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Durbach, I., Borchers, D., Sutherland, C., Sharma, K. (2020). Fast, flexible alternatives to regular grid designs for spatial
capture–recapture..
Abstract: Spatial capture–recapture (SCR) methods use the location of
detectors (camera traps, hair snares and live-capture traps) and the locations at which animals were detected (their spatial capture histories) to estimate animal density. Despite the often large expense and effort involved in placing detectors in a landscape, there has been relatively little work on how detectors should be located. A natural criterion is to place traps so as to maximize the precision of density estimators, but the lack of a closed-form expression for precision has made optimizing this criterion computationally demanding. 2. Recent results by Efford and Boulanger (2019) show that precision can be well approximated by a function of the expected number of detected individuals and expected number of recapture events, both of which can be evaluated at low computational cost. We use these results to develop a method for obtaining survey designs that optimize this approximate precision for SCR studies using count or binary proximity detectors, or multi-catch traps. 3. We show how the basic design protocol can be extended to incorporate spatially varying distributions of activity centres and animal detectability. We illustrate our approach by simulating from a camera trap study of snow leopards in Mongolia and comparing estimates from our designs to those generated by regular or optimized grid designs. Optimizing detector placement increased the number of detected individuals and recaptures, but this did not always lead to more precise density estimators due to less precise estimation of the effective sampling area. In most cases, the precision of density estimators was comparable to that obtained with grid designs, with improvement in some scenarios where approximate CV(¬D) < 20% and density varied spatially. 4. Designs generated using our approach are transparent and statistically grounded. They can be produced for survey regions of any shape, adapt to known information about animal density and detectability, and are potentially easier and less costly to implement. We recommend their use as good, flexible candidate designs for SCR surveys when reasonable knowledge of model parameters exists. We provide software for researchers to construct their own designs, in the form of updates to design functions in the r package oSCR. |
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Korablev, M. P., Poyarkov, A. D., Karnaukhov, A. S., Zvychaynaya, E. Y., Kuksin, A. N., Malykh, S. V., Istomov, S. V., Spitsyn, S. V., Aleksandrov, D. Y., Hernandez-Blanco, J. A., Munkhtsog, B., Munkhtogtokh, O., Putintsev, N. I., Vereshchagin, A. S., Becmurody, A., Afzunov, S., Rozhnov, V. V. (2021). Large-scale and fine-grain population structure and genetic diversity of snow leopards (Panthera uncia Schreber, 1776) from the northern and western parts of the range with an emphasis on the Russian population. Conservation Genetics, .
Abstract: The snow leopard (Panthera uncia Schreber, 1776) population in Russia and Mongolia is situated at the northern edge of the range, where instability of ecological conditions and of prey availability may serve as prerequisites for demographic instability and, consequently, for reducing the genetic diversity. Moreover, this northern area of the species distribution is connected with the western and central parts by only a few small fragments of potential habitats in the Tian-Shan spurs in China and Kazakhstan. Given this structure of the range, the restriction of gene flow between the northern and other regions of snow leopard distribution can be expected. Under these conditions, data on population genetics would be extremely important for assessment of genetic diversity, population structure and gene flow both at regional and large-scale level. To investigate large-scale and fine-grain population structure and levels of genetic diversity we analyzed 108 snow leopards identified from noninvasively collected scat samples from Russia and Mongolia (the northern part of the range) as well as from Kyrgyzstan and Tajikistan (the western part of the range) using panel of eight polymorphic microsatellites. We found low to moderate levels of genetic diversity in the studied populations. Among local habitats, the highest heterozygosity and allelic richness were recorded in Kyrgyzstan (He = 0.66 ± 0.03, Ho = 0.70 ± 0.04, Ar = 3.17) whereas the lowest diversity was found in a periphery subpopulation in Buryatia Republic of Russia (He = 0.41 ± 0.12, Ho = 0.29 ± 0.05, Ar = 2.33). In general, snow leopards from the western range exhibit greater genetic diversity (He = 0.68 ± 0.04, Ho = 0.66 ± 0.03, Ar = 4.95) compared to those from the northern range (He = 0.60 ± 0.06, Ho = 0.49 ± 0.02, Ar = 4.45). In addition, we have identified signs of fragmentation in the northern habitat, which have led to significant genetic divergence between subpopulations in Russia. Multiple analyses of genetic structure support considerable genetic differentiation between the northern and western range parts, which may testify to subspecies subdivision of snow leopards from these regions. The observed patterns of genetic structure are evidence for delineation of several management units within the studied populations, requiring individual approaches for conservation initiatives, particularly related to translocation events. The causes for the revealed patterns of genetic structure and levels of genetic diversity are discussed.
