Ibis

Winter Sports Threaten Indigenous Mountain Birds

In the winter months the mountain ranges of central Europe attract thousands of tourists for skiing, snowboarding and other outdoor sports, but conservationists fear this annual invasion may threaten indigenous bird species, including the Capercaillie. The research, published in the journal IBIS, reveals how the growth of human recreation may be a key factor in the rapidly declining population of these iconic alpine birds.

The Capercaillie (Tetrao urogallus), also known as the Wood Grouse, is the largest member of the grouse family and is renowned for its mating display. It is most commonly found in the alpine regions of Germany and Switzerland where its population has suffered a severe decline.

Dr Thiel’s team monitored the populations of alpine Capercaillie in Germany and Switzerland close to recreation sites during two winter seasons. After analyzing 1130 samples of Capercaillie droppings the team found a marked increase in stress hormone levels closer to locations with winter recreation activity.

Capercaillie are expected to be particularly sensitive to winter tourism because during the winter months it is restricted to feeding on conifer needles which have a low nutrient content and are difficult to digest. This requires a long digestion time and results in a low rate of energy intake. Therefore any sudden energy expenditure, such as escaping from humans who will be perceived as predators, is costly.

“We believe that Capercaillie are especially sensitive to winter recreation, and the risk for negative affects is high," concluded Thiel. "The access of people to undisturbed Capercaillie winter habitats should therefore be prevented. Recreation activities should be kept away from core Capercaillie wintering areas, especially during the physiologically most demanding winter days."