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Genomic divergence between Chloephaga poliocephala, and continental and insular populations of C. rubidiceps. (a) A principal coordinates analysis (PCoA) displaying differences at 1706 single nucleotide polymorphisms (SNPs) among C. poliocephala and continental and insular populations of C. rubidiceps (the percentage of variation explained by each axis is in parenthesis). (b) A structure plot derived from 1074 SNPs (one per RAD locus). Individuals marked with arrows have admixture coefficients with 90% Bayesian CI that do not overlap with zero or one. (c) Results from an analysis of molecular variance (AMOVA) showing the distribution of genetic variation; 19.6% of which can be explained by differences among species/populations. (d) Boxplots showing the distribution of F ST values across 1706 SNPs for each pairwise comparison (colour coded). There are three fixed SNPs between C. poliocephala and the continental population of C. rubidiceps, and six fixed SNPs between insular C. rubidiceps and C. poliocephala (superimposed).
Source publication
Aim
The Malvinas/Falkland Islands ( MFI ) constitute the largest archipelago in the southern Atlantic, and harbour endemic lineages that presumably evolved after sea‐level rise, associated with glacial periods, isolated ancestral populations. We investigate the role of the MFI in isolating populations from continental counterparts of two highly vag...
Contexts in source publication
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... potential high vagility of sheldgeese, the insular populations of C. rubidiceps and C. picta leucoptera showed strong evidence of genetic isolation from their respective continental populations. Insular indi- viduals of C. rubidiceps clustered separately from their conti- nental counterparts in a PCoA based on 1706 SNPs sampled across the genome (Fig. 2a), in which C. poliocephala indi- viduals also formed a separate cluster. structure assigned individuals to three different genetic clusters using 1074 ...
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... (one per RAD locus), showing low levels of admixture ( Fig. 2b; see Appendix S2 for overall likelihood and selection of the optimal model sensu Evanno et al., 2005). Approxi- mately 20% of the genetic variation in the C. rubidiceps/C. poliocephala comparison could be explained by differences among populations/species (Fig. 2c). The overall level of genomic differentiation between continental and ...
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... (one per RAD locus), showing low levels of admixture ( Fig. 2b; see Appendix S2 for overall likelihood and selection of the optimal model sensu Evanno et al., 2005). Approxi- mately 20% of the genetic variation in the C. rubidiceps/C. poliocephala comparison could be explained by differences among populations/species (Fig. 2c). The overall level of genomic differentiation between continental and insular pop- ulations of C. rubidiceps was comparable in magnitude to that of either population with their sister species, C. polio- cephala (Fig. 2d). We did not find fixed SNPs between insu- lar and continental populations of C. rubidiceps. There were three fixed ...
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... genetic variation in the C. rubidiceps/C. poliocephala comparison could be explained by differences among populations/species (Fig. 2c). The overall level of genomic differentiation between continental and insular pop- ulations of C. rubidiceps was comparable in magnitude to that of either population with their sister species, C. polio- cephala (Fig. 2d). We did not find fixed SNPs between insu- lar and continental populations of C. rubidiceps. There were three fixed differences between C. poliocephala and continen- tal C. rubidiceps, and six different SNPs were fixed between the former species and insular C. rubidiceps (Fig. ...
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... of either population with their sister species, C. polio- cephala (Fig. 2d). We did not find fixed SNPs between insu- lar and continental populations of C. rubidiceps. There were three fixed differences between C. poliocephala and continen- tal C. rubidiceps, and six different SNPs were fixed between the former species and insular C. rubidiceps (Fig. ...
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... one C. picta leucoptera individual showing evidence of admixture. Subspecies accounted for c. 14% of the genetic variation (Fig. 3c), and we found only one fixed difference (Fig. 3d). The average level of genomic differentiation between subspecies of C. picta was smaller than that found between insular and continental populations of C. rubidiceps (Fig. 3d, cf. Fig. ...
