Could an increase in the numbers of threatened lions have an impact on endangered Grevy’s zebras?
Researchers in Laikipa County, Kenya, focused on this very question in a recent study, the findings of which have been published in the open-access journal PLOS ONE.
The study team from the World Conservation Society and World Wildlife Fund set out to discover whether the comeback of a top predator, in this case lions in Laikipa County, were recovering at the expense of Grevy’s zebras, which number only around 2680 individuals, half of which live in the county.
In recent years, lion numbers have slowly recovered in this region as livestock ranching, which commonly practiced shooting or poisoning lions, has given way to wildlife tourism.
Lions are classified as threatened by the International Union for Conservation of Nature (IUCN).
The team used satellite telemetry to track the movements of both lions and zebras.
The researchers found that lions preyed on both Grevy’s and plains zebras (Equus quagga) far less than expected.
Their data showed that the population of Grevy’s zebra populations may in fact be stabilizing, with recruitment into the population tripling since 2004.
The researchers did conclude that competitive displacement by livestock and interference competition for grass from plains zebras, which are 22 times more abundant than Grevy’s, are most likely the predominant threat to Grevy’s zebras’ recovery.
The full study team comprised Timothy O’Brien, Margaret Kinnaird, Steven Ekwanga, Christopher Wilmers, Terrie Williams, Alayne Oriol-Cotterill, Daniel Rubenstein and Laurence Frank.
O’Brien TG, Kinnaird MF, Ekwanga S, Wilmers C, Williams T, Oriol-Cotterill A, et al. (2018) Resolving a conservation dilemma: Vulnerable lions eating endangered zebras. PLoS ONE 13(8): e0201983. https://doi.org/10.1371/journal.pone.0201983