The relative effects of prey availability, anthropogenic pressure and environmental variables on lion (Panthera leo) site use in Tanzania's Ruaha landscape during the dry season

Abstract

African lion (Panthera leo) populations have been reduced by almost half in the past two decades, with national parks and game reserves maintaining vital source populations, particularly in East Africa. However, much of the habitats necessary to support lion populations occur in unprotected lands surrounding protected areas. There is an ongoing need for understanding the ecological determinants of lion occurrence in these unprotected habitats, where lions are most vulnerable to extinction. This study evaluated variations in lion site use along a gradient of anthropogenic pressure encompassing the Ruaha National Park, Pawaga‐Idodi Wildlife Management Area (WMA) and unprotected village lands via camera‐trapping. We collected lion occurrence data in the dry seasons of 2014 and 2015, and modelled lion site use as a function of environmental and anthropogenic variables under a Bayesian framework. We recorded 143 lion detections within the national park, 14 in the WMA and no detections in village lands. This result does not imply that lions never use the village lands, but rather that we did not detect them in our surveys during the dry season. Our findings suggest that lion site use was primarily associated with high seasonal wild prey biomass in protected areas. Thus, we infer that human‐induced prey depletion and lion mortality are compromising lion site use of village lands. Seasonal prey movements, and a corresponding concentration inside the park during sampling, could also play an important role in lion site use. These findings reinforce the need to secure large‐bodied prey base to conserve lions, and the importance of protected areas as key refugia for the species.

Environmental and anthropogenic factors synergistically affect space use of jaguars

“…May Jú nior, 5,17,18,37 George V.N. Powell, 38 Mathias W. Tobler, 39 Samia E. Carrillo-Percastegui, 39 Estebá n Payá n, 18 Fernando C.C. Azevedo, 5,40 Henrique V.B.…”

“…Decreasing home range size in relation to increasing forest cover and ecosystem productivity is attributable to greater availability of preferred habitat and prey, which reduces spatial needs to meet metabolic and reproductive requirements. 16,32,34 Increasing road density can affect jaguars and other large cats 33,[35][36][37][38][39][40][41] through direct human mortality (hunting, vehicle collisions) or through prey reduction, while driving behavioral changes related to human presence and land use to avoid or use areas of greater risk, which increases costs to movements and increases spatial needs. We recognize that greater forest cover and net primary productivity do not necessarily translate to greater prey availability since in tropical humid forests in particular, biomass is concentrated in the canopy, 42,43 which in part explains jaguars' association with rivers in these systems 11,44 and the relatively large estimated home ranges in the Southwest Amazon and Pet en-Veracruz moist forest where forest cover and productivity are comparatively high (Table S5).…”

Temporal partitioning and spatiotemporal avoidance among large carnivores in a human-impacted African landscape

“…Although lion population density was higher in MBOMIPA WMA (4.06 ± 1.03 per 100 km 2 ) than the miombo woodland of Rungwa GR (2.25 ± 0.52 per 100 km 2 ) and Ruaha NP (1.75 ± 0.62 per 100 km 2 ; see S8 File), there appears to be a strong density gradient within the WMA, with 93% of lion detections in this site occurring within 5 km of the Great Ruaha River, further from the boundary with unprotected village land (see S5.1B Fig in S5 File). It is also highly probable that lion persist at very low densities in unprotected village land, as a result of widespread habitat conversion and degradation, low prey availability, and high anthropogenic mortality [57]. In these areas, lion densities may therefore be sufficiently low that leopard no longer need to adjust their activity patterns to avoid harmful interactions with lion-particularly as this would increase their exposure to humans-and can instead rely more heavily on reactive avoidance strategies [9].…”

The efficacy of interventions to protect crops from raiding elephants

“…They can be as seemingly benign as raccoons (Procyon lotor) denning in suburban American homes to as severe as hyenas African lions (Panthera leo) killing livestock or harming people in sub-Saharan Africa (O'Donnell and DeNicola 2006). Despite this diversity, conflict tends to be most damaging for people and, correspondingly intense for wildlife, when the interactions involve large mammals (Choudhury 2004;Kolowski and Holekamp 2006;Hegel et al 2009;Abade et al 2019). Species in the order Carnivora, infra-order Ungulata, and order Proboscidea, for instance, have been disproportionately persecuted by humans in response to real or perceived conflict (Cardillo et al 2006;Darimont et al 2009;Chapron et al 2014;Montgomery et al 2020a).…”