“For 30 years I've been giving talks about pikas and telling the story of how the American pika collects marmot scat in its hay piles, in hopes that someone in the audience will tell me why,” Chris Ray, a quantitative ecologist at the University of Colorado Boulder, says in an email.More than 15 species of rabbits, pikas and hares, collectively referred to as lagomorphs, are widely distributed across North America. ![]() “However, things are changing, and more recent attempts to control them have investigated the use of contraceptives, which have less collateral damage” to other species, he adds. Livestock herders see pikas as direct competitors for food and poison the animals by the millions, Speakman says. ![]() (Read how wild yaks may be climbing higher due to climate change.)Ĭoprophagy may also explain why plateau pikas tend to be more plentiful in areas inhabited by yaks. Taken together, these various pieces of evidence confirm the coprophagy. ![]() In 20, the scientists captured hand-held video of plateau pikas eating yak droppings on four separate occasions. This is probably an underestimate because DNA degrades when feces sit in the sun, he says.Īnother series of tests revealed that in the winter, the makeup of pikas’ microbiomes shift to resemble those of the yaks’-suggesting that the animals may be also acquiring beneficial bacteria from yak feces. To prove the theory, Speakman and colleagues analyzed gut contents of more than 300 deceased plateau pikas-collected for another study in 20-and found that around 22 percent of the sample contained yak DNA. Maybe they eat this stuff." Then a year later, when two pika died accidentally in a trap, an analysis of their gut revealed the presence of yak feces. "Then I really started to think: That's strange. In 2009, Speakman found a half-eaten yak dropping inside a plateau pika’s burrow, triggering his curiosity. Speakman believes yak waste is likely an ample, low-effort food source that allows pikas both to save energy and to stay hidden from predators, such as peregrine falcons and Tibetan foxes. This behavior, known as interspecific coprophagy, is quite rare among vertebrates. “The accumulated evidence, however, is now incontrovertible,” says Speakman, whose study was published today in the Proceedings of the National Academy of Sciences. “At first nobody we spoke to believed the story about them eating the yak feces,” says study leader John Speakman, a physiologist at the University of Aberdeen in Scotland, in an email. But the second part was more surprising to researchers. The first part of the formula makes sense, since a reduced metabolism means the animals need to obtain fewer calories each day. Now, after 13 years of research, scientists say they’ve discovered the plateau pika’s secret to survival: the animals slow down their metabolism and supplement their usual diet of plants with yak droppings, which contain valuable, undigested nutrients. ( Learn more about another teddy bear-faced pika rediscovered in China.) Unlike some other cold-weather animals, pikas can’t rely on blubber, winter weight-gain, or sleeping through the cold months. Of the 29 species worldwide, the American pika, native to the western United States and Canada, is well known for the way it collects plants in its mouth before stashing the food stockpiles underground to endure the winter.īut how its Asian relative, the plateau pika, survives on dry, wind-whipped steppes, where temperatures routinely dip to minus 20 degrees Fahrenheit (minus 29 degrees Celsius) and plants shrivel in the winter, has long been a mystery. Pikas are pint-size, rodent-like mammals that look like a cross between a guinea pig and a rabbit. But the pikas of the Qinghai-Tibetan Plateau in northwestern China do neither. ![]() To avoid the harsh temperatures and lack of food that come with colder weather, some animals migrate.
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