Spelling suggestions: "subject:"habitat occupancy"" "subject:"abitat occupancy""
1 |
Assessing Mammal and Bird Biodiversity and Habitat Occupancy of Tiger Prey in the Hukaung Valley of Northern MyanmarNaing, Hla 17 July 2015 (has links) (PDF)
I used results from camera traps set for tigers (Panthera tigris) during 2001-2011 in the Hukaung Valley Wildlife Sanctuary of northern Myanmar to assess overall biodiversity of large mammal and bird species, and to identify differences in photo rates inside and outside of the most protected core area of the Sanctuary. A total of 403 camera stations were deployed during October-July in the dry seasons of 2001-2011, 260 inside the Core area and 143 Outside. From 10,750 trap-nights I obtained 2,077 independent photos of wildlife species and 699 of domestic animals and humans, including 35 species of wild mammals (19 carnivores, 4 primates, 1 elephant, 6 even-toed ungulates, 1 pangolin, and 4 rodents) and 16 species of wild birds. Of these, 1 is considered critically endangered, 7 are endangered, 11 are vulnerable, and 5 are nearly threatened. Some species that probably occur in the Sanctuary (e.g., arboreal or semi-aquatic mammals) were not photographed, likely because of camera placement. In total, 48 wild species were photographed in the Core area vs. only 33 at locations Outside of the core area. Generally, few photos of any domestic animal species were obtained inside 9 the Core area, and no photos insurgents were obtained there, but many more photos of poachers and villagers, but also park rangers, were obtained there. Increased patrol efforts may have helped maintain species presence in the Core area, but differences in photo rates between areas were likely mostly influenced by differences in elevation, slope, density of streams, trails, and roads, and perhaps vegetative cover type.
Tiger abundance is most influenced naturally by prey availability and anthropogenically by poaching. In the Hukaung Valley Wildlife Sanctuary in northern Myanmar, a major conservation area established to protect tigers, tiger presence has declined. This study was conducted to assess habitat occupancy and distribution of principal tiger prey species in the Core part of the Sanctuary by surveying for sign on 1650.9 km partitioned into 554 sampling units during November 2007 and May 2008. Using standard occupancy model in the program PRESENCE (6.2), habitat occupancy and detection probabilities were predicted and the best candidate model for each species was selected using the Akaike information criterion (AIC). By incorporating 7 environmental and 4 social covariates, the predicted habitat occupancy rates were 0.76 (SE=0.196, naïve estimate = 0.5162) for gaur (Bos gaurus), 0.91 (SE=0.03, naïve estimate = 0.7762) for sambar (Rusa unicolor), 0.57 (SE = 0.003, naïve estimate = 0.3195) for wild pigs (Sus scrofa) and 0.89 (SE = 0.001, naïve estimate = 0.7996) for muntjac (Muntiacus muntjak). Overall, shorter Euclidean distances to ranger stations and trails, decreased stream density, and broadleaved evergreen/semi-deciduous forest and relatively rare rain-fed cropland habitat occurrence positively influenced prey habitat occupancy; conversely, shorter Euclidean distances to villages, roads, and streams, higher elevations, and occurrence of mixed broadleaved and needle-leaved forest habitat 10 negatively influenced occupancy. In addition, Euclidean distance to ranger stations, trails, and roads positively affections species detections, whereas shorter Euclidean distance to villages and streams, high elevations, and high precipitation negatively affected detections. Results indicate that all four prey species were relatively well-distributed through the Sanctuary Core area. However, comparisons with tiger and prey indices of abundance elsewhere suggest that prey density is low and would not likely support many tigers.
|
2 |
Evaluating the conservation potential of urban and rural ecosystems for aquatic-breeding amphibians: a case study of two native frogs in southwestern British ColumbiaGreen, Jemma 27 September 2018 (has links)
The conservation of aquatic-breeding amphibian populations and their habitats is increasingly challenged by urban and rural development, which is occurring more intensively and more rapidly than ever before. Some species are now impacted by development throughout their range. This has forced a re-evaluation of the potential of developed landscapes for providing habitat and contributing to regional conservation strategies. For many amphibians, little is known about the criteria necessary for persistence in a developed landscape. Considerable variation in the physiology, habitat requirements, and movement behaviour of amphibians suggests that responses to habitat loss, alteration, and fragmentation are species-specific. In this thesis, I investigate species-habitat relationships for the northern red-legged frog (Rana aurora) and the Pacific chorus frog (Pseudacris regilla) in a mixed urban-rural landscape in southwestern British Columbia to evaluate the potential for species persistence despite urban and rural development throughout their range. I used repeat auditory surveys of the species’ breeding chorus to determine presence or absence at potential breeding wetlands. I then related species occurrence and abundance to characteristics of the aquatic and terrestrial environment measured at multiple spatial scales. Both species were found to use rural and urban wetlands, though R. aurora were rarely detected while P. regilla were common. Occurrence was best explained by characteristics of the terrestrial environment, rather than within-wetland characteristics, though influential terrestrial characteristics and their scale of impact differed between species. Within the context of the developed landscape, I identify species-specific positive and negative habitat associations and suggest the spatial scales at which management of these habitat characteristics will be most effective. These criteria may help to explain the species’ current distribution, prioritize management strategies, predict the effectiveness of habitat conservation and restoration projects, and inform development in municipalities seeking to maintain or enhance amphibian diversity. / Graduate / 2019-09-11
|
Page generated in 0.0646 seconds