Hunger mediates apex predator's risk avoidance response in wildland–urban interface

Abstract

Conflicts between large mammalian predators and humans present a challenge to conservation efforts, as these events drive human attitudes and policies concerning predator species. Unfortunately, generalities portrayed in many empirical carnivore landscape selection studies do not provide an explanation for a predator's occasional use of residential development preceding a carnivore-human conflict event. In some cases, predators may perceive residential development as a risk-reward trade-off. We examine whether state-dependent mortality risk-sensitive foraging can explain an apex carnivore's (Puma concolor) occasional utilization of residential areas. We assess whether puma balance the risk and rewards in a system characterized by a gradient of housing densities ranging from wildland to suburban. Puma GPS location data, characterized as hunting and feeding locations, were used to assess landscape variables governing hunting success and hunting site selection. Hunting site selection behaviour was then analysed conditional on indicators of hunger state. Residential development provided a high energetic reward to puma based on increases in prey availability and hunting success rates associated with increased housing density. Despite a higher energetic reward, hunting site selection analysis indicated that pumas generally avoided residential development, a landscape type attributed with higher puma mortality risk. However, when a puma experienced periods of extended hunger, risk avoidance behaviour towards housing waned. This study demonstrates that an apex carnivore faces a trade-off between acquiring energetic rewards and avoiding risks associated with human housing. Periods of hunger can help explain an apex predator's occasional use of developed landscapes and thus the rare conflicts in the wildland-urban interface. Apex carnivore movement behaviours in relation to human conflicts are best understood as a three-player community-level interaction incorporating wild prey distribution.

Hunger makes apex predators do risky things

“… Abstract In Focus: Puma ( Puma concolor ), an apex predator, can live at the edge of cities where pockets of low‐density human dwellings form residential patches in the wildland–urban interface. Blecha, Boone, and Alldredge () tracked puma via global positioning system ( GPS ) telemetry collars to determine when and where they hunted and made kills. Well‐fed puma (1–2 days between kills) strongly avoided residential patches despite these areas having higher mule deer ( Odocoileus hemionus ) densities and higher kill success for puma.…”

“…Blecha et al. () explore some of these issues in a system where puma, an apex predator, live near cities surrounded by “exurban” areas characterized by patches of low‐density human housing intermixed with wildland habitat (Figure ). They equipped puma with GPS telemetry collars to obtain locations of where individuals spent their time.…”

“…Blecha et al. () added an innovative twist to their analysis. Given they could determine the time and location of kills, they could also look at the choices made by puma as they became hungrier (time since last kill increased).…”

“…Blecha et al. () have provided a simple solution. It has become standard practice to determine large carnivore kill sites by the spatial and temporal clustering of telemetry locations (Merrill et al., ; Webb, Hebblewhite, & Merrill, ), and this will become increasingly sophisticated with the incorporation of accelerometer (Blecha & Alldredge, ), video (Brockman, Collins, Welker, Spalinger, & Dale, ) and audio devices on telemetry collars.…”

“…However, in the meantime, Blecha et al. () have provided a first step to incorporate the internal state of an organism into animal movement models, an important next step in the emerging field of movement ecology (Nathan et al., ).…”