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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. |
Feh, C. (2001). Ecology and social structure of the Gobi khulan Equus hemionus subsp. in the Gobi B. National Park, Mongolia. Biological Conservation, 101, 51–61.
Abstract: The status of the Gobi khulan Equus hemionus subsp. is recorded as ``insufficiently known'' in the Species Survival Commission's Equid Action Plan. Recent counts confirm that Mongolia holds the most important population of the whole species. Since 1953, the animals have benefited from a protected status, but this is now challenged. A 5-year study in the B part of the Gobi National Park on one subpopulation showed that it has remained stable over the past 15 years with an adequate mean reproductive rate of 15% and a 50% survival rate over the first year. Age/sex related mortality and prey analysis indicate that wolf predation probably has some impact on the population, in particular for 4-6-year-olds of both sexes at the start of reproduction. Desert and mountain steppes are the khulan's year-round preferred habitat, but `oases', play an important role at the beginning of lactation. Anthropogenic factors affect both home range and habitat use through direct intervention or permanent occupation of the scarce water sources. Khulans of this subpopulation, unlike other Asian and African wild asses, form year-round stable, non-territorial families. These families and all-male groups join together into ``bands'' in winter, and herds of several hundred animals, where reproductive rate is highest, form throughout the year. The existence of such herds may thus be critical for the breeding success of the population. Our study provides the first detailed quantitative data for this subspecies, which will help to monitor changes in the future. # 2001 Elsevier Science Ltd. All rights reserved.
Keywords: Equus hemionus; Ecology and social structure; Gobi National Park; Mongolia; 5250
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McCarthy, T. (2000). Ecology and Conservation of Snow Leopards, Gobi Brown Bears, and Wild Bactrian Camels in Mongolia. Ph.D. thesis, University of Massachusetts, Amherst, .
Abstract: Snow leopard ecology, distribution and abundance in Mongolia were studied between 1993 and 1999. I placed VHF and satellite radio-collars on 4 snow leopards, 2 males and 2 females, to determine home ranges, habitat use, movements, and activity. Home ranges of snow leopards in Mongolia were substantially larger than reported elsewhere. Males ranged over 61 – 142 km2 and female 58 to 1,590 km2. Cats had crepuscular activity patterns with daily movements averaging 5.1 km. Intraspecific distances averaged 1.3 km for males to 7.8 km for males. Leopards selected moderately to very-broken habitat with slopes > 20o, in areas containing ibex. Leopard distribution and abundance was determined using sign surveys. Leopard range in Mongolia is approximately 103,000 km2 but cats are not uniformly distributed within that range. High-density areas include the eastern and central Transaltai Gobi and the northern Altai ranges. Relative leopard densities compared well with relative ibex densities on a regional basis. A snow leopard conservation plan was drafted for Mongolia that identifies problems and threats, and provides an action plan. Wild Bactrian camels occur in the Great Gobi National Park (GGNP) and are thought to be declining due to low recruitment. I surveyed camels by jeep and at oases, observing 142 (4.2% young) and 183 (5.3% young) in 1997 and 1998. Current range was estimated at 33,300 km2. Some winter and calving ranges were recently abandoned. Track sizes and tooth ages from skulls were used to assess demographics. A deterministic model was produced that predicts camel extinction within 25 to 50 years under current recruitment rates and population estimates. Gobi brown bears are endemic to Mongolia and may number less than 35. Three population isolates may occur. I collected genetic material from bears at oases using hair traps. Microsatellite analyses of nuclear DNA determined sixteen unique genotypes, only two of which occurred at more than one oases. Genetic diversity was very low with expected heterozygosity = 0.32, and alleles per locus = 2.3. Mitochondrial DNA sequences were compared to other clades of brown bear and found to fall outside of all known lineages.
Keywords: snow leopard; Uncia uncia; Mongolia; radio-collar; habitat use; movements; ecology; wild camel; brown bear; 5340
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Oli, M. K. (1991). Ecology and conservation of snow leopard project (Vol. 6628). |
Ming, M., Yun, G., & Bo, W. (2008). Chinese snow leopard team goes into action. Man & the Biosphere, 54(6), 18–25.
Abstract: China, the world's most populous country, also contains the largest number of Snow Leopards of any country in the world. But the survey and research of the snow leopard had been very little for the second half of the 20th century. Until recent years, the members of Xinjiang Snow Leopards Group (XSLG/SLT/XFC) , the Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences have been tracking down the solitary animal. The journal reporter does a face-to-face interview with professor Ma Ming who is a main responsible expert of the survey team. By the account of such conversation, we learn the achievements, advances and difficulty of research of snow leopards in the field, Tianshan and Kunlun, Xinjiang, the far west China, and we also know that why the team adopt the infrared camera to capture the animals. Last but not least professor talked about the survival menace faced by the Snow Leopards in Xinjiang.
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Novikov, G. A. (1962). Carnivorous mammals of the fauna of the USSR. Ussr: Zool. Inst. Acad. Sci.
Abstract: Brief review of physical characteristics, (skull illustration) ecology and distribution
Keywords: Ussr; Russia; ecology; distribution; skull-illustration; Soviet-Union; browse; soviet union; soviet; union; skull illustrations; skull; illustrations; 3140
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Fox, J. L., & Freeman, H. (1984). An Internationally cooperative fiels study of the snow leopard in Northern India. In L.Blomqvist (Ed.), (Vol. 4, pp. 39–42). Helsinki, Finland: Leif Blomqvist and Helsinki Zoo. |
Anonymous. (2000). A snow leopard conservation plan for Mongolia.
Abstract: The snow leopard faces multiple threats in the Himalayan region, from habitat degradation, loss of prey, the trade in pelts, parts and live animals, and conflict with humans, primarily pastoralists. Consequently, the populations are considered to be in decline and the species is listed as Endangered in the IUCN's Red List. As a 'flagship' and 'umbrella' species the snow leopard can be a unifying biological feature to raise awareness of its plight and the need for conservation, which will benefit other facets of Himalayan biodiversity as well. Some studies of snow leopards have been conducted in the Himalayan region. But, because of its elusive nature and preference for remote and inaccessible habitat, knowledge of the ecology and behaviour of this mystical montane predator is scant. The available information, however, suggests that snow leopards occur at low densities and large areas of habitat are required to conserve a viable population. Thus, many researchers and conservationists have advocated landscape-scale approaches to conservation within a regional context, rather than focusing on individual protected areas.This regional strategy for WWF's snow leopard conservation program is built on such an approach. The following were identified as important regional issues: 1) international trade in snow leopards and parts; 2) the human-snow leopard conflict; 3) the need for a landscape approach to conservation to provide large spatial areas that can support demographically and ecologically viable snow leopard metapopulations; 4) research on snow leopard ecology to develop long-term, science-based conservation management plans; and 5) regional coordination and dialog. While the issues are regional, the WWF's in the region have developed 5-year strategic actions and activities, using the regional strategies as a touchstone, which will be implemented at national levels. The WWF's will develop proposals based on these strategic actions, with estimated budgets, for use by the network for funding and fund-raising. WWF also recognizes the need to collaborate and coordinate within the network and with other organizations in the region to achieve conservation goals in an efficient manner, and will form a working group to coordinate activities and monitor progress.
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Fox, J. L. (1989). A review of the status and ecology of the snow leopard (Panthera uncia). |
Fox, J. (1989). A Review of the Status and Ecology of the Snow Leopard (Panthera uncia). International Snow Leopard Trust. |