Svein Haftorn Contribution to the food biology of tits, especially about storing of surplus food. Part IV. A comparative analysis of Parus atricapillus L., P.cristatus L. and P. ater L.

Abstract

Svein Haftorn was born 30 January 1925 in Drammen, South Norway. He became a curator of ornithology at DKNVS, Museet, in Trondheim in 1953, and professor of zoology in 1966. He passed away on 28 July 2003, 78 years old. He was a member of DKNVS and the Norwegian Academy of Science and Letters,and he received His Majesty’s Golden Medal.

As a teenager, Haftorn observed that the forest titmice Willow Tit, Coal Tit and Crested Tit stored seeds during autumn and used them as an additional food supply during winter. His study of the feeding biology and food storing was the subject for his master thesis at the University of Oslo in 1952 and later for his doctoral thesis in 1957. In coniferous forests these birds store seeds and insects at different sites: the smallest one, the Coal Tit, almost entirely in the needled branches, the Willow Tit nearer to the trunk (and partly on the trunk), whilst the Crested Tit store food at intermediate sites. The winter feeding niches coincide with the respective storing sites, thus allowing the species to co-exist within the same geographical area, and to forage together in large mixed flocks during winter. The work has become classical in ecology to explain how closely related species can live in sympatry.