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... is responsible for the low admixture levels inferred by structure. Similarly, continental C. picta picta and insular C. picta leucoptera populations have not experi- enced detectable levels of gene flow. While the latter two populations are considered subspecies, the populations of C. rubidiceps show slightly higher levels of differentiation (Fig. 2d, cf. Fig. 3d) and are not recognized as different tax- onomic units. Based on our results, we suggest that conti- nental and insular populations of the ruddy-headed goose (C. rubidiceps) should be considered different taxa. Differ- ences in morphology, behaviour and ecology have also been suggested between these putatively different taxa (Chebez, ...
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The Carpathians are one of the key biodiversity hotspots in Europe. The mountain chain uplifted during Alpine orogenesis and is characterised by a complex geological history. Its current biodiversity was highly influenced by Pleistocene glaciations. The goal of the current study was to examine the phylogenetic and demographic history of Gammarus ba...
Citations
... The main factors that have promoted the diversification of the Neotropical avifauna include the Andes Mountains (Weir 2006, Brumfield and Edwards 2007, Sedano and Burns 2010, Weir and Price 2011, wide rivers (Ribas et al. 2012, Naka and Brumfield 2018, Kopuchian et al. 2020, Thom et al. 2020) and the closure of the Isthmus of Panama (Weir et al. 2009, Smith andKlicka 2010). Although with a more prominent role in the Northern Hemisphere and the southern extreme of South America, the Pleistocene glacial cycles also played a relevant role as avian diversification drivers throughout the Neotropics (Lessa et al. 2003, Weir and Schluter 2004, Lovette 2005, Campagna et al. 2012, Kopuchian et al. 2016, Acosta et al. 2020, Bukowski et al. 2023. This is clearly the case for highland Andean taxa (Weir 2006, Jetz et al. 2012, but also in the lowlands Pleistocene climatic oscillations have driven speciation by promoting cycles of contraction, fragmentation and expansion of forest ranges, which generated vicariance, divergence and in some cases secondary contact of both forest and dry habitat species (Rull et al. 2011, Trujillo-Arias et al. 2017, Silva et al. 2019, Bolívar-Leguizamón et al. 2020, Thom et al. 2020. ...
The Andean and Atlantic forests are separated by the open vegetation corridor, which acts as a geographic barrier. However, these forests experimented cycles of connection and isolation in the past which shaped the phylogeographic patterns of their biotas. We analyzed the evolutionary history of the Rufous-capped Antshrike (Thamnophilus ruficapillus), a species with a disjunct distribution in the Atlantic and Andean forests and therefore an appropriate model to study the effect of the open vegetation corridor and the Andes on the diversification of the Neotropical avifauna. We performed a phylogenetic/phylogeographic analysis including the five subspecies, using mitochondrial and nuclear genomic DNA, and also studied their differences in vocalizations and plumage coloration. Both the mitochondrial and nuclear DNA evidenced a marked phylogeographic structure with three differentiated lineages that diverged without gene flow in the Pleistocene (1.0-1.7 million years ago): one in the Atlantic Forest and two in the Andean forest. However, the two Andean lineages do not coincide with the two disjunct areas of distribution of the species in the Andes. Vocalizations were significantly different between most subspecies, but their pattern of differentiation was discordant with that of the nuclear and mitochondrial DNA. In fact, there is no song differentiation between the subspecies of the Atlantic Forest and that of the northwestern Bolivian Andes, even though they differ genetically and belong to different lineages. Consistently, no differences were found in plumage coloration between the subspecies of the Atlantic Forest and that of the southern Andes. Our results suggest a complex evolutionary history in this species, which differentiated both due to dispersion across the open vegetation corridor, likely during a period of connection between the Andean and Atlantic forests, and as a consequence of a geographic barrier in northern Bolivia. In both cases Pleistocene climatic oscillations appear to have influenced the species diversification.
... More similarly to the Northern Hemisphere, in Patagonia (the southern extreme of the continent) and in the highland habitats of the Andes, the direct advance of the ice and the expansion of glaciers during Pleistocene glaciations presumably isolated bird populations in refugia (Kopuchian et al., 2016;Weir, 2006) and generated an increase in their diversification rates (Jetz et al., 2012;Weir, 2006). However, southern South America has been comparatively much less studied than the rest of the Neotropics and the diversification processes in the region are still not as clear (Turchetto-Zolet et al., 2013). ...
