Estimation of home range for varied tits (Parus varius) in late autumn near the northern range boundary of siebold's beech (fagus crenata) in the scope of estimating dispersal distance of beech seeds

Abstract

As a part of a study estimating the maximum dispersal distance of beech seeds by various bird species near the northern range boundary of beech (Fagus crenata), a varied tit (Parus varius) was captured and a small radio transmitter was attached to the bird in late autumn at a beech forest in Kuromatsunai, Hokkaido. The bird was then tracked for five days by the radio-telemetry method. By using triangulation with two azimuths and the MCP (minimum convex polygon) method, the home range of the varied tit was estimated to be between 2.1 ha and 6.5 ha per day and 11.4 ha in total. The maximum seed dispersal distance by the bird was estimated as 163 m and 529 m. Although the study period was more than a month longer, estimated home ranges for other Paridae overseas showed similar values (14.7 ha for Poecile hudsonica and 12.6 ha for Parus montanus), suggesting that the method applied in this study was reasonably valid. Near the northern range boundary of beech, isolated beech communities are separated from each other by distances between ca. 2 and 4 km. Thus, it is hard to consider that these communities were initially established from beech seeds dispersed by varied tits.