Hiding in plain sight: risk mitigation by a cryptic carnivore foraging at the urban edge

Abstract

As natural habitat is progressively transformed, effective wildlife conservation relies on understanding the phenotypic traits that allow select species to persist outside of protected areas. Through behavioural flexibility such species may trade off abundant resources with risks, both real and perceived. As highly adaptable mesocarnivores, caracals (Caracal caracal) provide an opportunity to examine development of successful foraging strategies in high‐risk developed areas. Here we investigated caracal resource selection of both anthropogenic and environmental factors relative to availability at varying levels of urbanization in and around the city of Cape Town, South Africa, using GPS cluster‐located feeding events (n = 326 prey remains, n = 384 scat). We also examined spatial and temporal risk mitigation strategies by assessing behaviours at feeding clusters. We find that, within home ranges, caracals living in the urban‐dominated region (n = 14; 548 feeding events) select for the urban edge, while caracals in the wildland‐dominated region (n = 3; 162 feeding events) avoid it. Adults selected more strongly for foraging at the urban edge than juveniles and may competitively exclude them from resources. By including back‐traced scat feeding event locations, we were able to improve model resolution. We argue that caracals foraging on the edge of a large metropole mitigate risk of detection by remaining cryptic, prolonging handling time, and maintaining high feeding site fidelity where cover was available. Along with the strong functional response to the urban edge, this strategy suggests that carnivores are being drawn into, and stay longer in, areas with potentially increased prey availability despite higher risk. While behavioural plasticity clearly enables carnivore coexistence with humans in urban ecosystems, it can also be maladaptive if it reduces fitness and leads the population into an ecological trap. We provide mitigative recommendations to promote the conservation of this predator in a spatially isolated and rapidly urbanizing landscape.

The effect of decreasing human activity from COVID‐19 on the foraging of fallen fruit by omnivores

“…We hypothesized that raccoon dogs and Japanese badgers would shift their temporal activity patterns to be more diurnal when released from competitive pressures of humans due to COVID‐19 restrictions. Mesocarnivores (small‐ to mid‐sized carnivore species) are known to shift their temporal patterns depending on a variety of factors and are often completely nocturnal in urban areas (avoidance of dominant carnivores: Frey et al, 2022 ; Suraci et al, 2021 ; Wang et al, 2015 ; avoidance of humans: Gaynor et al, 2018 ; Riley et al, 2003 ; Tigas et al, 2002 ; prey activity: Leighton et al, 2021 ). We found that raccoon dogs became more diurnal during their foraging behavior with substantial shifts in their activity patterns in 2020, while Japanese badgers exhibited diurnal foraging behavior in 2020 after never exhibiting it in 2019.…”

Poisoned chalice: Use of transformed landscapes associated with increased persistent organic pollutant concentrations and potential immune effects for an adaptable carnivore

“…Next, using data provided under agreements from both Eskom and the City of Cape Town, we calculated the average electrical transformer density and human population density (see Table S2 for landscape covariate information). We calculated 95% LoCoH-a (adaptive) home ranges for animals for which we had a minimum of 30 days of three-hour fix interval movement data (Getz et al 2007) implemented in t-locoh (Lyons et al 2013) as in Leighton et al 2021. For opportunistically sampled caracals (n=31), we calculated these spatial variables within a circular buffer around the GPS location where the animal was found.…”

“…Around the rapidly expanding city of Cape Town, South Africa, caracals (Caracal caracal) selectively forage at the urban edge (Leighton et al 2021) but unwittingly experience pollutant…”

Urban habitat use and home ranges of fishing cats in Colombo, Sri Lanka

“…Our study has provided the first report of urban landscape use by fishing cats, indicating they could be among the felid species that can adapt to a life within cities, rather than remaining at the urban-wildland interface (Leighton et al 2021;Riley et al 2003Riley et al , 2014. While other urban felid studies report human population densities in their study areas, ranging from 471.6 people/km 2 (Texas, USA; Lombardi et al 2017) to 1687.0 people/km 2 (California, USA; Markovchick-Nicholls et al 2008), the human population density in Colombo is 2.1-7.6 times greater (3608 people/km 2 ; Central Bank of Sri Lanka 2019).…”

“…Data download was attempted at a weekly cadence. All collars weighed < 5% of each individual's total body weight, as recommended by other studies (Kenward 2000), and once recovered from immobilisation, all individuals were immediately released into their respective sites.…”