Sunday, February 19, 2006
Kiirunan syöntistrategia - Browsing strategy of Rock ptarmigan
Kun tunturissa kaikki varvut ovat lumen peitossa ja puut yltä päältä tykyssä, kiirunoilla on tilanteeseen erikoinen ruokailustrategia. Kiirunat ravistelevat tykkyisten tunturikoivujen alaoksat ensin vapaaksi lumesta ja alkavat syödä sen jälkeen koivuista silmuja. Kiirunat syövät koivuja tunturissa puurajalla, kun taas riekot ruokailevat alempana tunturin rinteen metsävyöhykkeessä. Ilmeisesti kiirunoiden lumesta ravistelemia tunturikoivuja on löytynyt Värriö II:n puurajalta, mutta itse kiirunoita ei ole vielä näkynyt. - Tämä kiirunapari on kuvattu 6.2.2005.
When all the fell herbs are covered by snow and the birches also covered by deposited snow, rock ptarmigans have developed a special browsing strategy. They first shake the trees and free the lower branches from snow. The the birds start to eat the buds. Rock ptarmigans (Lagopus mutus) browse on the tree line whereas willow ptarmigans (Lagopus lagopus) stay lower on the forested slopes. Traces of rock ptarmingan browsing have been found on the peak two of Varrio fells, but the birds themselves we have not seen yet. - These rock ptarmigans have been photographed on 6 February 2005.
When all the fell herbs are covered by snow and the birches also covered by deposited snow, rock ptarmigans have developed a special browsing strategy. They first shake the trees and free the lower branches from snow. The the birds start to eat the buds. Rock ptarmigans (Lagopus mutus) browse on the tree line whereas willow ptarmigans (Lagopus lagopus) stay lower on the forested slopes. Traces of rock ptarmingan browsing have been found on the peak two of Varrio fells, but the birds themselves we have not seen yet. - These rock ptarmigans have been photographed on 6 February 2005.