Very Hungry Caribou

Global warming undermines caribou feeding behavior

• Hannah Schardt
• Oct 01, 2008

THANKS TO GLOBAL WARMING, Greenland’s caribou are not only showing up late for dinner—they’re also finding a limited menu once they arrive. American and Danish researchers have found that, in what is known as a trophic mismatch, caribou now arrive at their spring feeding and breeding grounds in West Greenland after their prime food sources have already peaked and begun to lose nutritional value. The animals take their cues from changing daylight hours, relocating in response to longer days. New growth on willows and sedges, however, grows in response to raising temperatures. So a hotter climate—the region has warmed by 7 degrees F in recent years—causes the plants to send out new growth earlier and earlier, before the caribou can get the message. By the time the caribou arrive, ready to eat, breed and birth their young, the plants have already begun to decline.