesser here.

Full text

Distribution and status of threatened and endemic marsupials
on the offshore islands of south-east Sulawesi, Indonesia
Thomas E. Martin
A,I
, Joseph Monkhouse
A
, Darren P. O’Connell
B
, Kangkuso Analuddin
C
,
Adi Karya
C
, Nancy E. C. Priston
D
, Charlotte A. Palmer
A
, Barnabas Harrison
E
, Jack Baddams
A
,
Abdul H. Mustari
F
, Philip M. Wheeler
G
and David G. Tosh
H
A
Operation Wallacea, Wallace House, Old Bolingbroke, Lincolnshire, PE23 4EX, UK.
B
School of Natural Sciences, Trinity College, Dublin 2, Ireland.
C
Department of Biology, Faculty of Mathematics and Natural Sciences, Halu Oleo University of Kendari,
Southeast Sulawesi, Indonesia.
D
Centre for Ecology, Environment and Conservation, Oxford Brookes University, Gipsy Lane, Oxford,
OX3 0BP, UK.
E
5 Shackleton Court, 2 Maritime Quay, Isle of Dogs, London, E14 3QF, UK.
F
Department of Forest Resources, Conservation, and Ecotourism, Faculty of Forestry, Bogor Agricultural University,
Bogor, Jawa Barat, Indonesia.
G
School of Environment, Earth, and Ecosystem Sciences, Faculty of Science, Technology,
Engineering and Mathematics, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK.
H
Centre for Environmental Data Recording, National Museums of Northern Ireland, 153 Bangor Road,
Holywood, County Down, BT18 OEU, UK.
I
Corresponding author. Email: tom_martin_2010@yahoo.co.uk
Abstract. We highlight hitherto unreported populations of two globally threatened phalangerid species on south-east
Sulawesi’s offshore islands –bear cuscus (Ailurops ursinus) and small Sulawesi cuscus (Strigocuscus celebensis)–and
observations of a third range-restricted species –Peleng cuscus (Strigocuscus pelengensis). Our data are based on records
made during 11 years of seasonal surveys on Buton, and short-term expeditions to Kabaena and Manui. Our observations
of S. celebensis on Buton, where it occurs in three protected areas, represent an important range extension for this species,
as do our observations of A. ursinus on Kabaena, where it is also widespread. We also report the unexpected presence
of S. pelengensis on Manui. Buton, in particular, appears to be an important stronghold for both A. ursinus and S. celebensis,
given that forest ecosystems here remain extensive and relatively intact. Both these species may also display a previously
unreported adaptability to disturbed forest and even some non-forest habitats within our study area. Hunting pressures,
a proven threat to these species in northern Sulawesi, may also be lesser here.
Additional keywords: cuscus, Indonesia, marsupial, Phalangeridae, population.
Received 13 November 2017, accepted 16 February 2018, published online 16 March 2018
Introduction
The biodiversity hotspot of Wallacea, Indonesia, is notable for
its high rate of endemism, particularly in mammals, and its mix
of fauna of both Asian and Australasian origin (Whitten et al.
2002; Myers 2003). Sulawesi, the largest landmass in Wallacea,
represents the westernmost extent of marsupial species in Asia
(Whitten et al.2002), where five members of the Phalangeridae
occur (Helgen and Jackson 2015). Four species are endemic to
Sulawesi and its satellite islands (including the Sula Islands).
The remaining species, the ornate cuscus (Phalanger ornatus), is
found in both far-northern Sulawesi and the Moluccas (Helgen
and Jackson 2015). These endemic Sulawesi cuscuses represent
an important global conservation priority, with one species –
Talaud bear cuscus (Ailurops melanotis)–being considered
Critically Endangered and a top 25 ‘EDGE’species (Flannery and
Helgen 2016; Zoological Society of London 2017), two species –
bear cuscus (Ailurops ursinus) and small Sulawesi cuscus
(Strigocuscus celebensis)–being considered Vulnerable
(Helgen et al.2008; Salas et al.2008), and the final species –
Peleng cuscus (Strigocuscus pelengensis)–being considered
Least Concern, but of very restricted geographic range (Leary
et al.2016a).
