Predation risk constrains herbivores’ adaptive capacity to warming

Abstract

Life sciences study designAll studies must disclose on these points even when the disclosure is negative. Sample sizeNo sample-size calculation was performed. We used camera trap data from 32 different protected areas in which about half lions were present. This is far beyond the sample sizes used in any study so far on herbivore behavior in response to predation risk. To calculate activitity patterns for each herbivore species, we set the sample size threshold at 100 captures per species per survey to increase the robustness of our estimates. Decreasing this threshold did not qualitatively change our results.Data exclusions We set the sample size threshold at 100 captures per species per survey to increase the robustness of our estimates. Decreasing this threshold did not qualitatively change our results. Thus, species with less than 100 captures were excluded. ReplicationThe design included replication of predator presence and absence, with 16 areas (replications) of lion presence and 16 areas (replications) of lion absence.Randomization Allocation of predator or herbivore presence was not done randomly, but based on natural occurence of herbivores and reintroduction of lions in protected area across South Africa. Nevertheless, this comes very close to a "natural experiment" as lions used to be present in all 32 protected areas and there is no bias in environmental characteristics (temperature, rainfall) between areas with and without lions present. BlindingData collection was done via camera traps so this could be seen as "blind" data collection for the purpose of this study. Reporting for specific materials, systems and methodsWe require information from authors about some types of materials, experimental systems and methods used in many studies. Here, indicate whether each material, system or method listed is relevant to your study. If you are not sure if a list item applies to your research, read the appropriate section before selecting a response.

Spatial heterogeneity facilitates carnivore coexistence

“…However, our results do suggest that wild dogs in HiP might begin hunting earlier than elsewhere, and the afternoon peak in movement rate could represent altered activity budgets in this high-lion-density environment. Wild dogs shift their activity to nighttime in areas of high human density (Rasmussen and Macdonald 2012) and it is possible that the afternoon peak in activity represents a behavioral modification to avoid lions, as has been documented for prey species (Tambling et al 2015, Veldhuis et al 2020.…”

The impacts of heat stress on animal cognition: Implications for adaptation to a changing climate

“…However, foraging at night can increase the exposure to nocturnal predators. For example, in the presence of lions ( Panthera leo ) ungulates are more likely to forage during the day under suboptimal temperatures (Veldhuis et al, 2020). Foraging in the heat can be less efficient due to heat dissipation: in Southern pied babblers ( Turdoides bicolor ) when daily temperature exceeds 35.5°C, panting hinders digging behavior and prey manipulation, leading to body mass loss (du Plessis et al, 2012), and reduced provisioning rates (Wiley & Ridley, 2016).…”

Predator presence and recent climatic warming raise body temperatures of island lizards

“…2015; Veldhuis et al . 2020). Yet a common expectation for lizard species is for body temperatures to be lower under higher predation pressure due to the heightened risks of behavioural thermoregulation (Huey & Slatkin 1976; Salazar et al .…”

“…Conversely, prey activity windows can also be more restricted to the hottest times of day, and thus less flexible to respond to warming because of predators hunting during cooler hours (Veldhuis et al . 2020). Changes in the temporal and spatial occupancy of thermal habitats by both prey and predator, and the ways in which they compound and affect one another, thus need to be jointly considered in order to adequately estimate climate change responses (Schmitz & Barton 2014) for effective comparisons with systems free of predation.…”