Browsing by Subject "voyageurs national park"

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    2021-2022 Greater Voyageurs Ecosystem wolf pack and population size report
    (2022) Gable, Thomas D; Homkes, Austin T; Bump, Joseph K
    This 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.
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    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%.