Mountain lions are eating California wild donkeys. Why scientists say this is a good thing
California wild donkeys (Equus asinus spp.) are migrating on the Pacific Coast. They are eating the wild horses who cross their path. That’s good news for the California wild horse population, if the California Department of Fish and Wildlife is to be believed.
But scientists at the University of California say the two aren’t really that similar after all, and that’s why they’re able to eat one another.
“The difference between wild horse and donkey is that the donkey is the more diverse subspecies, with the different subspecies having been interbred for generations,” said Alan Lopatto, a UC ecologist who led the study. Lopatto is professor of population and community ecology and director of the Conservation Ecology Program at UC Davis — a program that looks at how animals adapt to changing environments.
Wild horses roam from the northern Great Plains to the southern Sierra Nevada. The California wild donkeys eat grass, browse on trees, and occasionally eat plants other than the grass. But they do not like eating the other animals in the herd.
The California wild donkey is a hybrid of the California and American donkeys. Their genes are similar enough they can breed, but the American donkey has much more variation in its genetic makeup than the California donkey.
Lopatto studied how this interbreeding occurs over time, in hopes of understanding how the different subspecies of wild horse evolve. He and his co-authors looked at a group of wild horses that had been living in California for about 50 years, and then studied its wild donkey population. He found that the California wild donkeys no longer eat other wild donkeys, because the other donkeys no longer eat them.
“That really supports the hypothesis that these two species have become distinct species,” Lopatto said.
The researchers did not say how