... Studies performed in plants and vertebrates in Patagonia suggest that diversification patterns in this area were also more complex than in North America and were generated both by glacial cycles and pre-Pleistocene geological factors (Sánchez et al., 2021;Sérsic et al., 2011;Turchetto-Zolet et al., 2013). The effect of glaciations on Patagonian birds has been particularly understudied, but the few analyses performed so far suggest a marked effect of glaciations that affected several species (Acosta et al., 2020;Campagna et al., 2012;Kopuchian et al., 2016). ...
Aim
The Neotropics constitute the most biodiverse region of the world, yet its patterns of diversification and speciation differ among Neotropical areas and are not equally well understood. Particularly, avian evolutionary processes are understudied in the open habitats of temperate South America, where the role of glacial cycles is not clear. We analysed the evolutionary history of a Neotropical widespread bird species as a case study to evaluate its continental‐scale patterns and processes of diversification, with a focus on Patagonia.
Location
Open habitats of the Neotropics.
Taxon
Vanellus chilensis (Aves, Charadriiformes).
Methods
We obtained reduced representation genomic and mitochondrial data from the four subspecies of V. chilensis to perform a phylogenetic/phylogeographical analysis and study the evolutionary history of the species. We complemented these analyses with the study of vocalizations, a reproductive signal in birds.
Results
The initial diversification event within V. chilensis , approximately 600,000 years ago, split a Patagonian lineage from one containing individuals from the rest of the Neotropics. We found considerable gene flow between these two lineages and a contact zone in northern Patagonia, and showed that genomic admixture extends to northwestern Argentina. Shallower divergence was detected between the two non‐Patagonian subspecies, which are separated by the Amazon River. Vocalizations were significantly different between the two main lineages and were intermediate in their temporal and frequency characteristics in the contact zone.
Main Conclusions
Patagonian populations of V. chilensis are clearly differentiated from those of the rest of the Neotropics, possibly as a consequence of Pleistocene glaciations. A secondary contact zone in northern Patagonia with extensive gene flow among lineages appears to be the consequence of post‐glacial, northward expansion of the Patagonian populations. Future analyses focused on the dynamics of the contact zone will allow us to establish whether the species continues to diverge or is homogenizing.
... The ruddy-headed goose, Chloephaga rubidiceps, which is the smallest of the five South American sheldgeese, has two separate populations: one sedentary, which resides in Falkland/Malvinas Islands, and one migratory (the mainland South American population) that overwinters mainly in Southern Buenos Aires province (Pampas region, Central Argentina) and breeds in Southern Patagonia (Argentina and Chile, Fig. 1) (Pedrana et al. 2020). New findings postulated that these two populations are genetically isolated as they do not share mtDNA haplotypes (Bulgarella et al. 2014) and have dissimilarities based on their nuclear DNA (Kopuchian et al. 2016). Still, the IUCN Red List considers the ruddyheaded goose as least concern (BirdLife International 2016) due to the fact that this species has a large global population that is estimated to be 43,000-82,000 individuals (Woods and Woods 2006). ...
Ruddy-headed goose Chloephaga rubidiceps has a migratory population that overwinters mainly in the Pampas region, Argentina, and breeds in Southern Patagonia. This population has decreased considerably, with less than 800 individuals remaining to date. We conducted the first assessment on the influence of environmental and anthropogenic-impact (wind farms and high-voltage networks) variables on ruddy-headed goose migration pathways across the Patagonian coast by applying kernel density analyses and statistical procedures. We used satellite tracking data obtained from six ruddy-headed geese during their migration pathways between 2015 and 2018. Five core distribution areas were identified during migration. During autumn migration, core areas were associated with high primary productivity and low elevation areas, while during spring migration they were located in the proximity of watercourses and waterbodies. We found that more than 30% of the grid cells included in the influence area of high-voltage networks overlapped with high-density areas for ruddy-headed geese during both migrations. Around 30% of the grid cells included in the influence zone of wind farms overlapped with high-density areas for ruddy-headed goose during autumn migration; while this applied to only 13% during spring migration.
