Our favourite festive animals are shrinking due to the effects of climate change. Warmer winters causing fewer food supplies are among the factors at play.
Ecologists have found that reindeer are shrinking due to the impact of climate change on their food supplies.
Over the past 20 years, reindeer on the Svalbard archipelago in the Arctic have got smaller and lighter.
According to the British Ecological Society, which released the findings, the past two decades have coincided with a period of noticeable summer and winter warming in the Arctic.
Each winter, ecologists from the James Hutton Institute, the Norwegian Institute for Nature Research and the Norwegian University of Life Sciences measure and weigh the Svalbard reindeer. They catch, mark and measure 10-month-old calves, then return every year to track their size and weight as adults.
Their latest survey showed that over 17 consecutive cohorts, the adult reindeers’ weight declined by 12 per cent, or from 55 kg for those born in 1994 to just over 48 kg for those born in 2010.
Study leader, Professor Steve Albon, commented in a statement that three factors – all influenced by climate change – are responsible for the shrinking reindeer.
He explained that snow covers the ground in Svalbard for eight months of the year, usually limiting grass growth to June and July. However, as summer temperatures have increased by 1.5 degrees Celsius, pastures have become more productive. This allows female reindeer to gain more weight by the autumn and therefore conceive more calves.
Warmer winters also mean more rain, however, he added. The rain falls on snow, where it freezes and prevents the reindeer from accessing the food beneath the snow. As a result, the reindeer starve. They may then abort their calves or give birth to lighter young.
The third factor is that over the past two decades, reindeer numbers have doubled, resulting in greater competition for food in winter.
Albon warned: “The implications are that there may well be further smaller reindeer in the Arctic in the coming decades but possibly at risk of extensive die-offs because of increased ice on the ground.”
Image credit: foilistpeter/ CC BY-NC 2.0