A new study, led by Dr Vanessa Hull of the Michigan State University’s Center for Systems Integration and Sustainability, has revealed more details on how endangered giant pandas (Ailuropoda melanoleuca) spend their time in the Chinese bamboo forests.
Giant panda cub Xiao Liwu and his mother Bai Yun at the San Diego Zoo.
Five pandas – three female adults named Pan Pan, Mei Mei and Zhong Zhong, a young female Long Long and a male dubbed Chuan Chuan – were captured, collared with GPS collars and tracked from 2010 to 2012, in the Wolong Nature Reserve in southwest China.
“Pandas are such an elusive species and it’s very hard to observe them in wild, so we haven’t had a good picture of where they are from one day to the next,” said Dr Hull, who is the first author of the paper published in the Journal of Mammalogy.
“This was a great opportunity to get a peek into the panda’s secretive society that has been closed off to us in the past,” said Dr Jindong Zhang, also of the Center for Systems Integration and Sustainability.
“Once we got all the data in the computer we could see where they go and map it. It was so fascinating to sit down and watch their whole year unfold before you like a little window into their world.”
According to the scientists, the pandas seem to hang together sometimes. Usually renowned for being loners, three in the group (Chuan Chuan, Mei Mei and Long Long) were found to be in the same part of the forest at the same time – for several weeks in the fall and outside the usual spring mating season.
“We can see it clearly wasn’t just a fluke, we could see they were in the same locations, which we never would have expected for that length of time and at that time of year,” Dr Hull said.
Dr Zhang added: “this might be evidence that pandas are not as solitary as once widely believed,”
Chuan Chuan moseyed across a bigger range than any of the females, leading the team to speculate that he spent time checking in on the surrounding females and advertising his presence with scent marking – rubbing stinky glands against trees.
The scientists also learned about a panda’s feeding strategy from this surveillance period.
Many animals in the wild have a home range, and within that a core area they frequently return to and defend. Pandas, according to the study, have from 20 to 30 core areas, which might be a reflection of their feeding strategy.
“They pretty much sit down and eat their way out of an area, but then need to move on to the next place,” Dr Hull said.
It’s been known that pandas follow bamboo – the food that makes up virtually all of their diet. Once they munch through one patch they move to the next, which accounts for a lot of their territory.
“But what this peek into their world revealed is that the pandas returned to core areas after being gone for long spans of time – up to 6 months,” Dr Hull said.
“It suggests the pandas do remember successful dining experiences, and return in anticipation of regrowth. Specific locations may also have other importance for pandas to return to if they are communicating with neighboring pandas at certain vantage points.”
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Vanessa Hull et al. 2015. Space use by endangered giant pandas. Journal of Mammalogy, vol. 96, no. 1; doi: 10.1093/jmammal/gyu031
