Reindeer on a group of Norwegian islands are shrinking, as climate change cuts off their food supply, scientists have warned.
Rising temperatures in the Arctic have led to increased rainfall, which freezes when it hits the snow, concealing lichen, a valuable food source.
Since 2000, the weight of an adult reindeer in Svalbard has fallen by 12 per cent, according to a study presented at the British Ecological Society (BES).
“Twelve percent may not sound very much, but given how important body weight is to reproduction and survival, it’s potentially huge,” study leader Steve Albon of the James Hutton Institute in Scotland, told AFP.
Previous research shows that when the average weight for an adult reindeer falls below 50kg, the population declines.
The average adult weight of a reindeer born in 2010 is just 48 kg, 7 kg less than those born in 1994.
While reindeer numbers have increased over the past two decades, meaning competition for food is greater, their smaller size puts them at risk of “catastrophic die-offs” because of increased ice on the ground.
Lichen is the staple of a reindeer’s diet during the winter months, but it’s rapidly becoming more inaccessible as ice covers over it.
As a result, the BES said: “The reindeer starve, aborting their calves or giving birth to much lighter young.”
In the past decade, at least 80,000 reindeer have starved to death in Siberia, as thick layers of ice concealed lichen.
In November 2013 alone, 61,000 reindeer, nearly a quarter of the local population starved to death as a result of climate change-related freezes.