A unique glimpse into the secret life of pandas suggests that the reclusive animals are more sociable than was previously thought.
Scientists tracked five pandas in the wild at the Wolong nature reserve in south-west China for two years after fitting them with GPS collars.
One of the biggest surprises was the degree to which the animals enjoyed hanging out together.
Pandas are renowned for being loners. But three of the group, a male named Chuan Chuan, an adult female named Mei Mei and a young female named Long Long, stayed together in the same area for several weeks in the autumn, outside the usual mating season.
Dr Vanessa Hull, from Michigan State University, US, said: "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."
Colleague Dr Jihong Zhang, also from Michigan State, added: "This might be evidence that pandas are not as solitary as once widely believed."
The study also offered insights into pandas' feeding habits as they munched their way through large quantities of bamboo, which makes up virtually the whole of their diet.
"They pretty much sit down and eat their way out of an area, but then need to move on to the next place," said Dr Hull.
The animals had as many as 20 or 30 "core areas" in their home territory and returned to favourite spots after being gone for long periods of time - as much as six months.
This suggests that pandas remember good food locations and return to them after waiting for the bamboo to regrow.
Specific sites may also be important to pandas if they provide vantage points from which to communicate with their neighbours, the researchers believe.
Dr Hull said: "Pandas are such an elusive species and it's very hard to observe them in the wild, so we haven't had a good picture of where they are from one day to the next.
"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."
There are about 1,864 pandas in the wild and their numbers are said to have increased by 17% since 2003.
But habitat damage and climate change are still casting a shadow over the panda's future, experts fear.
The research is published in the Journal of Mammalogy.