Browsing by Subject "home range"
Item 2021-2022 Greater Voyageurs Ecosystem wolf pack and population size report(2022) Gable, Thomas D; Homkes, Austin T; Bump, Joseph KThis report presents and discusses data on wolf population metrics collected during 2021-2022 in the Greater Voyageur Ecosystem, Minnesota. In 2021-2022, we estimated the area of 9 wolf pack home ranges/territories, determined the size of 14 wolf packs, and obtained 7.3 independent observations of the same size for each pack. The survey effort in 2021-2022 was the same as 2020-2021 and represents the most intensive survey effort, in terms of number of packs and territories studied, to date in the Greater Voyageurs Ecosystem. We estimate that wolf population density in the Greater Voyageurs Ecosystem in 2021-2022 was 63.2 wolves/1000 km2 (95% confidence interval: 50.3-83.8 wolves/1000 km2). This density represents a 16% increase in population density from 2020-2021 and a 48% increase from the recent population low in 2019-2020 of 42.7 wolves/1000 km2. The increase in population density is largely attributable to increased pup survival, which likely increased pack size. We compared current wolf population density and population metrics to historical wolf density and population metrics in the Greater Voyageurs Ecosystem. This assessment suggests that wolf density in the GVE has changed little since the late 1980's, and that the GVE has sustained a high-density wolf population for decades.Item 2023-2024 Greater Voyageurs Ecosystem Wolf Population Report(2024-10-11) Gable, Thomas D.; Homkes, Austin T.; Bump, Joseph K.During April 2023-April 2024, we studied the wolf population in the Greater Voyageurs Ecosystem (GVE), Minnesota to understand wolf population dynamics and how changes in population dynamics are connected to or influence predation behavior, wolf pup survival, and changes in prey density. We estimate that wolf population density in the Greater Voyageurs Ecosystem in 2023-2024 was 55.4 wolves/1000 km^2, a 15% decrease in wolf population density from 2022-2023 (65.1 wolves/1000 km^2). Because average pack size remained virtually the same between 2022-2023 and 2023-2024 (4.2 wolves vs 4.3 wolves), the decrease in population density can be attributed entirely to a substantial increase in territory size. Indeed, average territory size increased by 21% from 95.5 km^2 in 2022-2023 to 115.6 km^2 in 2023-2024. With the increase in territory size came a marginal increase (3.6 km^2) in territory overlap between neighboring packs that reduced, to a small degree, the effects of increased territory size on overall population density; i.e., territory size increased by 21% but population density only decreased by 15%.Item Fishing Cat Ecology: Food Habits, Home Ranges, Habitat Use and Mortality in a Human-Dominated Landscape around Khao Sam Roi Yot, Peninsular Thailand(2015-06) Cutter, PassananAbstract Despite their global status as an endangered species, many aspects of fishing cat (Prionailurus viverrinus) ecology have not been studied in detail in the wild. The objectives of this study were to understand food habits, habitat use, home range patterns, and causes of mortality in a predominantly agricultural landscape in the area in and around Khao Sam Roi Yot National Park, Prachuap Khiri Khan Province, peninsular Thailand. Few studies have been conducted on the food habits of wild fishing cats and none has been conducted in Southeast Asia. I identified prey remains in fishing cat scats to estimate composition and relative occurrence of major prey groups in the feces of 194 fishing cat scats collected over an approximately 35 km2 area. The proportion of prey remains found in scats was 42% fish, 24% mammals, 24%, birds, 5% reptiles, and 2% crustaceans. There was a significant difference in seasonal prey composition (p = 0.001). During the dry season, 47% of prey remains found was fish, 11 % mammal, 29% bird, 11% reptile, and 3% crustacean. In the wet season, proportions were 36% fish, 39% mammal, 20% bird, 2% reptile, and 1% crustacean. In this study, fishing cat diet varied more than previously reported, both in terms of the diversity of prey and in the proportions of major groups recorded between seasons. To study the home range, habitat use, and mortality of fishing cats, I captured seventeen cats (seven females and 10 males) using box traps and fitted 16 with VHF radio collars. Data from these animals (>1000 locations) were used to estimate home range size and habitat selection. Home range size was estimated using 100% Minimum Convex Polygon (MCP) and the 95% Fixed Kernel (FK) methods. Fishing cats essentially maintained their core area for the duration of the study despite seasonal changes in diet. For the 100% MCP, the area of the male annual home range, F5 was 13.5 km2 and M8 was 4 km2 and the mean for female annual home ranges (n=4) was 4.0 km2. Whereas, the 95% estimates for the male annual home range was 8.8 km2, and the mean annual home range for females was 3.9 km2. Seasonal home range was estimated for one male. His wet season 100% MCP was 10.8 km2, and his 95% fixed kernel was 12.6 km2. In the dry season his 100% MCP home range was 5.7 km2 and the 95% fixed kernel home range was 8.9 km2. For females (n=4), mean wet season 100% MCP home range was 3.2 km2 and the mean 95% fixed kernel was 3.1 km2. The dry season mean 100% MCP was 3.0 km2 and the mean 95% fixed kernel was 3.2 km2. There is evidence of overall home range overlap between females but their 50% area had no overlap. Fishing cats used aquaculture areas and rice fields more frequently, than mangrove restoration areas, and coconut plantations, and human settlement and limestone hills were avoided. One animal used primarily mangrove vegetation (97% of all locations). Coconut plantation was a relatively rare vegetation type within the study area, but it was the most used habitat for one animal in the dry season. Of 16 cats originally collared, five died from confirmed poaching or retribution killing (31.3%), dead from unknown causes (n=6, 37.5%), unknown fate (n=3, 18.8%), and collar malfunction (n=2, 12.5%). Considering that fishing cats have been known to live to 10 years of age, the sample in this study sustained a relatively high mortality rate. Because poaching and retaliatory killing was the main cause of death, the most effective conservation effort for this species in coastal Thailand should focus on decreasing human-fishing cat conflict and poaching.Item Home range overlap indices implemented using kernel density estimators with plug-in smoothing parameters and Program R(2014-04-18) Fieberg, John R; jfieberg@umn.edu; Fieberg, John RThis collection contains R code to implement the home range overlap indices evaluated by Fieberg and Kochanny (2005). These indices have been incorporated into the adehabitat package of Program R. However, the adehabitat package does not currently (as of April 2014) allow calculation of home ranges using the 'plug-in' method for choosing smoothing parameters when estimating home ranges using kernel density estimates. In addition, the code here allows one to use two separate smoothing parameters rather than a single parameter (as in the current version of adehabitat). An illustrative example is included that makes use wild boar location data contained in the adehabitat package. For references, see README.txt.