Scientists worry that Madagascar’s greater bamboo lemurs may be slowly starving to extinction due to climate change.

Normally, these rare primates rely almost entirely on the tender shoots of a single species of woody bamboo, but with specialized teeth, they are also the only mammal capable of eating the culm, or the less-nutritious woody trunk of bamboo trees, which they can survive on for part of the year.

According to recent findings, which were just published in the journal Current Biology, these lemurs spend 95 percent of their feeding time eating woody bamboo; they only eat the culm during the dry season from August to November, when the tender shoots are unavailable.

Unfortunately, dry conditions are forcing them to rely on less nutritious food for longer, which is anticipated to have a serious impact on their ability to survive.

“This is why, for extreme feeding specialists like the greater bamboo lemur, climate change can be a stealthy killer,” said co-author Patricia Chappell Wright, a primatologist at Stony Brook University.  “Making the lemurs rely on a suboptimal part of their food for just a bit longer may be enough to tip the balance from existence to extinction.”

According to the researchers, rainfalls in Madagascar are changing annually, and the dry season on the island is expected to lengthen. With those tender shoots arriving later and later, there’s nothing available for mothers, or their babies when they arrive in November.

“With an increasingly prolonged dry season, greater bamboo lemurs have to rely upon this challenging food source for longer,” said Stacey Tecot, an assistant professor in the UA School of Anthropology. “Prolonged dry seasons can also interfere with the reproduction of species like the greater bamboo lemur that rely on annual changes in day length to reproduce, once per year. Day length is a great cue if it aligns with seasonal changes in the food supply, so mothers have sufficient nutrients for conceiving, gestating and nursing their growing offspring. But, if the dry season is prolonged, reproduction won’t be well aligned with these important nutrients.”

The impact of climate change is now adding to the threats they already face, ranging from habitat loss to poaching, which has left just an estimated 600 left in the wild. They are now listed as Critically Endangered on the IUCN Red List of Threatened Species.

While the future looks grim, researchers are hoping to use their findings to better understand how to protect lemurs, and other species who are being similarly impacted by climate change, before they reach the point of no return.

In an effort to help them rebound, conservationists are starting projects to plant more bamboo and create corridors in important areas for them that can be irrigated when the dry season persists. Conservationists are also encouraging the growth of other economically valuable crops, including vanilla and coffee, that can be grown in their shade to protect more forests from being cleared for other agricultural purposes.

Photo credit: Thinkstock