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Ring-Tailed Lemur
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The golden langur, Trachypithecus geei, is among the world's 25 most endangered primates. It is endemic to India and Bhutan. Its distribution is limited to a small forest belt in western Assam in India and in Bhutan, between the River Manas in the east, River Sankosh in the west, and the Brahmaputra in the south. We carried out a survey of the golden langur in the Chakrashila Wildlife Sanctuary, the sole protected habitat for golden langurs in India, from December 2016 to March 2017. Modified line transects and total count methods were used for data collection. A total of 558 individuals in 72 groups were counted along the transects through direct sightings. Group size ranged from 2 to 18 individuals, with a mean size of 7.75. The adult male to female sex ratio was 1:2.06 and the ratio of adult females to infants was 1:0.461. The age structure of the population observed comprised 62.4% adults, 22.4% juveniles, and 15.2% infants. Encroachment, illegal tree felling, fuelwood collection and grazing by the different fringe villages are identified as major threats for golden langurs in and around the sanctuary. This information on the status and threats spectrum of the golden langur in Chakrashila Wildlife Sanctuary will help in formulating the future conservation and management guidelines.
The Sulawesi black macaque (Macaca nigra) population at Tangkoko Nature Reserve in North Sulawesi, Indonesia has been the focus of periodic study for over 30 years. The population has shown considerable decline during much of that time. Here we present the results of a long-term population survey of the Tangkoko M. nigra, conducted over the past decade, to provide updated information and on-going assessment of the population. Line-transect sampling was conducted annually from 1999 to 2002 and 2005 to 2011 along the same transect during a 2- to 3-week survey period. Although further decline in the population was observed at the outset of the survey, over the subsequent 12-year period we have seen stability in the population parameters with evidence of modest increases in both group and population density. During the 1999-2002 survey periods, there was a mean group density of 3.6 groups/km(2) and a mean population density of 39.8 individuals/km(2) . During 2005-2011, mean group density increased to 3.8 groups/km(2) and mean population density was 51.4 individuals/km(2) . The 2011 survey data indicated an estimated group density of 4.3 groups/km(2) and a population density of 61.5 individuals/km(2) . Given that our transect was located in the core of the Tangkoko reserve, our density estimates should be limited to that area of the reserve. One explanation for the apparent stabilization of the population may be tied to the increasing and sustained number of training and research programs being conducted at the reserve. This collective effort by local and international groups may be helping to reduce illegal activity in the reserve (i.e., hunting and habitat destruction) and generate greater awareness of this critically endangered species. Without the continued vigilance afforded by the existing research and training programs and the support and involvement of the local people, the M. nigra at the Tangkoko Nature Reserve will likely face further decline.
Red List assessment of the Grauer's subspecies of eastern gorilla. Uplisted from Endangered to Critically Endangered in 2016
Genetic analyses based on noninvasively collected samples have become an important tool for evolutionary biology and conservation. Crested macaques (Macaca nigra), endemic to Sulawesi, Indonesia, are important for our understanding of primate evolution as Sulawesi macaques represent an exceptional example of primate adaptive radiation. Crested macaques are also Critically Endangered. However, to date we know very little about their genetics. The aim of our study was to find and validate microsatellite markers useful for evolutionary, conservation, and other genetic studies on wild crested macaques. Using fecal samples of 176 wild macaques living in the Tangkoko Reserve, Sulawesi, we identified 12 polymorphic microsatellite loci through cross-species polymerase chain reaction amplification with later modification of some of these primers. We tested their suitability by investigating and exploring patterns of paternity, observed heterozygosity, and evidence for inbreeding. We assigned paternity to 63 of 65 infants with high confidence. Among cases with solved paternity, we found no evidence of extragroup paternity and natal breeding. We found a relatively steep male reproductive skew B index of 0.330 ± 0.267; mean ± SD) and mean alpha paternity of 65% per year with large variation across groups and years (29–100%). Finally, we detected an excess in observed heterozygosity and no evidence of inbreeding across our three study groups, with an observed heterozygosity of 0.766 ± 0.059 and expected heterozygosity of 0.708 ± 0.059, and an inbreeding coefficient of −0.082 ± 0.035. Our results indicate that the selected markers are useful for genetic studies on wild crested macaques, and possibly also on other Sulawesi and closely related macaques. They further suggest that the Tangkoko population of crested macaques is still genetically variable despite its small size, isolation, and the species’ reproductive patterns. This gives us hope that other endangered primate species living in small, isolated populations may also retain a healthy gene pool, at least in the short term.
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The online version of this article (doi:10.1007/s10764-017-9973-x) contains supplementary material, which is available to authorized users.
A population census of the Brown head spider monkey (Ateles fusciceps fusciceps) was performed in six localities in Northwestern Ecuador, nearby two large protected areas: Cotacahi Cayapas Ecological Reserve and Awá Ethnic Forest Reserve, using linear transects and playback techniques. A. f. fusciceps was found in four of the six localities, wherein the following demographic patterns were estimated: population density of 0.9 – 8.5 individuals/km2, abundance of 0.5 – 1.9 troops/10 km and an effective population size of 103.8 individuals in an area of approximate 17.6 km2. A. f. fusciceps showed a strong preference for forests in good conservation state, characterized by a continuous canopy cover and high numbers of large and tall trees. Daily activity patterns were found in all the study areas. The particular case of a solitary individual A.f. fusciceps living within a troop of Alouatta palliata was also studied, in a locality in Northwest Pichincha. The distribution of A. fusciceps was modeled using Maxent niche modeling prediction algorithm. Further, degraded areas were considered, in order to obtain a more realistic and updated distribution model. Currently, the distribution of A. f. fusciceps is concentrated in the interior part of Esmeraldas province, and adjacent regions of Imbabura and Carchi, as well as a small portion of Northwest Pichincha. A conservation status assessment for the species resulted in raking it as CR. Priorities areas for its conservation are the Cotacachi-Cayapas Ecological Reserve, Corredor Awacachi, Awa Ethnic Forest Reserve and the buffer and surrounding areas of this reserves (like Tesoro Esmeraldeño, Playa de Oro and Canande), and some forested areas in northwestern Pichincha. Finally, habitat loss and degradation, along with subsistence and commercial hunting were identified as the major threats for the species.
The ring-tailed lemur (Lemur catta) was once widely distributed throughout the south-central, far south, and southwest regions of Madagascar. This species is known for its marked ecological plasticity and ability to survive in a variety of habitats. Over the past decade, however, habitat destruction, forest fragmentation, hunting for subsistence or the illegal bushmeat trade, and live capture for the illegal pet trade have increased, resulting in extirpation or drastic reduction of populations throughout its geographic range. Recent mining activities in one region have resulted in further serious threats to remaining populations. In this paper, we discuss (1) population numbers and information on population extirpations, gathered over approximately the past six years, to illustrate the alarming decline of this well-known lemur, and (2) how the formerly accepted geographic range of L. catta now requires considerable revision. Population information was collected via on-the-ground surveys and censuses, or from reports by researchers at 34 sites where L. catta is or was recently present. Only three sites are known to contain populations of more than 200 animals. At 12 sites, populations number 30 or fewer individuals, and at 15 sites, L. catta has been recently extirpated, or populations are highly precarious and may become extinct in the very near future. Populations at three previously designated range limits have been extirpated. Many populations are surviving in small, isolated forest fragments, allowing for no male dispersal. With an estimate of just 2, 000-2, 400 individuals remaining in Madagascar, this iconic lemur may well become extinct in the wild in the near future, or at the very least, exist at only two or three widely dispersed sites.