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Moheb, Z., Rajabi, A. M., Jahed, N., Ostrowski, S., Zahler, P. I., Fuller, T. K. (2022). Using double-observer surveys to monitor urial and ibex populations in the Hindu Kush of Wakhan National Park, Afghanistan. Oryx, , 1–7.
Abstract: We surveyed the urial Ovis vignei and Siberian ibex Capra sibirica in the Hindu Kush mountain range of Wakhan National Park in north-eastern Afghanistan to determine their population status and identify potential drivers of population change. We conducted two double- observer ground surveys, in April–May 2015 and 2018, in 10 areas (total = 288 km2). Urial herds were mostly com- posed of both sexes (78% of observed herds), the mean adult sex ratio (females:males) was 100:70, and the mean female:juvenile ratio was 100:53. In 2018 we calculated a urial density of 35/100 km2, compared to 72/100 km2 in 2015. Ibex herds were mostly (79%) composed of both sexes, the mean adult sex ratio (females:males) was 100:103, and the mean female:juvenile ratio was 100:58. Ibex density estimates were similar in 2015 and 2018 (c. 250/100 km2). We discuss the usefulness of the double-observer methods for ungulate surveys, highlight the value of viewshed calculations and discuss the possible causes of urial population decline. To ensure the conservation of these ungulate populations, we recommend continued regular monitoring, measures to address poaching and research to clarify the taxonomical status of urials in Wakhan.
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Ghoshal, A., Bhatnagar, Y. V., Pandav, B., Sharma, K., Mshra, C. (2017). Assessing changes in distribution of the Endangered snow leopard Panthera uncia and its wild prey over 2 decades in the Indian Himalaya through interviewbased occupancy surveys. Oryx, , 1–13.
Abstract: Understanding species distributions, patterns of
change and threats can form the basis for assessing the conservation status of elusive species that are difficult to survey. The snow leopard Panthera uncia is the top predator of the Central and South Asian mountains. Knowledge of the distribution and status of this elusive felid and its wild prey is limited. Using recall-based key-informant interviews we estimated site use by snow leopards and their primary wild prey, blue sheep Pseudois nayaur and Asiatic ibex Capra sibirica, across two time periods (past: �; recent: �) in the state of Himachal Pradesh, India. We also conducted a threat assessment for the recent period. Probability of site use was similar across the two time periods for snow leopards, blue sheep and ibex, whereas for wild prey (blue sheep and ibex combined) overall there was an % contraction. Although our surveys were conducted in areas within the presumed distribution range of the snow leopard, we found snow leopards were using only % of the area (, km). Blue sheep and ibex had distinct distribution ranges. Snow leopards and their wild prey were not restricted to protected areas, which encompassed only % of their distribution within the study area. Migratory livestock grazing was pervasive across ibex distribution range and was the most widespread and serious conservation threat. Depredation by free-ranging dogs, and illegal hunting and wildlife trade were the other severe threats. Our results underscore the importance of community-based, landscape- scale conservation approaches and caution against reliance on geophysical and opinion-based distribution maps that have been used to estimate national and global snow leopard ranges. |
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Tumursukh, L., Suryawanshi, K. R., Mishra, C., McCarthy, T. M., Boldgiv, B. (2015). Status of the mountain ungulate prey of the Endangered snow leopard Panthera uncia in the Tost Local Protected Area, South Gobi, Mongolia. Oryx, , 1–6.
