Introduction
Movement behavior is informative in capturing how animals respond to the heterogeneity in their environment. These responses include broad-scale decisions in the size and location of the home range (Burt 1943) as well as finer scale responses to heterogeneity in the environment through habitat selection decisions (Johnson 1980). Animals often vary in their movement behavior, which can be due in part to individual personality (Réale et al. 2010, Kaiser and Müller 2021), or plasticity in individual- or population-level behavior (Stamps and Groothuis 2010, Snell-Rood 2013). This variation can lead to directional reactions of animals to their environment, known as functional responses, which can include reactions to habitat (Mysterud and Ims 1998, Newediuk et al. 2022), prey (Holling 1965), forage (Spalinger and Hobbs 1992), or other stimuli. Functional responses of animal spatial behavior to anthropogenic factors have been documented in various species, including in wolf (Canis lupus ) (Hebblewhite and Merrill 2008), caribou (Rangifer tarandus caribou ) (Moreau et al. 2012), and moose (Alces alces ) (Beyer et al. 2013) habitat selection and proximity to humans. Habitat selection is a particularly informative behavior to study because of the direct link between the spatial choices an individual makes and variability in the environment (Johnson et al. 2002), and because it can have direct implications for an animal’s fitness (Nilsen et al. 2004, Mayor et al. 2009). Habitat selection and functional responses are especially important in the context of anthropogenic change, when landscape compositions are constantly undergoing modifications.
Animals can display a wide range of responses toward anthropogenic factors. These responses can range from generic, or broad-scale (hereafter referred to as generic responses), such as consistently avoiding human activity or structures in their home range (Muhly et al. 2011, Leblond et al. 2013), and which could lead to increased home range size for individuals inhabiting areas with greater levels of human modification (O’Donnell and delBarco-Trillo 2020). At the other end of this gradient, species can display nuanced, or refined, responses (hereafter termed nuanced responses) to humans, such as only avoiding anthropogenic features at a fine scale and during a certain periods of the day (Tigas et al. 2002), seasonally (Johnson et al. 2005), or by using a combination of spatiotemporal responses (Knopff et al. 2014). Investigating individual and temporal variation in spatial behavior can elucidate broader patterns in behavior, linking spatial ecology and animal behavior (Hertel et al. 2020), as well as help draw conclusions about population-level relationships with habitat (Bastille-Rousseau and Wittemyer 2019). Here, we propose that a multi-faceted characterization of a population that includes individual, spatial, and temporal variation in space use form the basis of characterizing where a population or species fall along a “generic-to-nuanced” gradient in spatial responses. This gradient is especially informative in characterizing animal responses to anthropogenic activities, which can also be particularly useful for wide-ranging species which use a variety of habitats with varying levels of human development.
Bobcats (Lynx rufus ) and coyotes (Canis latrans ) are two mesocarnivores that fill the role of top predator in the absence of large predators throughout much of North America (Laliberte and Ripple 2004, Roemer et al. 2009, Lesmeister et al. 2015). Bobcats are strictly carnivorous and are believed to prefer forested habitat above other habitat types (Litvaitis and Harrison 1989, Lesmeister et al. 2015). Coyotes are more generalist in both diet and habitat and are found in all habitats along a forested-to-rural gradient (Randa and Yunger 2006, Lesmeister et al. 2015), and are more likely than bobcats to exploit agricultural landscapes (Litvaitis and Harrison 1989, Nielsen et al. 2017). Both bobcats and coyotes have been observed to expand their home range with increased fragmentation, but coyotes are more plastic and adaptable to anthropogenic change, exploiting small resource patches on a landscape scale, regardless of connection (Riley et al. 2003, Atwood et al. 2004). Although mesocarnivores are a group expected to adapt better than other species to human development (Červinka et al. 2014, Streicher et al. 2021), they experience a spectrum of adaptability to coexistence with humans based on flexibility in diet and suitable habitat, as well as plasticity in behaviors like boldness and neophilia, leading to a variety of responses to anthropogenic land modification (Réale et al. 2007, Mason et al. 2013).
Here we studied how variation in anthropogenic activity shapes movement behaviors of these mesocarnivore species and characterized where they belong on the “generic-to-nuanced” gradient. Specifically, we investigated how a gradient of human modification impacted home range size and habitat selection of both species. We also evaluated how habitat selection behaviors vary temporally and how individual variation in this behavior could be linked to variation to the intensity of human modification for an individual (functional response). Overall, given the behavior of both mesocarnivores, we expected bobcat responses to be on the generic end of the gradient, marked by stronger and more consistent avoidance of human activities and overall larger home range when exposed to human activities. Meanwhile, we expected coyote responses to be more nuanced, with home-ranging behaviors less affected by human modification, but with space-use showing more individual variation, temporally-acute selection behaviors, and complexity in their functional responses to human modification.