Global Warming: Reindeer Getting Smaller As Arctic Temperatures Rise

Rudolph’s red nose may still be shiny but it will be much smaller than it used to be. Reindeer, who are said to pull the sleigh of Santa Claus as he goes around dropping gifts, are having a tough time as the climate changes and the aspect of global warming affects the polar ice caps.

Contrary to what some would think, warmer temperatures in the Arctic don’t necessarily mean there will be more green patches for the reindeer to feed on. What happens is this: because it is warmer during the winter months, precipitation that would otherwise fall to Earth as snow comes down as rain instead. Coming into contact with the snow already on the ground, the water freezes as well, and forms a hard layer of ice.

Under that hard layer is all the lichen, moss and grass that forms food for reindeer through the long winter months. Usually, they can brush off the soft snow with their noses and get at the food below, but they have no way of breaking the layer of ice that forms during weather events called “rain-on-snow.”

And this has led to a drop in the body mass of the Svalbard reindeer in Norway. Researchers published a paper in the journal Global Change Biology in August wherein they studied 135 individuals every year between 1994 and 2015. And at the annual meeting of the British Ecological Society in Liverpool, England, on Monday, they are going to announce that the Svalbard reindeer, as a species, has likely lost 12 percent of its body mass over the two decades.

According to Science magazine, this loss of body mass has now reached a critical point. Females of the species that weigh less than 50 kilograms give birth to smaller calves or even terminate their own pregnancies when faced with a shortage of food. The smaller calves, after reaching sexual maturity, will produce still smaller calves, making the species lighter and smaller.

However, the researchers also predict that rising temperatures could make the Arctic winter so warm that the ice formed in the “rain-on-snow” events would melt on its own and give the reindeer access to the grass and moss below. If that were to happen, they say the species could, within a handful of generations, go back to being bigger and heavier.

Last month, news emerged from Russia that the same weather event had caused the deaths of some 80,000 reindeer. Those deaths occurred in two episodes, one in 2006 and the other in 2013.