Caribou as Indicator of Climate Change
06.05.2008 - Other
Fewer caribou calves are born and more are dying in West Greenland. A recent study conducted by Eric Post, from Penn State University in collaboration with Mads Forchhammer, from the University of Aarhus in Denmark, shows that the timing of peak food availability no longer corresponds to the caribou's calving period.
The plants on which the caribous feed in springtime (willows, sedges, flowering tundra herbs, etc.) grow with the rising spring temperatures. However, local temperature is speaking far earlier than before, "up to 4 degrees Celsius at the study site in West Greenland over the past few years," said Post.
As the birth season approaches, the caribous migrate towards areas where their food resources are plentiful. But when they arrive at their calving grounds, pregnant females find the plants on which they depend having already reached peak productivity, which means that their nutritional value has started to decline.
While the caribous may be able to respond to this "trophic mismatch" (a phenomenon in which the food availability no longer corresponds to the timing of demand) by having their calving period earlier, scientists are not so confident that the species will be able to adapt fully to the rapid temperature changes yet to come. This study shows the first evidence of a trophic mismatch in a terrestrial mammal as a result of climate warming and suggests the caribou could be used as an indicator species for future climate change.