The Sulawesi Phalangeridae remain poorly studied (Helgen
and Jackson 2015). Little is known about their ecology, the
Journal compilation Australian Mammal Society 2018 www.publish.csiro.au/journals/am
CSIRO PUBLISHING
Australian Mammalogy
https://doi.org/10.1071/AM17052

threats they face, and even their distribution within Sulawesi
(although see Dwiyahreni et al.1999; Farida and Dahruddin
2008). Here, we report observations of three endemic cuscus
species on south-east Sulawesi’s offshore islands, made during
the course of 13 years of seasonal fieldwork. We highlight
the existence of previously unreported populations of cuscus on
these islands, discuss the apparent status of these populations,
and provide a summary of ecological observations that will
improve existing knowledge of these poorly known marsupials.
Materials and methods
Study area
Fieldwork was focused on three islands off the coast of Sulawesi’s
south-eastern peninsula (Fig. 1): Buton, Kabaena and Manui. We
also briefly visited the islands of Muna and Wowoni.
Buton, located off the mainland’s south-eastern peninsula,
is the largest (~560 000 ha) of Sulawesi’s satellite islands. It is
mostly covered by rugged hills, with a few isolated peaks
reaching up to 1100 m. The island retains much of its original
natural vegetation cover, with 77% of its surface occupied by
forest (Martin et al.2015), and has been highlighted as an area
of high conservation value (Cannon et al.2007). Most of these
forested areas lie within formal protected areas, particularly
the 65 000-ha Lambusango Forest Reserve and the 810-ha
Kakenauwe Forest Reserve in the south of the island, and the
98 600-ha Buton Utara Forest Reserve in the north.
Kabaena, lying west of Buton, is the third-largest (~87 300 ha)
of south-east Sulawesi’s offshore islands. It is more mountainous
than its neighbouring islands, consisting of a single central
massif, Gunung Sambapolulu, which reaches 1560 m (Keim
2009). Forest cover here is patchy –most lowland areas have
been cleared for agricultural land –with pockets of rainforest
remaining in parts of the mountainous interior, along with more
extensive patches of savannah and open woodland (Gillespie
et al.2005). None of these remaining forest patches are formally
protected.
Manui is a small (~9000 ha), low-lying island (maximum
altitude 170 m) that is also the most biogeographically isolated
of south-east Sulawesi’s major satellites, located ~50 km east
of the mainland. It remains very poorly studied. It is covered
mostly in dry monsoon forest (a very different climax vegetation
compared with the seasonal rainforest found on the rest of
south-east Sulawesi’s offshore islands), farmland (primarily
cassava and coconut) and patches of rough scrub. No protected
areas exist on the island.
Muna, the second-largest of south-east Sulawesi’s offshore
islands (~289 000 ha) lies between Buton and Kabaena. It largely
comprises a low-lying (mostly <100 m) limestone plateau,
reaching a maximum elevation of 400 m (Milsom et al.1999).
This relatively flat, easily accessible terrain has led to Muna
being almost entirely deforested and mostly covered with
plantations, arable farmland and scrubland, with only very small
pockets of forest remaining (Gillespie et al.2005). Wowoni
(~650 00 ha) lies north of Buton. Substantial tracts of forest
persist throughout much of the island’s interior (Farida and
Dahruddin 2008); these are predicted to have high conservation
value (Cannon et al.2007), although its ecology remains largely
unexplored.
Survey work
These islands were visited as part of seasonal biodiversity
surveys run by Operation Wallacea (www.opwall.com). These
have run annually between June and August from 1996 to 2017,
with at least one author participating each year between 2004
and 2017 (except in 2015). Most fieldwork has focused on
Buton, which was visited annually for eight weeks between
2004 and 2014. Kabaena was visited in June–July 2016 for
four weeks, Manui was visited in August 2017 for one week,
and Muna and Wowoni were visited in July 2017 for one week
and two weeks respectively. Fieldwork on Buton, Kabaena and
Manui encompassed a range of forest and non-forest habitat,
while on Muna and Wowoni only farmland and scrub habitats
were visited.
