Reindeer (Rangifer tarandus), known as caribou in Canada and Alaska, aren’t the only ones that are at risk from the die-offs. Nomadic herders in the Yamal-Nenets Autonomous Okrug of West Siberia, are also threatened.
The Yamal-Nenets administrative region is the most productive reindeer herding region in the world. Because of huge reindeer losses in 2006 and 2013 due to extreme weather events, Scientists from the Arctic Centre at the University of Lapland conducted a study of the possible linkage between sea ice retreat/thinning and rain-on-snow events (ROS) on the region’s social–ecological systems, reports Phys.Org.
The research team interviewed nomadic herders to find out how global warming and a changing climate is affecting their unique way of life. One of the first things they learned is that while rain-on-snow does not cause problems in the spring, ROS can be catastrophic in the fall of the year.
Rain turns into a crust of ice, several centimeters thick as the freezing temperatures return in the fall. This crust prevents the reindeer from eating fodder beneath the snow during the winter months. This very thing occurred in 2006 and 2013, and now, for the first time, researchers have been able to link the two extreme weather events with sea ice loss in the adjoining Barents and Kara seas.
Research professor and lead author of the study, Bruce Forbes says, “The private herders who lost all their animals were hardest hit because, for them, it is really a subsistence economy. The private herders have had to become full-time subsistence fishermen to support their families while they rebuild their herds with breeding stock borrowed from their neighbors and relatives.”
Famine hit the reindeer herds in 2006, killing 20,000 animals. Again, in 2013, at least 61,000 reindeer died, representing almost one-quarter of the 275,000 reindeer on the Yamal Peninsula. The reason the 2013 event was so disastrous was because heavy rains saturated the snow cover clear down to the bottom. Temperatures plummeted and reindeer across the whole region were unable to break through the thick layer of ice.
Forbes says that normally, autumn snowfall covers the vegetation that reindeer feed on. Occasional rains can lead to patches of crusted snow or even ice patches, but the reindeer can still either eat around them or push through them.
“Normally stronger bulls would work to break through the ice crust so that females — many of them pregnant — and yearling calves can access the fodder beneath,” says Forbes. “The best condition is powder dry snow, which is easy to dig through to the ground layer of lichens and other vegetation beneath.”
With climate change continuing to have an effect on global weather patterns, it will also create continuing catastrophic die-offs of reindeer and other creatures as their natural habitats are turned upside-down by extreme weather events.
Researchers used interviews, data from satellite sensors, climate modeling that focused on 2006 and 2013, as well as long-term sea ice and atmospheric conditions relating to the time periods. This very interesting study was published in the journal Biology Letters on November 16, 2016.
