Wild Yak Moms Take to the Steepest Slopes

It turns out that just after giving birth, wild yak moms take to the steepest hills with their young, according to a new study published in the Journal of Mammalogy.

The study, led by the Wildlife Conservation Society, says that in these societies, the mothers are the real climbers. Unlike male or female solo yaks, mothers will climb around the Tibetan Plateau in China with their calves to heights reaching approximately 16,000 feet (nearly 5,000 meters).

Male yaks, which travel in pairs instead of mom-led groups of 30, stick to the valleys rather than battle the uphill climb.

Researchers aren't sure exactly what drives these yak moms to venture to such steep terrain and high elevation. They suspect this strategy is an adaptive way to avoid predators and to access more nutritious food.

Wild yaks are an endangered species - their precise global population numbers are not known, but scientists estimate the population to be about 15,000 to 20,000, mostly inhabiting the Northern Tibet Grassland, the Wildlife Conservation Society reports. In the last 30 years, wild yaks (Bos mutus) have declined some 30 percent worldwide under the pressure of humans, who herd domesticated livestock into the same territories. Consequently, The Dodo reports, the cold-hearty animals have retreated westward to the parts of the Tibetan Plateau where the habitat has not yet been destroyed or fractured.

But, scientists see this isolated habitat as an opportunity. The remoteness of the wild yak's habitat, the authors say, gives conservationists an opportunity to study a species that has not been largely impacted by humans - unlike bison, their American brethren.

"Here we have a throwback to the Pleistocene," Wildlife Conservation Society biologist Joel Berger, an author of the study, said in a press release. "It is still here, and we by uniting people from different countries have the opportunity to conserve a species, not to mention an ecosystem and a landscape that is larger than all of Montana and Nebraska combined."