No specific survey methodologies were employed to formally
assess cuscus populations on these islands; attempts to do so
failed, largely due to the difficulty of detecting these species
using standardised methodologies. A. ursinus was frequently
observed in the forest and was technically a recordable species
in systematic mammal transect surveys; in practice, however,
these did not produce robust information on the species’
occurrence, with encounters from these surveys averaging <1
observation per season. Fieldwork on Kabaena, Muna, Wowoni,
and Manui was focused specifically towards an evolutionary
study of island birds. Therefore, cuscus observations on all
islands are the result of opportunistic encounters, pooled from
all authors, rather than from formal targeted surveys. To provide
supporting independently verified evidence for our observations,
we archived a research-grade (i.e. independently verified by at
least two other users) image of each cuscus species on each
island where they were observed on inaturalist (inaturalist.org).
Previously existing knowledge of species’distributions was
gathered from range maps produced by the IUCN (Helgen et al.
2008; Salas et al.2008; Leary et al.2016a), and by Helgen and
Jackson (2015), and information provided in Flannery (1995),
Suyanto et al.(2002) and Whitten et al.(2002).
Results
In total, we recorded three cuscus species on three of south-east
Sulawesi’s offshore islands. We discuss these observations in
the species accounts below. Links to our verified records can be
found in Table S1, available as supplementary material to this
paper. A selection of images is provided in Fig. S1.
Bear cuscus (Ailurops ursinus)
A. ursinus was observed on two islands, Buton and Kabaena
(Fig. S1a). It appears to be widespread and fairly common
on Buton, having been observed in three protected areas:
Lambusango Forest Reserve, Kakenauwe Nature Reserve, and
Buton Utara Nature Reserve. It has also been recorded in
multiple habitats, including primary and secondary forest, scrub,
and farmland. This includes one observation in July 2014 of an
individual found in an extensive area of degraded coastal scrub
(531018.900S, 12233055.200 E), with no connectivity to closed-
canopy forest ecosystems. It is difficult to detect within the
forest interior, normally being located high in the canopy.
However, it is often quite conspicuous in forest-edge ecosystems,
where high densities have been recorded. A 2.4-km roadside
BAustralian Mammalogy T. E. Martin et al.

survey detected a maximum of 15 individuals (6.25 individuals
per kilometre walked) in a single count; this was immediately
after an intense rainstorm.
The species was recorded at all three research locations
visited on Kabaena: Sikeli at 10 m (515048.200S, 12147045.200 E),
Enano at 132 m (515047.400 S, 12158008.600 E), and Tangkeno
at 650 m (516043.600S, 12155024.500E), suggesting it to be
widespread on the island. Observations at Enano and Tangkeno
were made in secondary forest, while at Sikeli a single
observation of an adult carrying a juvenile was made within an
(a)
(b)
Manui
Wowoni
Kabaena
Muna
Buton
40 20 0 40
Kilometres
N
Fig. 1. Map showing (a) the location of south-east Sulawesi (inset) within the Indonesian archipelago (total shaded
area), and (b) the locations of the offshore islands of Kabaena, Muna, Buton, Wowoni and Manui in relation to mainland
south-east Sulawesi.
Distribution of marsupials in south-east Sulawesi Australian Mammalogy C

area of highly degraded coastal farmland, with no connectivity
to surrounding forest patches.
In contrast to the findings of Dwiyahreni et al.(1999), who
frequently observed A. ursinus in groups, most of our A. ursinus
sightings on both Buton and Kabaena were of single individuals
or a parent with a juvenile. Sightings of two adults together
were uncommon, and groups of more than three individuals
were observed very rarely.
Small Sulawesi cuscus (Strigocuscus celebensis)
S. celebensis was observed only on Buton (Fig. S1b–d). It is
a cryptic species, given its nocturnal activity cycle (Whitten et al.
2002), and is difficult to survey systematically. Nevertheless,
it was encountered opportunistically relatively frequently,
typically being observed two or three times each field season.
Most observations of this species were at night, with occasional
observations during the day of individuals disturbed by survey
work. These diurnal observations include two incidences of the
species being accidentally disturbed within, and subsequently
emerging from, hollow dead trees. The first of these encounters
involved a single individual observed within a mixed coffee
and cashew plantation (511053.700S, 12250056.700 E) in July
2005, and the second involved an adult and juvenile observed
in closed canopy forest (511048.200S, 12253002.100 E) in July
2007. These records suggest that the species utilises these tree
hollows as sleeping sites during the day, as has been reported for
other nocturnal cuscus species (e.g. Flannery 1995; Salas 2002).
