Donkey kingdom
Researchers studying wild burros in hopes to improve coexistence
ENVIRONMENT
For students at University of California, Riverside, the start of fall semester meant picking up their class syllabus, catching up with friends and snapping selfies with the wild donkeys that roam around the school.
The hoofed Highlanders are embraced as an unofficial campus mascot, with social media threads dedicated to donkey spotting and burro plushies for sale in the campus store.
The animals' relationship with residents in nearby communities of the Inland Empire region is more complicated.
Though many residents love the wild burros, others see them as a public safety risk due to the possibility of car crashes, property damage or injuries during encounters.
When it comes to decisions about how best to manage the population, tensions often run high.
A community firestorm erupted after San Bernardino County contracted with a nonprofit to relocate hundreds of wild donkeys to a Texas sanctuary, resulting in death threats against the nonprofit's leader and ultimately leading officials to terminate the agreement last year.
Reports that at least half a dozen donkeys were shot with arrows — attacks that are unsolved — sparked outrage this year.
Mysteries of the herd
Little is known about the herd, so a team of researchers at UC Riverside is on a mission to study the wild population in hopes of gaining insights that can improve coexistence between humans and donkeys.
"Donkeys are very strong animals; they bite, they kick," associate professor Marko Spasojevic said. "We want to avoid those conflicts by better understanding where they go, what resources they need and ideally help Riverside County take care of these populations."
Spasojevic, who teaches in the Department of Evolution, Ecology and Organismal Biology, leads the university's research on the donkey herd. One of the first tasks is to gain a precise understanding of the herd's population size and birth trends.
Several hundred donkeys are thought to live in the Box Springs Mountain Reserve and are known to wander into the nearby communities, he said.
As temperatures spike and vegetation dries in the summer and fall, donkeys often travel down the hillside to graze on UC Riverside's irrigated lawns or enjoy a nap in the cool shade of the parking structures.
Graduate student Wyatt Hall is deploying motion-activated wildlife cameras across the burros' habitat to help track and count the population.
"Understanding how quickly that population is growing will help us think about things like minimizing traffic collisions," Spasojevic said. "If the population is growing a lot, we may need to think about putting in barriers or wildlife overpasses."
Ecological effects
Another long-term goal of UC Riverside researchers is to understand the ecological role and effects of the herd.
Based on observations thus far, Spasojevic believes the burros could play an important role in the ecosystem by grazing on non-native grasses, preventing them from overtaking native plants. Still, he's concerned the animals' trails could cause damaging levels of soil erosion.
To learn more about their feeding habits, researchers plan to analyze poop samples. In future years, Spasojevic also would like to put GPS collars on wild donkeys to better understand their movement.
This year, he and colleagues Ellie Armstrong and Kieran Samuk also plan to use genetic technology to try to understand the origin of the herd.
Scientists traced the origins of donkeys back more than 5,000 years to eastern Africa. The animals reached Spain during the Roman Empire, and Spanish colonists brought the animals to what is now Mexico in the 1500s. In the 1770s, Spanish explorer Juan Bautista de Anza led an expedition of settlers into what later became California, bringing donkeys and horses with him.
There are two predominant rumors about how a wild herd ended up in the Inland Empire, Spasojevic said. The first is that miners abandoned donkeys in the region during the gold rush; the second is that a group of ranchers drove over a population of burros from Death Valley in the 1950s.
Spasojevic hopes to gain a clearer answer by comparing DNA samples from these donkeys to DNA collected from populations elsewhere.
One thing unique about this wild donkey population is its proximity to urban areas.
"Most of the places where there are large populations are places like Arizona where they're out in open wildlands," Spasojevic said. "Here we have them walking through neighborhoods."
On campus, students are educated on the importance of not touching or feeding the donkeys, which weigh about 500 pounds and, when they feel threatened, can charge at humans. Students also are instructed to slow down when driving near donkeys as collisions can cause injury or death to humans and animals.
