This iconic festive species has become smaller and lighter over the last 20 years, according to a study on reindeer in Svalbard, Norway.
The scientists have found that the adult reindeers’ weight has declined by 12% over 16 years, from 55kg for those born in 1994 to just over 48kg for those born in 2010.
“The implications are that there may well be more smaller reindeer in the Arctic in the coming decades,” says Professor Steve Albon who led the study. “But [they are] possibly at risk of catastrophic die-offs because of increased ice on the ground.”
Albon believes that three factors are responsible for the change in reindeer weight.
Although increased summer temperatures have meant that there is more food, allowing female reindeer to gain more weight and conceive more calves, there are also warmer winter temperatures.
These higher temperatures in winter, there is more rainfall than snowfall, which freezes over the snow and prevents the reindeer from reaching their food. The reindeer starve and either abort their calves or give birth to much lighter young.
Over the past 20 years, reindeer numbers have doubled leading to greater competition for food in winter.