Observations were made throughout much of the island’s
forested area, including within three protected areas:
Lambusango Forest Reserve, Kakenauwe Nature Reserve, and
Buton Utara Nature Reserve. Our observations of S. celebensis
have most frequently been made in closed canopy forest habitats,
although the species has occasionally been encountered in
edge forest, farmland, and within gardens near the city of Ereke
(448057.900S, 12310024.000 E) with no direct connectivity to
large tracts of closed canopy forest.
A further notable observation regarding S. celebensis records
from Buton relates to the variability in the colouration of
individuals. Helgen and Jackson (2015) describe the species as
being a uniform grey-brown colour dorsally, with a white
underbelly, while Flannery (1995) describes it as being drab
brown. On Buton we have observed individuals with dark grey,
grey-brown and sandy-brown dorsal fur (Fig. S1b–d), and some
individuals have a black forehead stripe (Fig. S1b), which is
absent in others (Fig. S1c,d), suggesting that the species’pelage
is more variable than currently described.
Peleng cuscus (Strigocuscus pelengensis)
We recorded S. pelengensis on Manui (Fig. S1e,f), where two
separate individuals were observed on 7 August 2017 within
an extremely rocky, inaccessible area of dry forest growing over
afield of large coral boulders (335043.000S, 12303009.900 E). The
first individual was initially seen in a low bush growing between
these boulders; when disturbed, it crawled into a deep coral hole
and disappeared from view. The second individual was observed
in a tall tree. These individuals were readily distinguished from
S. celebensis by their noticeably larger and more heavily built
bodies, their orange-brown dorsal colouration and yellowish
belly fur, and their wider tail-base (Flannery 1995; Helgen
and Jackson 2015). They also lacked the distinctive dorsal stripe
of the larger-bodied P. ornatus (Flannery 1995; Helgen and
Jackson 2015).
Discussion
The results of our surveys on south-east Sulawesi’s offshore
islands identify important range extensions for all three cuscus
species detected –specifically, A. ursinus on Kabaena,
S. celebensis on Buton, and S. pelengensis on Manui. None of
our consulted sources indicate these species to be previously
recorded on these islands.
While our records of A. ursinus on Kabaena are new, it has
previously been recorded on Buton (Whitten et al.2002; Salas
et al.2008; Helgen and Jackson 2015). We did not record the
species on either Muna or Wowoni, although this might not
be surprising given our very short fieldwork periods on these
islands. It is possible that the species persists on both these
islands, considering its presence on more biogeographically
isolated Buton and Kabaena, and as it has also successfully
colonised the Banggai and Togian Islands in eastern and
northern Sulawesi respectively (Flannery 1995; Salas et al.2008;
Helgen and Jackson 2015). On Muna it is considered to be
a formerly occurring species that may have been extirpated due
to habitat loss (Salas et al.2008). This may or may not be the
case. Small forest fragments remain on Muna that support
large-bodied mammals, such as the booted macaque (Macaca
ochreata) and the Sulawesi wild pig (Sus celebensis). These may
be sufficient to sustain a persistent population of A. ursinus,
given that the species appears to have some tolerance of non-
forest habitats on neighbouring islands (see below). It seems
likely that the species also occurs on Wowoni, given its relative
proximity to the mainland, the large tracts of forest ecosystems
remaining here, and because other cuscus species have been
shown to occur (Farida and Dahruddin 2008).
The fact that S. celebensis has not been previously reported
on Buton is somewhat surprising, given that the island has one
of the most extensive areas of suitable habitat for the species
anywhere in south-east Sulawesi. Our records of the species’
presence in three reserves found on the island also partially
address a knowledge gap identified by Helgen et al.(2008)
regarding protected areas known to support this species.
Although we did not record S. celebensis elsewhere, Farida
and Dahruddin (2008) detected the species on Wowoni, an
important extension to the species’known range that has yet to
be incorporated into distribution maps.
