Reindeer survive typically harsh Arctic winters by using their specially adapted hooves to scrape through the snow to nibble on the lichen and moss below. But paradoxically a warming climate is making it harder for them to reach this food, and research shows it has led to a drop in reindeer birthrates.
When rain falls on snow, the snow melts and refreezes, creating layers of ice that make it more difficult for reindeer to scrape through to the fodder below. Climate records going back to 1960 show that warmer winters have resulted in more rain-on-snow events in Arctic regions. By comparing the weather data with reindeer herd birth statistics from Norway and Finland, researchers have shown that birth rates tend to drop in summers that follow winters with lots of rain-on-snow events.
The findings, which were presented at the American Geophysical Union’s annual conference in New Orleans in December, found that rain-on-snow events have started earlier and become more common and widespread in interior regions in recent decades. Areas with dense reindeer herds have been hardest hit because of greater competition for scarce resources. The findings may help to inform how land is used to allow reindeer herders winter access to regions less affected by rain-on-snow events.