Abstract: The availability of wild prey is a critical predictor of carnivore density. However, few conservation pro- grammes have focused on the estimation and monitoring of wild ungulate populations and their trends, especially in the remote mountains of Central Asia. We conducted double-observer surveys to estimate the populations of ibex Capra sibirica and argali Ovis ammon in the mountain- ous regions of Tost Local Protected Area, South Gobi prov- ince, Mongolia, which is being considered for designation as a Nature Reserve. We also conducted demographic surveys of the more abundant ibex to examine their sex-ratio and the survival of young during –. The estimated ibex population remained stable in  and  and the es- timated argali population increased from  in  to  in . The biomass of wild ungulates was c. % that of live- stock. Mortality in young ibex appeared to increase after weaning, at the age of  months. We estimated the popula- tion of wild ungulates was sufficient to support – adult snow leopards Panthera uncia. The adult snow leopard population in our study area during –, estimated independently using camera-trap-based mark–recapture methods, was –. Based on our results we identify the Tost Local Protected Area as an important habitat for the conservation of these ungulates and their predator, the Endangered snow leopard, and recommend elevation of its status to a Nature Reserve.
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Ale, S., Shrestha, B., and Jackson, R. (2014). On the status of Snow Leopard Panthera Uncia (Schreber 1775) in Annapurna, Nepal. Journal of Threatened Taxa, (6(3)), 5534–5543.
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Thapa, K., Pradhan, N, M, B., Barker, J., Dhakal, M., Bhandari, A, R., Gurung, G, S., Rai, D, P., Thapa, G, J., Shrestha, S., Singh, G, R. (2013). High elevation record of a leopard cat in the Kangchenjunga Conservation Area, Nepal. Cat News, (No 58), 26–27.
Abstract: During a camera trapping survey in Khambachen valley of Kangchenjunga Conservation
Area KCA from 24 April to 26 May 2012 we camera trapped one leopard cat Prionailurus bengalensis at an altitude of 4,474 meter. This is probably the highest altitudinal record for the species in its range. Additionally, one melanistic leopard Panthera pardus was captured at an altitude of 4,300 m, which is probably as well the highest documented record in the country. Yet at this stage, no obvious reason can explain these unusual high records for both species, thus more surveys are recommended for this region. |
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Maheshwari, A., Sharma, D. (2010). Snow leopard conservation in Uttarakhand and Himachal Pradesh.
Abstract: The Greater and Trans Himalayan regions of Uttarakhand and Himachal Pradesh have great potential in terms of wildlife (flora and fauna). This survey was the first ever survey for the snow leopard in Uttarakhand and some of the areas of Himachal Pradesh till date. It confirms the presence of snow leopard in Uttarakhand on the basis of indirect evidence. We could not find any evidence of snow leopard from surveyed areas in Himachal Pradesh – but it certainly does not mean that there are no snow leopards in the surveyed areas.
Areas above 3000m elevation were selected for this survey in 10 protected areas of both the states. Status and distribution of snow leopard was assessed through indirect evidence (n=13) found between 3190 and 4115m. On average, one indirect evidence of snow leopard was found for every 39km walked. About 39% of the evidence was found on the hill-slope followed by valley floor (30%), cliff (15%) and 8% from both stream bed and scree slope. Preferred mean slope was 28° (maximum 60°). Snow leopard-human conflicts were assessed through questionnaire surveys from Govind Pashu Vihar, Askot Wild Life Sanctuary and Dung (Munsiari) areas. They revealed that livestock depredation is the only component of conflict and contributed to 36% of the total diet (mule, goat and sheep) of snow leopard. Blue sheep and rodents together comprised 36.4% of the total diet. |
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Jackson, R., Hunter, D.O. (1995). Snow leopard Survey and conservation handbook (First edition).