Our records of S. pelengensis on Manui were unexpected,
given that the species is currently recorded only from the
Banggai and Sula islands, some 210 km to the north (Suyanto
et al.2002; Helgen and Jackson 2015; Leary et al.2016a). It is
unclear whether these individuals represent an established
population and whether they are from a natural colonisation
or anthropogenic introduction. In support of these being an
established, natural colonisation, the closely related S. celebensis
has colonised remote islands in north Sulawesi, apparently
naturally, albeit from mainland populations (Helgen and
Jackson 2015), and in the Sula islands S. pelengensis is recorded
from open dry forest, secondary habitats, farmland and scrub,
DAustralian Mammalogy T. E. Martin et al.

matching the habitats that dominate Manui (Flannery 1995;
Helgen and Jackson 2015).
Not only do south-east Sulawesi’s offshore islands support
populations of endemic cuscuses, but they may also represent
particularly important conservation areas for these species.
Buton, in particular, still supports nearly 350 000 ha of lowland
tropical forest, 65% of which lies within official protected areas
and much of which is considered to have high conservation
value (Cannon et al.2007; Martin et al.2015). Therefore, on
Buton at least, large tracts of suitable habitat remain for both
A. ursinus and S. celebensis –an important refuge given rapid
habitat loss elsewhere in their range (Helgen et al.2008; Salas
et al.2008; Helgen and Jackson 2015).
Additionally, our observations also indicate that all three
cuscus species recorded are capable of utilising, at least to
a certain degree, degraded forest, scrub, farmland and garden
habitats, in some cases where these non-forest habitats have
little or no connectivity to closed canopy forest ecosystems.
Such utilisation has been found for other Sulawesi endemics
(Martin and Blackburn 2010; Gillespie et al.2015), and has
been previously described in S. pelengensis (Helgen and
Jackson 2015) as well as in other cuscus species in New Guinea
(e.g. Leary et al.2016b). However, these patterns have not
been previously reported in A. ursinus and S. celebensis, with
both Salas et al.(2008) and Helgen and Jackson (2015) stating
that these species do not readily use disturbed habitats. Our
results raise the possibility that these species may be more
adaptable to habitat modification than previously thought,
although how optimal these habitats are for these cuscus species,
and the extent to which they are used, remains unclear.
The other important threat to these species –hunting for food
(Helgen et al.2008; Salas et al.2008; Helgen and Jackson 2015)–
may be a lesser concern in south-east Sulawesi compared with
elsewhere. MacKinnon (1979), O’Brien and Kinnaird (1996),
Riley (2002) and Lee et al.(2005) all report that both A. ursinus
and S. celebensis are heavily hunted for food in predominantly
Christian northern Sulawesi. On south-east Sulawesi’s offshore
islands, however, where populations are predominantly Muslim,
hunting pressures may be lower, as consuming cuscus meat is
considered a religious taboo (Lee et al.2005). The minority non-
Muslim communities also do not appear to eat cuscus meat on
Buton, despite not being explicitly constrained by religious
beliefs (Priston 2005). Support for the suggestion that hunting
pressure is lower is indirectly provided by the fact that, in the
course of our cumulative 13 field seasons in the region, we have
never observed cuscus being actively hunted, or sold in a market,
as a source of food on any of our study islands. Community
interview data presented in previous research (Priston 2005;
Hardwick et al.2017) also indicate that, unlike pigs and
macaques, farmers on Buton do not consider cuscuses to be
significant crop raiders, and they are not persecuted. Care should,
however, be taken when interpreting the results of these
interviews, given that participants may have provided responses
they believe to be appropriate when discussing conservation
issues, rather than reporting the truth (Hardwick et al.2017).
Nevertheless, people on Buton have frequently told us in
conversation that they have hunted or otherwise persecuted
several threatened and protected species on the island, including
the lowland anoa (B ubalus depressicornis), maleo (Macrocephalon
maleo) and booted macaque (Priston 2005; DGT and PMW,
pers. obs.) but never any cuscus species. Rare second-hand
accounts exist of A. ursinus being captured and kept as pets
on Buton and Kabaena (although none of the authors have
personally observed this). It is perhaps possible that a hypothetical
lower hunting pressure on cuscus in our study area may also help
explain their presence in a range of non-forest habitats here,
afinding that has not been reported elsewhere. It could be that in
northern Sulawesi (where most previous field data for these
species have been sourced), cuscus are principally found in forest
habitats as hunting has extirpated them from other, more open,
habitats where they are more conspicuous and easily harvested,
not because they are intrinsically ecologically dependent on
these forest habitats. However, although we have never observed
evidence of hunting, we cannot be sure this never occurs
without completing targeted surveys, as conducted by Lee et al.