We highlight areas of high-risk along the distributional range of the species where large-scale patterns of collision mortality are likely to occur and mitigation measures should be prioritized. We suggest proactive measures that could mitigate future collisions with energy infrastructure because, given their threatened status, a few deaths may have a large effect on the small remnant population.
... La primera de ellas conocida como "malvinera-insular" se localiza en el archipiélago de las Islas Malvinas y presenta hábitos sedentarios. La segunda población conocida como "continental-fueguina" se distribuye en el sector continental de Chile y la Argentina (en las provincias de Tierra del Fuego, Santa Cruz, Chubut, Río Negro, Buenos Aires y, ocasionalmente en La Pampa y Neuquén) y es de hábitos migratorios (Rumboll y Canevari, 1991;Canevari, 1996;Blanco et al., 2001Blanco et al., , 2003aBlanco et al., , 2003bPetracci et al., 2008;Ibáñez y Petracci, 2014;Kopuchian et al., 2016). La información disponible sobre los hábitats utilizados por ambas poblaciones es heterogénea, existiendo más datos para la "malvinera-insular". ...
... Según Woods (2017) en las Islas Malvinas la especie prefiere zonas con pasto corto cercanas a la costa, lagos y lagunas, raramente en las montañas o zonas con pastos más altos. Para algunos autores los individuos de la población del archipiélago de las Islas Malvinas, de tamaño algo menor, coloración más oscura, vocalizaciones distintas, carente de comportamiento migratorio y sometida a un aislamiento genético de 200.000 años, sería otra subespecie (Chebez et al., 2008) o especie diferente (Bulgarella et al., 2014;Kopuchian et al., 2016). En este sentido, estos últimos autores hallaron que las diferencias genéticas entre ambas poblaciones son tan marcadas como las existentes con su congénere el cauquén de cabeza gris. ...
... ejemplares remanentes de la población migratoria "continental-fueguina". Distintos autores han manifestado la necesidad imperiosa de que los criterios utilizados por la UICN sean revisados para esta especie en particular y que dicha categorización sea revaluada, al igual que se implementen acciones urgentes para la conservación de esta población biogeográfica críticamente amenazada Bulgarella et al., 2014;Kopuchian et al., 2016;Cossa et al., 2017;. A mediados del año 2020, el Grupo de Especialistas en Aves Acuáticas Amenazadas de la UICN (Threatened Waterfowl Specialist Group, TWSG por sus siglas en inglés), encargado de identificar los taxones de anseriformes amenazados a nivel mundial, monitorear su estado, producir planes de acción internacionales e intercambiar información sobre proyectos de conservación a nivel mundial realizó un aporte muy significativo para mejorar el contexto de conservación del cauquén colorado. ...
El presente libro “Dos décadas de trabajo con especies amenazadas de la Argentina” consiste en una recopilación y actualización de la información disponible de 26 especies amenazadas de la flora y la fauna argentina. Cada una de ellas es tratada en capítulos desarrollados por investigadores, naturalistas y referentes y contienen la información que se detalla a continuación. El orden en que se presenta cada especie se basa en la clasificación taxonómica.
... Among waterbirds, the Ruddy-headed Goose (Chloephaga rubidiceps) is the smallest of the five South American sheldgeese and has two separate populations: one sedentary, which resides in the Falkland/ Malvinas Islands, and one migratory that overwinters mainly in the Pampas region (Argentina) and breeds in Southern Patagonia (Argentina and Chile) (Pedrana et al. 2020). Recent findings postulated that these two populations are genetically isolated (Bulgarella et al. 2014;Kopuchian et al. 2016). Still, the Ruddy-headed Goose is considered as Least Concern (Birdlife International 2016) by the IUCN Red List because it has a large global population (ca. ...
