Climate change is so powerfully affecting reindeer habitat that the animals are shrinking from hunger, scientists have discovered.
Over the past 20 years, reindeer in the Norwegian archipelago of Svalbard, north of the Arctic Circle, have grown smaller and lighter, researchers found. The reindeers’ average weight dropped by 12 percent — from 121 pounds for animals born in 1994 to just 106 pounds for those born in 2010, according to a study.
That change may not seem like very much, “but given how important body weight is to reproduction and survival, it’s potentially huge,” lead researcher Steve Albon of Scotland’s James Hutton Institute told AFP news agency.
Albon quipped to The Telegraph in London that Santa Claus might need twice as many reindeer now to pull his sleigh, but climate changes are presenting a dire situation for the animals, he warned. He attributes the animals’ decline to the effects of warming on their food supply. It’s not only rapidly shrinking animals he worries about but also the potential for a mass die-off.
“The implications are that there may well be more smaller reindeer in the Arctic in the coming decades, but possibly at risk of catastrophic die-offs because of increased ice on the ground,” said Albon, who presented the research findings Monday at the annual meeting of the British Ecological Society in Liverpool.
With warmer summers, more grass and lichen are growing in Svalbard, which is good for the animals because females then gain more weight and conceive more calves, according to Albon. But as the warmth stretches into the winter, rainfall begins to freeze in solid, impenetrable sheets on the ground, blocking access to the lichen and moss below, he says. Reindeer can reach food through snow, but it’s nearly impossible to reach it through ice.
The ice problem was linked to the deaths of 61,000 reindeer in 2013 and 20,000 in 2006 in Siberia.
As pregnant females lose weight in Svalbard because of the ice, they give birth to smaller, weaker calves or abort.
A complicating factor is that more food in the summer sustains larger numbers of animals, so then there is more competition for the dwindling winter stores, the researchers found. The herd that has been the focus of the study has increased to about 1,400 animals from 800 since the 1990s, though the animals are punier.
Arctic temperatures are rising faster than the world average amid increasing greenhouse gases in the atmosphere.
The Svalbard project scientists amassed the data by catching, marking and measuring reindeer each year since 1994 to track their size and weight.