(2005). All cuscus species in south-east Sulawesi breed
slowly, typically raising a single offspring at a time, which
takes several years to reach maturity (Helgen and Jackson 2015).
Thus, even a low or moderate level of hunting pressure that
remained undetected during our fieldwork might still exert
a substantial influence on their demography.
In summary, our findings suggest that the islands of south-east
Sulawesi are likely to represent important strongholds for at
least two of the region’s endemic cuscuses, supporting large
areas of habitat and potentially experiencing lesser hunting
pressures than reported elsewhere in these species’ranges.
Conflicts of interest
The authors declare no conflicts of interest.
Acknowledgements
This project was supported by Operation Wallacea. We thank the Indonesian
Institute of Sciences (LIPI) and Kementerian Riset dan Teknologi Republik
Indonesia (RISTEK) for providing a series of permits for 2004–2014
fieldwork on Buton, and permits 174/SIP/FRP/E5/Dit.KI/V/2016 and 160/
SIP/FRP/E5/Fit.KIVII/2017 for all other islands. We also thank David Kelly,
Nicola Marples, Vivien Cumming, and two anonymous reviewers for their
constructive and helpful comments.
References
Cannon, C. H., Summers, M., Harting, J. R., and Kessler, P. J. A. (2007).
Developing conservation priorities based on forest type, condition, and
threats in a poorly known ecoregion: Sulawesi, Indonesia. Biotropica 39,
747–759. doi:10.1111/j.1744-7429.2007.00323.x
Dwiyahreni, A. A., Kinnaird, M. F., O’Brien, T. G., Supriatna, J., and
Andayani, N. (1999). Diet and activity of the bear cuscus, Ailurops
ursinus, in north Sulawesi, Indonesia. Journal of Mammalogy 80,
905–912. doi:10.2307/1383259
Farida, W. R., and Dahruddin, H. (2008). The selection of forest plants as
feed resources and nesting site of dwarf cuscus (Strigocuscus celebensis)
and nutrient analysis in Wawonii Island, south-east Sulawesi. Jurnal
Biologi Indonesia 5, 201–210.
Flannery, T. (1995). ‘Mammals of the South-western Pacific and Moluccan
Islands.’(Cornell University Press: Ithaca, NY.)
Flannery, T., and Helgen, K. (2016). Ailurops melanotis. The IUCN Red List
of Threatened Species 2016. Available at: http://www.iucnredlist.org/
details/136218/0 [accessed 2 August 2017].
Distribution of marsupials in south-east Sulawesi Australian Mammalogy E

Gillespie, G., Howard, S., Lockie, D., Scroggie, M., and Boeadi, (2005).
Herpetofaunal richness and community structure of offshore islands
of Sulawesi, Indonesia. Biotropica 37, 279–290. doi:10.1111/j.1744-
7429.2005.00038.x
Gillespie, G. R., Howard, S., Stroud, J. T., Ul-Hassanah, A., Campling, M.,
Lardner, B., Scroggie, M. P., and Kusrini, M. (2015). Responses of
tropical forest herpetofauna to moderate anthropogenic disturbance and
effects of natural habitat variation in Sulawesi, Indonesia. Biological
Conservation 192, 161–173. doi:10.1016/j.biocon.2015.08.034
Hardwick, J., Priston, N. E. C., Martin, T. E., Tosh, D. G., Mustari, A. H., and
Abernethy, K. E. (2017). Community perceptions of the crop-feeding
buton macaque (Macaca ochreata brunnescens): an ethnoprimatological
study on Buton Island, Sulawesi. International Journal of Primatology
38, 1102–1119. doi:10.1007/s10764-017-9999-0
Helgen, K., and Jackson, S. (2015). Family Phalangeridae (cuscuses, brush-
tailed possums and scaly-tailed possum). In ‘Handbook of the Mammals
of the World –Volume 5’. (Eds D. E. Wilson, and R. A. Mittermeier.)
pp. 456–497. (Lynx Edicions: Barcelona.)
Helgen, K., Aplin, K., Dickman, C., and Salas, L. (2008). Strigocuscus
celebensis. The IUCN Red List of Threatened Species 2008. Available at:
http://dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T20890A9234928.en
[accessed 2 August 2017].
