Low apex carnivore density does not release a subordinate competitor when driven by prey depletion

An integrated population model reveals source‐sink dynamics for competitively subordinate African wild dogs linked to anthropogenic prey depletion

“…Below the tipping point, wild dog density should decrease as prey density decreases, because the costs of prey depletion must eventually outweigh the benefits of competitive release. A recent meta-analysis supports this tippingpoint hypothesis (Creel et al, 2023), and recent field studies suggest that prey density has dropped below the tipping point in some ecosystems, for example in the Greater Kafue Ecosystem, where wild dog density is very low (<1/100 km 2 ) even though the density of dominant competitors is also low, as a consequence of prey depletion (Creel et al, 2018;Goodheart et al, 2021Goodheart et al, , 2022Vinks et al, 2020).…”

“…Field studies have consistently shown that African wild dog density correlates negatively with the densities of lions and spotted hyenas (Crocuta crocuta), both within and between ecosystems (Creel & Creel, 2002;Goodheart et al, 2021). Because lion and hyena densities correlate positively with prey density (Hatton et al, 2015), wild dog density should increase as prey density decreases, as long as the benefits of competitive release outweigh the costs of low prey availability (Goodheart et al, 2021). However, large herbivore populations are declining substantially across sub-Saharan Africa due to illegal hunting, competition with livestock and land conversion (Bolger et al, 2008;Goheen et al, 2018;Morrison & Bolger, 2014;Ripple et al, 2015Ripple et al, , 2016Venter et al, 2016;Watson et al, 2013Watson et al, , 2015Western et al, 2009), and the benefits of competitive release must eventually be overwhelmed by the costs of prey depletion; as prey density approaches zero, wild dog density must also approach zero.…”

“…Because apex carnivores are competitively dominant and exploit areas with high prey density, competitively subordinate species like the African wild dog ( Lycaon pictus ) and cheetah ( Acinonyx jubatus ) must optimize a trade‐off between avoiding dominant competitors and maintaining access to prey (Bhandari et al., 2021; Broekhuis et al., 2013; Creel et al., 2023; Creel & Creel, 1996; Dröge et al., 2017; Durant, 2000; Groom et al., 2017; Mills & Gorman, 1997; Swanson et al., 2014). Field studies have consistently shown that African wild dog density correlates negatively with the densities of lions and spotted hyenas ( Crocuta crocuta ), both within and between ecosystems (Creel & Creel, 2002; Goodheart et al., 2021). Because lion and hyena densities correlate positively with prey density (Hatton et al., 2015), wild dog density should increase as prey density decreases, as long as the benefits of competitive release outweigh the costs of low prey availability (Goodheart et al., 2021).…”

“…Field studies have consistently shown that African wild dog density correlates negatively with the densities of lions and spotted hyenas ( Crocuta crocuta ), both within and between ecosystems (Creel & Creel, 2002; Goodheart et al., 2021). Because lion and hyena densities correlate positively with prey density (Hatton et al., 2015), wild dog density should increase as prey density decreases, as long as the benefits of competitive release outweigh the costs of low prey availability (Goodheart et al., 2021).…”

“…However, large herbivore populations are declining substantially across sub‐Saharan Africa due to illegal hunting, competition with livestock and land conversion (Bolger et al., 2008; Goheen et al., 2018; Morrison & Bolger, 2014; Ripple et al., 2015, 2016; Venter et al., 2016; Watson et al., 2013, 2015; Western et al., 2009), and the benefits of competitive release must eventually be overwhelmed by the costs of prey depletion; as prey density approaches zero, wild dog density must also approach zero. This suggests that a tipping point should be expected in the relationship of wild dog density to prey density (Creel et al., 2023; Goodheart et al., 2021). Above the tipping point, wild dog density should increase as prey density decreases, because the benefits of competitive release outweigh the costs of prey depletion.…”