Testing Predictions of the Prey of Lion Derived From Modeled Prey Preferences

Abstract

Apex predators are often threatened with extinction, and reintroduction is one method conservation managers are using to secure their persistence. Yet the ability to predict what these predators will eat upon reintroduction is lacking. Here we test predictions of the diet of the lion (Panthera leo), derived from dietary electivity index and optimality theory, using independent data collected from reintroduced and resident populations. We solved the Jacobs’ index preference equation for each prey species of the lion using values calculated by Hayward and Kerley (2005) and prey abundance data from 4 reintroduction sites and one resident lion population over several years. We then compared these estimates with actual kill data gathered from each site and time period, using the log‐likelihood ratio and linear regression. The model precisely predicted the observed number of kills in 9 of the 13 tests. There was a highly significant linear relationship between the number of lion kills predicted to occur at a site and the number observed for all but one site (x̄r2 = 0.612; β = 1.03). Predicting predator diet will allow conservation managers to stop responding and start planning in advance for reintroductions and environmental variation. Furthermore, ensuring that sufficient food resources are available is likely to increase the success of reintroduction projects. In addition, managers responsible for threatened prey species will be able to predict the vulnerability of these species to predation in the event of predator reintroductions or changes in abundance. These methods are applicable to virtually all large predators that have been sufficiently studied.

The Influence of Large Predators on the Feeding Ecology of Two African Mesocarnivores: The Black-Backed Jackal and the Brown Hyaena

“…These reintroductions have provided aframework within whichimpacts of apex predators on ecosystem dynamics can be tested experimentally. While the impacts of apex predators on prey species have been well documented (Power 2003;Hayward et al 2007b;Hayward, O'Brien & Kerley 2007;Lehmann et al 2008), their influence on the foraging ecology of other carnivores in fenced reserves is not fully understood (Hayward & Kerley 2009;Brassine & Parker 2012). Moreover, very little is known about interspecific interactions between mesocarnivores and large apex predators in South Africa prior to the extirpation of the latter.…”

Lion hunting behaviour and vegetation structure in an African savanna

“…Several recent studies have begun to explore the role of spatial heterogeneity in shaping the distribution of predatoreprey interactions across landscapes (Hopcraft et al 2005;Valeix et al 2009). For example, the decline of roan, Hippotragus equinus, and other antelope that tolerate sparse surface water to avoid high predator densities has been partially attributed to lions following water-dependent antelope into arid landscapes after the construction of waterholes (Grant et al 2007;Hayward et al 2007). How spatial heterogeneity in vegetation structure influences predatoreprey interactions is less well understood.…”

Practical Considerations for the Reintroduction of Large, Terrestrial,Mammalian Predators Based on Reintroductions to South Africa's Eastern Cape Province

“…The principal cause of most species' decline is the loss and alteration of habitat [45,52]. For large carnivores this is less likely than for other species, as prey availability is more important than the vegetation characteristics of a site [42,53,54]. Hence, if there is suitable prey available [23,[55][56][57][58], adequate refuges for competitively-inferior predators to escape persecution and kleptoparasitism from larger predators [59] and measures to alleviate human -wildlife conflict [15], then all large predator reintroductions are likely to be successful.…”

“…Coalitions of male lions have been removed at several sites, however this may mean that the anti-predator strategy of large prey species, like buffalo and giraffe, becomes redundant and may weaken the herd via the retention of genes that would otherwise have been selected out of the population. Conversely it seems unlikely that such management will result in an alteration of the lions' predatory instinct given that those reintroduced to Addo from the buffalo-free Kalahari took less than one year to learn how to hunt buffalo successfully [42]. Even the frequent management practice of maintaining coalitions of male lions is unusual in more natural ecosystems where coalition sizes range up to nine [65].…”