Keim, A. P. (2009). New species of pandanus (Pandanaceae) from Kabaena
Island, south east Sulawesi, Indonesia. Reinwardtia 13,13–14.
Leary, T., Singadan, R., Menzies, J., Helgen, K., Allison, A., James, R.,
Flannery, T., Aplin, K., Dickman, C., and Salas, L. (2016a). Strigocuscus
pelengensis. The IUCN Red List of Threatened Species 2016. Available
at: http://www.iucnredlist.org/details/20892/0 [accessed 2 August 2017].
Leary, T., Singadan, R., Menzies, J., Helgen, K., Wright, D., Allison, A.,
Salas, L., and Dickman, C. (2016b). Phalanger gymnotis. The IUCN Red
List of Threatened Species 2016. Available at: http://www.iucnredlist.org/
details/16856/0 [accessed 21 January 2018].
Lee, R. J., Gorog, A. J., Dwiyahreni, A., Siwu, S., Riley, J., Alexander, H.,
Paoli, G. D., and Ramono, W. (2005). Wildlife trade and implications
for law enforcement in Indonesia: a case study from north Sulawesi.
Biological Conservation 123, 477–488. doi:10.1016/j.biocon.2005.01.009
MacKinnon, J. (1979). A glimmer of hope for Sulawesi? Oryx 15,55–59.
doi:10.1017/S0030605300016392
Martin, T. E., and Blackburn, G. A. (2010). Impacts of tropical forest
disturbance upon avifauna on a small island with high endemism:
implications for conservation. Conservation & Society 8, 127–139.
doi:10.4103/0972-4923.68914
Martin, T. E., Harrison, B., and Wheeler, P. M. (2015). The case for REDD+
funding for the forests of Buton Island, SE Sulawesi, Indonesia –
a summary. Operation Wallacea, Old Bolingbroke, UK.
Milsom, J., Ali, J., and Sudarwono, (1999). Structure and collision history
of the Buton continental fragment, eastern Indonesia. AAPG Bulletin 83,
1666–1689.
Myers, N. (2003). Biodiversity hotspots revisited. Bioscience 53, 916–917.
doi:10.1641/0006-3568(2003)053[0916:BHR]2.0.CO;2
O’Brien, T. G., and Kinnaird, M. (1996). Changing populations of birds
and mammals in northern Sulawesi. Oryx 30, 150–156. doi:10.1017/
S0030605300021530
Priston, N. E. C. (2005). Crop-raiding by Macaca ochreata brunnescens
in Sulawesi: reality, perceptions and outcomes for conservation.
Ph.D. Thesis, University of Cambridge, Cambridge.
Riley, J. (2002). Mammals of the Sangihe and Talaud Islands, Indonesia, and
the impact of hunting and habitat loss. Oryx 36, 288–296. doi:10.1017/
S0030605302000510
Salas, L. A. (2002). Comparative ecology and behavior of the mountain
cuscus (Phalanger carmelitae), silky cuscus (Phalanger sericeus)
and coppery ringtail (Pseudochirops cupreus) at Mt. Stolle, Papua New
Guinea. Ph.D. Thesis, University of Massachusetts, Amherst, MA.
Salas, L., Dickman, C., Helgen, K., and Flannery, T. (2008). Ailurops ursinus.
The IUCN Red List of Threatened Species 2008. Available at: http://www.
iucnredlist.org/details/40637/0 [accessed 2 August 2017].
Suyanto, A., Yoneda, M., Maryanto, I., Maharadatunkamsi, and Sugardjito,
J. (2002). ‘Checklist of the Mammals of Indonesia.’(LIPI-JICA-PHKA:
Bogor, Indonesia.)
Whitten, T., Mustafa, M., and Henderson, G. S. (2002). ‘The Ecology of
Sulawesi.’2nd edn. (Gadjah Mada University Press: Yogyakarta.)
Zoological Society of London 2017. EDGE of existence –evolutionary
distinct and globally endangered. Available at: http://www.edgeof
existence.org/mammals/top_100.php [accessed 2 August 2017].
FAustralian Mammalogy T. E. Martin et al.
www.publish.csiro.au/journals/am