Discovery Files

Belly up to the bamboo buffet: Pandas vs. horses

Livestock, particularly horses, have been identified as a significant threat to panda survival

2014 is the Year of the Horse in China. But pandas, it turns out, aren't celebrating

Why not? Because livestock, particularly horses, have been identified as a significant threat to panda survival. The reason: Horses have been beating pandas to the bamboo buffet. The oft-hidden, yet significant, conservation conflict between pandas and horses was revealed in a recent article in the Journal for Nature Conservation by Michigan State University (MSU) panda habitat experts.

"Across the world, people are struggling to survive in the same areas as endangered animals, and often trouble surfaces in areas we aren't anticipating," said Jianguo "Jack" Liu of MSU. "Creating and maintaining successful conservation policy means constantly looking for breakdowns in the system. In this case, something as innocuous as a horse can be a big problem."

Pandas have specific habitat needs--they live in gently sloping areas far from human populations. And they only eat bamboo. (Watch a panda bellying up to the bamboo buffet.) China invests billions to protect its panda habitat and conserve the 1,600 remaining endangered supported by this habitat.

For years, timber harvesting has been the panda's biggest threat. But conservation programs limiting timber harvesting have chalked up wins in preserving panda habitat.

Vanessa Hull, a doctoral student at MSU's Center for Systems Integration and Sustainability (CSIS), has been living off and on for seven years in the Wolong Nature Reserve, most recently tracking pandas that she has outfitted with GPS collars.

Over the years, she started noticing that uninvited guests had apparently been serving themselves at the bamboo buffet--and they were eating like horses…literally.

"It didn't take particular panda expertise to know that something was amiss when we'd come upon horse-affected bamboo patches. They were in the middle of nowhere and it looked like someone had been in there with a lawn mower," Hull said.

Alarmed by the increasing devastation, Hull learned that keeping a horse in this region serves a similar function as maintaining a bank account. Because horses are prohibited from grazing in designated grazing areas, to prevent them from competing for food with cattle, some farmers have been letting horses graze unattended in forests. When these horse-keeping farmers need cash, they track down their horses in the forest and sell them.

Eventually, some Wolong farmers, though not traditionally horse-keepers, learned from horse-keeping friends who lived outside of the reserve that they too could cash in by keeping horses--and letting them loose to graze unattended in Wolong. Where, unfortunately, they would compete for food with pandas.

Over time, the popularity of this practice soared. In 1998, only 25 horses lived in Wolong. By 2008, 350 horses lived there in 20 to 30 herds.

To understand the scope of the problem, Hull and her colleagues put the same type of GPS collars they were using to track pandas on one horse in each of four herds they studied. Then, over a year they compared the activity of the horses with that of three collared adult pandas in some of the same areas, and combined resulting data with habitat data.

The researchers discovered that the galloping gourmets are indeed big on bamboo--and are drawn to the same sunny, gently sloped spots as pandas. Pandas and horses eat about the same amount of bamboo, but a herd of more than 20 horses created veritable feeding frenzies, destroying areas that the reserve was established to protect.

The researchers presented their findings to Wolong's managers, who have since banned horses from the reserve. But Hull and Liu note that this work has shed light on how competitive livestock can be in sensitive habitat--an issue that is duplicated across the globe.

"Livestock affect most of the world's biodiversity hotspots," Liu said. "They make up 20 percent of all of the earth's land mammals and therefore monopolize key resources needed to maintain the earth's fragile ecosystems."

This research project received funding from the National Science Foundation.

Editor's Note: This Behind the Scenes article was first provided to LiveScience in partnership with the National Science Foundation.