Movements of Crows in Urban Areas, Based on PHS Tracking

抄録

　Few ecological surveys of jungle crows (Corvus macrorhynchos) have been done in urban areas because it is difficult to track them, but we have succeeded in tracking the crows using a recently developed technique, attaching a PHS (Personal Handyphone System) location device, in Tokyo and the surrounding area. We classified their daily home ranges into roosts, morning habitations, and diurnal habitations. We analyzed their daily movement patterns, and classified them into sedentary and two migrant types. Their flight distances were longer in the non-breeding season than in the breeding season. The crows were assumed to disperse to new areas in the non-breeding season. Though PHS tracking has several problems such as short battery life, it is a useful technique for obtaining detailed data on large birds’ movements in urban areas.