European bison help song birds during breeding season
Research shows that passerine birds favour hair from the European bison’s winter coat for making their nests. These are the first results from a larger study on the breeding success of song birds in the dunes being carried out in collaboration with the Van Lennep bird ringing station. When there is a lack of bison hair, the birds use moss. PWN uses all research results to make the most appropriate management decisions.
Composition of nesting material
In the European bison’s habitat, the Kraansvlak in the South Kennermerland National Park, the nests consisted of just 74% plant materials, such as moss and twigs. In the Kennemer dunes, where there are no bison, the nests consisted of at least 97% plant materials, a huge difference. The preference for bison hair makes sense: the hair is woolly and soft compared to the hair of other large herbivores like the Scottish Highlander or Konik horse. Bison hair provides good insulation and a good breeding temperature for the eggs.
When the temperature rises in early spring, the bison lose their winter coats, scratching them off on trees and shrubs, leaving loose hairs behind. The passerine birds, such as the European blue tit or great tit, are busy building nests during this period and make good use of the thick winter coats.
Applied biology students at the Aeres University of Applied Science in Almere will further analyse and study the nest in order to see whether the nesting material has an effect on the breeding success of the passerines. “We are very interested in these results. We suspect that the nesting materials definitely have an influence, but that the weather conditions in spring have the greatest impact on the breeding success of song birds,” according to Esther Rodriguez, PWN biologist.