Browsing by Author "Johnson-Bice, Sean M"

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    Data for: Wolves alter the trajectory of forests by shaping the central-place foraging behavior of an ecosystem engineer
    (2023-04-12) Gable, Thomas D; Johnson-Bice, Sean M; Homkes, Austin T; Fieberg, John R; Bump, Joseph K; gable079@umn.edu; Gable, Thomas D; University of Minnesota Voyageurs Wolf Project
    Dataset for Gable et al. 2023 where the authors describe how wolves indirectly alter the trajectory of forests by constraining the distance that beavers, a central place forager and prolific ecosystem engineer, forage from water. Specifically, Gable et al. demonstrate wolves wait-in-ambush and kill beavers on longer feeding trails than would be expected based on the spatiotemporal availability of beavers. This pattern is driven by temporal dynamics of beaver foraging: beavers make more foraging trips and spend more time on land per trip on longer feeding trails that extend farther from water. As a result, beavers are more vulnerable on longer feeding trails than shorter ones. Wolf predation appears to be a selective evolutionary pressure propelled by consumptive and non-consumptive mechanisms that constrain the distance from water beavers forage, which in turn limits the area of forest around wetlands, lakes, and rivers beavers alter through foraging. Thus, wolves appear intricately linked to boreal forest dynamics by shaping beaver foraging behavior, a form of natural disturbance that alters the successional and ecological states of forests.
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    R Code and Data Supporting: Ecological forecasts reveal limitations of common model selection methods: predicting changes in beaver colony densities
    (2020-04-20) Johnson-Bice, Sean M; Ferguson, Jake M; Erb, John D; Gable, Thomas D; Windels, Steve K; s.johnsonbice@gmail.com; Johnson-Bice, Sean M
    This repository contains the R and JAGS code supporting results reported in: Johnson-Bice, S.M., J.M. Ferguson, J.D. Erb, T.D. Gable, S.K. Windels (2020). Ecological forecasts reveal limitations of common model selection methods: predicting changes in beaver colony densities. Ecological Applications [In Press].
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    Single visits to active wolf dens do not impact wolf pup recruitment or pack size
    (2023-12-14) Gable, Thomas D; Johnson-Bice, Sean M; Homkes, Austin T; Bump, Joseph K; gable079@umn.edu; Gable, Thomas D; Voyageurs Wolf Project
    Dataset for Gable et al. where the authors used a quasi-experimental approach (reference vs. treatment) to determine whether visiting wolf dens and marking wolf (Canis lupus) pups affects important wolf population metrics. Specifically, Gable et al. examined whether pup recruitment and pack size differed between packs where they visited dens and handled pups (‘disturbed packs’ = treatment group) and those where they did not visit dens (‘undisturbed packs’ = reference group). During 2019-2023, they studied 43 wolf packs and litters, 19 of which were disturbed packs and 24 of which were undisturbed. They found no difference in recruitment or pack size between disturbed and undisturbed wolf packs. However, they did observe substantial annual variation in recruitment and pack size, which indicated that other ecological factors (e.g., prey abundance) were likely responsible for annual changes in recruitment and pack size. Their findings are consistent with several other studies, and together this research indicates that wolf dens can be visited once and wolf pups handled briefly for research purposes without having a measurable effect on recruitment and pack size.