Breeding Ecology of Forest Dwelling Grey Buntings Emberiza variabilis: Territorial Fidelity and Intense Home Range Overlap

Abstract

Abstract. The breeding ecology of forest-dwelling Grey Buntings Emberiza variabilis, particularly territorial fidelity and home range overlap, was studied in a beech forest from 1996 to 1999. Adult males arrived in the study area significantly earlier than young males; females arrived six to ten days later than males. During the 1999 breeding season, 10 of 12 males established territories, mated and bred in the study area. Conflicts between the males were frequent from early May to May 15, but decreased drastically thereafter. Although song areas of some males overlapped before May 16, they separated clearly on and after that day. Six of the 10 established males established territories on the same site where they had bred the previous or earlier years. Thus, males that bred in the study area returned to the same territories. Their home ranges overlapped extensively, even after their song areas were separated. Twenty-three nests were found during the 1999 breeding season. The male parent was identified in 17 of these nests, and they were the ten established males. In those nests, the female parent also was identified. The result was that the same pairs repeated breeding after failure. Six other nests were renesting of these pairs or the nests of other pairs at the edge of the study area. The mating system of the Grey Bunting is suggested to be social monogamy.