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Bischof, R., Hameed, S., Ali, H., Kabir, M., Younas, M., Shah, K. A., Din, J. U., Nawaz, M. A. (2013). Using time-to-event analysis to complement hierarchical methods when assessing determinants of photographic detectability during camera trapping. Methods in Ecology and Evolution, .
Abstract: 1. Camera trapping, paired with analytical methods for estimating occupancy, abundance and other ecological parameters, can yield information with direct consequences for wildlife management and conservation. Although ecological information is the primary target of most camera trap studies, detectability influences every aspect from design to interpretation.
2. Concepts and methods of time-toevent analysis are directly applicable to camera trapping, yet this statistical field has thus far been ignored as a way to analyze photographic capture data. to illustrate the use to time-to-event statistics and to better understand how photographic evidence accumulates, we explored patterns in tow related measure of detectability: Detection probability and time to detection. We analyzed camera trap data for three sympatric carnivores ( snow Leopard, red fox and stone marten) in the mountains of northern Pakistan and tested predictions about patterns in detectability across species, sites and time.
3. We found species-specific differences in the magnitude of detectability and the factors influencing it, reinforcing the need to consider determinants of detectability in study design and to account for them during analysis. Photographic detectability of snow leopard was noticeably lower than that of red fox, but comparable to detectability of stone marten. Site-specific attributes such as the presence of carnivore sign ( snow Leopard), terrain ( snow leopard and red fox) and application for lures ( red fox) influenced detectability. For the most part, detection probability was constant over time.
4. Species- specific differences in factors determining detectability make camera trap studies targeting multiple species particularly vulnerable to misinterpretation if the hierarchical origin of the data is ignored. Investigators should consider not only the magnitude of detectability, but also the shape of the curve describing the cumulative process of photographic detection, as this has consequences for both determining survey effort and the election of analytical models. Weighted time-to -event analysis can complement occupancy analysis and other hierarchal methods by providing additional tools for exploring camera trap data and testing hypotheses regarding the temporal aspect of photographic evidence accumulation.
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Fox, J. L., & Chundawat, R. S. (1988). Observations of snow leopard stalking, killing and feeding behavior. Mammalia, 52(1), 137–140.
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Marma, B. B., & Yunchis, V. V. (1968). Observations on the breeding, management and physiology of Snow leopards (Panthera u. uncia) at Kaunas Zoo from 1962 to 1967. In C. Jarvis, & R. Biegler (Eds.), Canids and Felids in Captivity (pp. 66–73). Zoological Society of London.
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Meiers, S. T. (1992). Habitat use by captive puma (Felis concolor) and snow leopards (Pathera uncia) at the Lincoln Park Zoo, Chicago, Illinois. Ph.D. thesis, DePaul University, .
Abstract: Between May 1990 and January 1991, behavioral observations were made of two captive pumas (Felis concolor Linnaeus), and two captive snow leopards (Panthera uncia Schreber) in their outdoor exhibits at the Lincoln Park Zoological Gardens, Chicago, Illinois. Behaviors compared within and between species included: 1) time spend in the different habitat types; 2) time budgets for the different behaviors: laying, moving, sitting, standing, crouching, in the tree, drinking, urinating, defecating, within their inside dens, and “behavior not determined” when the identity or behavior of the individuals could not be determined; and 3) mobility of the animals within their exhibits. Also examined were: 4) preferences for different habitat types; 5) recommendations for future exhibit designs. Both species located themselves within their exhibits in a non-random manner. The majority of cats' time was spent in elevated locations (i.e., gunite ledges approximately 1-5.5 m above ground-level). Snow leopards exhibited this tendency to a greater extent than did the pumas. Both species also spent the majority of their time in the lying-down behavior; again snow leopards displayed this tendency significantly more than the pumas. Pumas were highly mobile and changed locations and behaviors in their exhibit significantly more than the snow leopards. No significant differences were noted between conspecifics in regard to habitat type preference, or mobility within the exhibit. Suggestions for future exhibit design include elevated locations for the cats to lay and look around within and outside their exhibits, caves for access to shade or relief from inclement weather, and ground surfaces to move about on. Features for exhibit design should take into consideration the natural habitat of the cat to occupy the exhibit.
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Nath, A. (1982). Some observations on wildlife in the Upper Suru/Northern Zanskar/Markha Valley of Ladakh. In L. Blomqvist (Ed.), International Pedigree Book of Snow Leopards, Vol. 3 (Vol. 3, pp. 11–24). Helsinki: Helsinki Zoo.
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Wahlberg, C., Tarkkanen, A., & Blomqvist, L. (1982). Further observations on the multiple ocular coloboma (MOC) in the snow leopard, Panthers uncia. In L. Blomqvist (Ed.), International Pedigree Book of Snow Leopards (Vol. 3, pp. 139–144). Helsinki: Helsinki Zoo.
Abstract: The first observation of the occurrence of multiple ocular coloboma (MOC) in a snow leopard was reported in the International Pedigree Book of Snow Leopards Volume I in 1978 (1). The lesions in this syndrome consist of coloboma of the upper eye lid and uveal coloboma of the globe. Even colobomatous retinal cysts and retinal dysplasia have been noted. The ethiology of in all ten cases of MOC in the snow leopards kept at the Helsinki Zoo were described and discussed in detail in Volume II of the International Pedigree Book of Snow Leopards (2,3). Three cases of MOC in the snow leopards kept at Henry Doorly Zoo, Omaha, Ne., have been described by Phillips (4), one case is known of in Amsterdam (van Bree, personal communication), and two cases in Zoo Zurich (Isenbugel and Weilenmann, pers. comm.) The ethiology of the defect is still not known although various theories ranging from genetic to exogenous factors have been presented.
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