Humans disrupt access to prey for large African carnivores

Abstract

Wildlife respond to human presence by adjusting their temporal niche, possibly modifying encounter rates among species and trophic dynamics that structure communities. We assessed wildlife diel activity responses to human presence and consequential changes in predator-prey overlap using 11,111 detections of 3 large carnivores and 11 ungulates across 21,430 camera trap-nights in West Africa. Over two-thirds of species exhibited diel responses to mainly diurnal human presence, with ungulate nocturnal activity increasing by 7.1%. Rather than traditional pairwise predator-prey diel comparisons, we considered spatiotemporally explicit predator access to several prey resources to evaluate community-level trophic responses to human presence. Although leopard prey access was not affected by humans, lion and spotted hyena access to three prey species significantly increased when prey increased their nocturnal activity to avoid humans. Human presence considerably influenced the composition of available prey, with implications for prey selection, demonstrating how humans perturb ecological processes via behavioral modifications.

Diurnal pastoralism does not reduce juvenile recruitment nor elevate allostatic load in spotted hyenas

“…Furthermore, over the course of our study, the hyena population was recovering from a major decline (Höner et al, 2005) and therefore likely experienced little competition for prey. Consistently abundant prey may also explain why there was no detectable effect of prey per capita on juvenile recruitment, in stark contrast to other studies (Broekhuis et al, 2021;Mills & Harris, 2020). Even if prey per capita within a clan territory declined greatly, there would be plentiful prey in other clan territories that hyenas could access by intruding (Höner et al, 2005).…”

Mammals adjust diel activity across gradients of urbanization

“…While human population densities increased nocturnal activity for coyote, it decreased nocturnal activity for white-tailed deer, eastern cottontail, and raccoon. Prey species may become more diurnal to avoid increased activity in nocturnal predators ( Mills and Harris, 2020 ) or they may be utilizing increased human activity during daytime hours as a human-mediated shield. Prey species are known to spatially distribute themselves near human activity to act as a shield from predators ( Berger, 2007 ; Shannon et al, 2014 ).…”

The influence of human activity on predator–prey spatiotemporal overlap

“…Human activity may influence prey choice, for example, when predators have multiple prey, or reshape multi‐predator effects on prey with more than one predator (Sih et al, 1998). To advance predictions of how human activity will affect species interactions, it will be beneficial to apply this framework to combinations of predators, prey, and competitors (Mills & Harris, 2020). One promising avenue of research lies in comparing how species richness, composition, and food web structure influence predator–prey responses to human activity (e.g.…”