The Ruddy-headed Goose (Chloephaga rubidiceps) has two separate populations: one sedentary, which resides in the Falkland/Malvinas Islands and one migratory that overwinters mainly in the
Pampas region (Argentina) and breeds in Southern Patagonia (Argentina and Chile). The migratory population has decreased considerably to less than 800 individuals and is categorised as
Endangered in Argentina and Chile. Knowing the dates at which birds leave the wintering grounds might help to predict the arrival date at stopover sites and breeding areas. We aimed to examine
the effect of meteorological conditions on the decision of Ruddy-headed Geese to start spring migration and their migration strategy. We used data from six adults, equipped with satellite
transmitters, over 4 years (2015–2018), giving 12 individual departure dates. Weather conditions on departure dates were compared with that during the 15 preceding days. We tested the influence of
weather conditions on the response variable measured as a comparison of pre-migration dates versus departure dates. Our results showed that Ruddy-headed Geese departure from their
wintering grounds is in association with high wind speed, good visibility and low percentage of cloud cover. The relationship between meteorological conditions and the species decision to start spring migration is essential information for future management plans to prevent potential human-sheldgeese conflicts to escalate along their migration route. Recommendations for the conservation of this species that include implementing mitigation measures to reduce bird collision at human infrastructure, could be applied more specifically during the periods when birds are expected to arrive in each area.
... The Ruddy-headed goose, Chloephaga rubidiceps, which is the smallest of the ve South American sheldgeese, has two separate populations: one sedentary, which resides in Falkland/Malvinas Islands, and one migratory (the mainland South American population) that overwinters mainly in Southern Buenos Aires province (Pampas region, Central Argentina) and breeds in Southern Patagonia (Argentina and Chile, Fig. 1) (Pedrana et al. 2020). New ndings postulated that these two populations are genetically isolated as they do not share mtDNA haplotypes (Bulgarella et al. 2014) and have dissimilarities based on their nuclear DNA (Kopuchian et al. 2016). Still, the IUCN Red List considers the Ruddy-headed goose as least concern (BirdLife International 2016) due to the fact that this species has a large global population that is estimated to be 43,000-82,000 individuals (Woods and Woods 2006). ...
Ruddy-headed goose Chloephaga rubidiceps has a migratory population that overwinters mainly in the Pampas region, Argentina, and breeds in Southern Patagonia. This population has decreased considerably, with less than 800 individuals remaining to date. We conducted the first assessment on the influence of environmental and anthropogenic impact (wind farms and high voltage networks) variables on Ruddy-headed goose migration pathways across the Patagonian coast by applying kernel density analyses and statistical procedures on satellite tracking data obtained from six Ruddy-headed geese during their migration pathways between 2015 and 2018. Five core distribution areas were identified during migration. During autumn migration, core areas were associated with high primary productivity and low elevation areas, while during spring migration they were located in the proximity of watercourses and waterbodies. We found that around 30% of the grid cells included in the high-density areas were located in the influence area of high voltage networks during both migrations. While 33% of the grid cells included in the high-density areas were in the influence zone of wind farms during autumn migration; while this applied to only 13% during spring migration.
We highlight areas of high risk along the distributional range of the species where large-scale patterns of collision mortality are likely to occur and mitigation measures should be prioritized. We suggest proactive measures that could mitigate future collisions with energy infrastructure because, given their threatened status, a few deaths may have a large effect on the small remnant population.
... Migratory sheldgeese (continental Upland Goose Chloephaga picta picta, Ashy-headed Goose Chloephaga poliocephala and continental Ruddy-headed Goose Chloephaga rubidiceps) are endemic to southern South America. The Ruddy-headed and Upland Geese have also separate and genetically distinct sedentary populations in the Malvinas/Falklands Islands (Bulgarella et al. 2013;Kopuchian et al. 2016). At present, the continental, migratory populations are threatened by illegal hunting, overgrazing and invasive predators (Canevari 1996;Madsen et al. 2003;Petracci et al. 2015a). ...
