Using thresholds to determine priorities for apex predator conservation in an urban landscape

How resource abundance and stochasticity affect organisms’ range sizes

“…Some species may respond to fluctuations in resource abundance by, if possible, switching to other food sources (Le Bot et al 2019; Steinmetz et al 2021), reducing energetic costs by lowering body heat (Schmidt et al 2020), or entering hibernation or torpor (Boyles et al 2020; Mohr et al 2020; Fjelldal et al 2021). However, movement represents one of the most readily available behaviors that species can adjust, whether this be by modifying their home range (Lucherini and Lovari 1996; Relyea et al 2000; Arechavala-Lopez et al 2019; Hirt et al 2021; Bista et al 2022; Bradsworth et al 2022; Yu et al 2022), migrating (Middleton et al 2018; Geremia et al 2019), moving nomadically (Nandintsetseg et al 2019; Teitelbaum and Mueller 2019), or dispersing (framework: Southwood 1977; amphibians: Cayuela et al 2020; Wheat et al 2017; birds: Pretorius et al 2020; mammals: Singh et al 2012).…”

“…Motile organisms can move to new locations in search of resources, but they must also account for a higher metabolism and movement costs (Taylor et al 1982). The hypothesis that space-use requirements decrease with resource abundance, E( R ), is commonly accepted and well supported, but many studies assume a linear relationship (e.g., Harestad and Bunnel 1979; Relyea et al 2000; McClintic et al 2014; Rizzuto et al 2021; Bista et al 2022; Bradsworth et al 2022). This is problematic because a linear relationship can lead to questionable estimates and problematic biases, such as negative or excessively small home ranges (e.g., figure 2 in the work of Bista et al 2022).…”