Seasonal variation of birds on a feeding site in a suburban area near Oslo, Norway

The birds visiting a feeding site near a villa in a suburban, residential area in Bærum municipality, west of Oslo, were monitored daily during 1997 - 99, and at irregular intervals during 1993 - 96. Sixteen species had a frequency of more than one week during 1997 - 99. The most common species were: Magpie, Great Tit, Blue Tit, Greenfinch, and Tree Sparrow, all of which occurred during most of the year. There was a clear seasonal pattern in the occurrence of most species. Three species, Siskin, Redpoll, and Brambling, were irregular and occasionally present in relatively large numbers. Invasions occurred especially during cold spells. Among migrant birds, the Blackbird was regularly present during winter. The Robin overwintered irregularly, especially in mild winters.