Upland Goose Chloephaga picta, Ashy-headed Goose Chloephaga poliocephala and Ruddy-headed Goose Chloephaga rubidiceps are endemic goose-like threatened birds of southern South America. This work aimed to study how sheldgeese are distributed both temporally and spatially and characterize their habitat use in part of their breeding range in Southern Argentina, a little-explored subpolar region. We conducted nine surveys between spring 2013 and summer 2016 across a maximum of 235 km in Santa Cruz and 698 km in Tierra del Fuego per survey. We recorded the presence of non-breeding sheldgoose groups and Upland Goose pairs. We collected data at site-scale (~ 0.8 km2) and extracted data from geographic information systems for landscape-scale (5 km2) analyses. We recorded 2396 non-breeding groups containing one, two or the three species, 788 Upland Goose pairs and 102 solitary individuals. The Upland Goose was present in almost all groups and was the most abundant sheldgoose, followed by the Ashy-headed Goose. The Ruddy-headed Goose was observed only in 15 locations. Poa grasslands, meadows and Festuca grasslands were the habitats in which we detected most individuals. Sheldgoose density was higher in Tierra del Fuego than in Santa Cruz, and increased from spring to autumn and decreased in winter. The largest sheldgoose groups were concentrated in meadows and waterbodies. Sheldgeese selected sites with greater habitat diversity, habitat richness and number of habitats patches. Our results provide information to understand which environmental conditions favour sheldgeese and to aid in the selection of important areas for the conservation of these species.
... Identifying population genetic structure has become an increasingly important tool for targeted conservation strategies aimed at maintaining historical genetic diversity (Crandall et al. 2000;Frankham et al. 2017). Using population genetic structure to delineate evolutionarily significant units (ESUs; Moritz 1994;Pennock and Dimmick 1997), management units (Taylor and Dizon 1999), or conservation units (Crandall et al. 2000;Kopuchian et al. 2016;Peters et al. 2016) within species allows us to focus resources in a way that conserves the most possible genetic diversity (Frankham et al. 2002). Despite the many definitions of ESUs (Waples 1991;Dizon et al. 1992;Avise 1994;Moritz 1994;Vogler and Desalle 1994;Crandall et al. 2000), reciprocal monophyly in mitochondrial DNA (mtDNA) has long been a standard for avian taxa (Moritz 1994;Zink and Barrowclough 2008). ...
Genetic diversity, population delineation and rates of gene flow can be used to help understand long-term population dynamics, which is important for conserving species with fragmented distributions. Here, we sequenced 19 nuclear introns (nuDNA) and a portion of mitochondrial DNA (mtDNA) across three subspecies of Pacific black ducks (Anas superciliosa ssp.; NmtDNA = 162; NnuDNA = 49) from Australia and surrounding islands in order to measure levels of genetic structure and gene flow. First, despite evidence of gene flow from Australia, Pacific black ducks from the Solomon Islands were significantly differentiated from all other groups in both mtDNA and nuDNA. This is probably due to genetic drift resulting in lowered genetic diversity. We found the lowest levels of genetic differentiation between locations sampled in Australia, suggesting strong connectivity across the continent. Despite elevated differentiation in mtDNA between Australia and other islands (i.e. Timor, New Zealand), low nuDNA divergence suggests some connectivity. Such marker discord is common among waterfowl and is likely due to male-biased dispersal from Australia. Finally, mtDNA of Pacific black ducks from New Zealand showed introgression of haplotypes from feral mallards (A. platyrhynchos), which were established in the 1800s. Overall, these data suggest that A. superciliosa ssp. consist of three distinct genetic units that correspond with subspecies classifications and require individual conservation planning.
... The latest estimate of the mainland population size is between 900 and 1,178 individuals (Blanco et al. 2006). Two recent studies have found that the 2 populations are highly genetically distinct (Bulgarella et al. 2014, Kopuchian et al. 2016, which may warrant a taxonomic revision (Kopuchian et al. 2016). The species is now listed in Argentina as "Critically Endangered" (López-Lanús et al. 2008, Ibáñez andPetracci 2014), yet basic information such as where populations overwinter is lacking, making effective conservation impossible (Cossa et al. 2017). ...
