Arrival and pre-nesting period of the snow bunting Plectrophenax nivalis in East Greenland

Abstract

The first snow bunting males arrive in Northeast Greenland in early April, 6-8 weeks before nesting and 2 4 weeks ahead of the females. At this time temperatures regularly reach -25 to -30°C and snow storms may rage for days. The living conditions during this long-lasting pre-nesting period and its possible function are described and discussed. Based on 781 birds caught. .ringed, and measured, and on observations on phenology, diurnal rhythm, night roosts, etc., it is shown that the age ratio in males is close to 50/50 first living year/adults, that adult males arrive and occupy territories earlier than first year males, that first-year males have shorter wings and are leaner than adult males, that the birds lose weight during spells of inclement weather early in the season, that diurnal rhythm is apparently governed by direct insolation, that males apparently greatly outnumber females in the populations, and that competition for the optimal territories is probably the selective force behind the prolonged pre-nesting period in males.