Abstract: The objectives of this handbook (First edition) are to provide standard procedures for conducting snow leopard status and distribution surveys; suggest uniform methods for assessing the status and relative abundance of large prey species (ungulates such as blue sheep, argali, markhor, Himalayan tahr, urial, ibex, red deer, and roe deer); offer guidance in evaluating habitat quality and identifying the major environmental factors affecting species welfare; and provide standard forms for reporting the results of these field surveys, and a process for feeding information developed by the International Snow Leopard Trust into Snoe Leopard Information Management System (SLIMS).
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Sarkar, P., Takpa, J., Ahmed, R., Tiwari, S. K., Pendharkar, A., ul-Haq, S., Miandad, J., Upadhyay, A., Kaul, R. (2008). Mountain Migrants. Survey of Tibetan Antelope (Pantholops hodgsonii) and Wild Yak (Bos grunniens) in Ladakh, Jammu & Kashmir, India. India.
Abstract: The Tibetan antelope (Pantholops hodgsonii), locally called chiru, is mainly confined to the Tibetan plateau in China. A small population migrates into Chang Thang in eastern Ladakh in the state of Jammu and Kashmir in India. The chiru has a geographical range extending approximately 1,600 km across the Tibetan Plateau, with an eastern limit near Ngoring Hu (Tibet Autonomous Region) and a western limit in Ladakh (India). Large-scale hunting for wool and meat has resulted in a decline of its population and only an estimated 75,000 individuals of this species survive in the world today. Its status in India has not been studied in any detail, although sporadic spot surveys have been done in the past. Similarly, very little information is available on status of wild yak (Bos grunniens), the progenitor (closest ancestor) of the domestic yak in India. The animal is distributed mainly in the highlands of the Tibetan plateau including the Qinghai province, Tibetan and Xinjiang autonomous regions and the Quilian mountains in the Gansu province. Small nomadic isolated populations are reported from Ladakh in Jammu and Kashmir (J&K), and even smaller numbers occasionally from Himachal Pradesh, Uttarakhand, Sikkim and Arunachal Pradesh in India. To obtain further information primarily about these two species, the Department of Wildlife Protection, Jammu & Kashmir (DWP) along with the Wildlife Trust of India (WTI) and the Indian Army initiated surveys in Ladakh in the years 2005 and 2006. Surveys were conducted in the Chang Thang and Karakoram Wildlife Sanctuaries of Ladakh in Jammu & Kashmir. The Chang Chenmo (Chang Thang) area lies in the eastern part of Ladakh just north of the famous Pangong Lake, while the Karakoram WLS lies in the north-eastern part of Ladakh, south of the Karakoram Pass. The team found 250 – 300 chiru in the Karakoram area in addition to other mammal species. Both male and female chiru were sighted here between altitudes of 4735 m and 5336 m. A total of 230 individuals were sighted (after deleting double counts) in the year 2005 and 45 individuals in 2006. Based on this, it is estimated that between 250-300 individuals occur in this area. Mean group size of chiru was 4.66±0.435 and varied between one to 34 individuals during 2005, and 4.5 ± 2.77 (SE) during 2006. Apart from chiru, other species encountered from the area includes Tibetan wolf (Canis lupus chanco), red fox (Vulpes vulpes), pale or mountain weasel (Mustela altaica), snow leopard (Uncia uncia), Ladakh urial (Ovis vignei), blue sheep (Pseudois nayaur), woolly hare (Lepus oiostolus), Ladakh pika (Ochotona ladacensis), Royle's pika (Ochotona roylei), Nubra pika (Ochotona nubrica), plateau pika (Ochotona curzoniae), Stoliczka's mountain vole (Alticola stoliczkanus) and silvery mountain vole (Alticola argentatus).
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