... The latest estimate of the mainland population size is between 900 and 1,178 individuals (Blanco et al. 2006). Two recent studies have found that the 2 populations are highly genetically distinct (Bulgarella et al. 2014, Kopuchian et al. 2016, which may warrant a taxonomic revision (Kopuchian et al. 2016). The species is now listed in Argentina as "Critically Endangered" (López-Lanús et al. 2008, Ibáñez andPetracci 2014), yet basic information such as where populations overwinter is lacking, making effective conservation impossible (Cossa et al. 2017). ...
Although the migration ecology of birds breeding in the Neotropics is still poorly studied relative to that of their counterparts breeding at north-temperate latitudes, studies conducted over the last 2 decades have revealed that migration in the Neotropics is much more common and diverse than previously thought. These studies have identified dozens of species that migrate latitudinally within South America, altitudinally within various mountain ranges, to and between Caribbean islands, and longitudinally across diverse ecosystems such as the Amazon rainforest. Advances in miniaturized tracking technologies, enormous citizen science databases, and powerful analytical approaches provide an unprecedented ability to detect and evaluate temporally and spatially fine-scale patterns, greatly facilitating the study of migratory patterns across tropical regions. We argue that a renewed effort in research on short- and long-distance bird migration within the Neotropics will allow (1) comparative studies that identify the emergent properties of migratory behavior, (2) identification of the convergent or unique mechanistic drivers of migration across diverse ecological settings, (3) formulation of effective conservation and management plans for migratory Neotropical birds, and (4) predictions about how migratory birds will respond to large-scale climatic changes within the Neotropics. Here, we review the current state of knowledge on Neotropical bird migration, with a focus on South America. We specifically examine similarities and differences in the observed migratory patterns of birds that breed in the Nearctic compared to the Neotropics and highlight key future research questions.
... This species has two separate populations: one sedentary, which resides in the Malvinas/Falkland Islands and one migratory population (the mainland South American population) that overwinters mainly in Southern Buenos Aires province (Pampas region, Central Argentina) and breeds in Southern Patagonia (Argentina and Chile). Recently, new findings postulated that these two populations are genetically isolated as they do not share mtDNA haplotypes (Bulgarella et al. 2014) and have dissimilarities based on their nuclear DNA (Kopuchian et al. 2016). However the latest IUCN Red List considered this species as 'Least Concern' (BirdLife International 2016). ...
Ruddy-headed Goose Chloephaga rubidiceps is the smallest of the five South American sheldgeese and has two separate populations: one sedentary, which resides in the Malvinas/Falkland Islands and one migratory that overwinters mainly in the Pampas region, Argentina and breeds in Southern Patagonia. The Ruddy-headed Goose’s continental population has decreased considerably, and recent estimates indicated that the population size is less than 800 individuals. In Argentina and Chile, this population is categorised as endangered. Understanding migration across vast landscapes is essential for the identification of factors affecting the survival of this endangered population and for the application of effective conservation measures. We aim to provide the first documentation of the complete migration cycle of Ruddy-headed Goose, and to analyse their annual migration in detail, including identification of stop-over, breeding and wintering sites, and to compare migration timing during spring and autumn migration. Adults were captured in the southern Pampas and equipped with solar satellite transmitters in 2015 and 2016. We analysed the influence of season (spring vs autumn migration) on the number and duration of stop-overs, distance travelled and overall migration speed using Generalized Linear Mixed Models. Our results showed that tracked geese used the eastern Patagonian route to reach their breeding grounds and take the same route after breeding. Spring migration was significantly faster than autumn migration, at least based on the number of days spent in their stop-overs. Stop-overs were closer to the final destination, either during spring and autumn migrations, though some of them were not used during subsequent migrations. Our migration cartography for Ruddy-headed Geese, together with the timing and location data, should be used to improve conservation efforts directed at this species and might contribute to the modification of the current status of ‘Least Concern’ under the IUCN criteria.
