Nest attendance and foraging movements of northern fulmars rearing chicks at Bjornoya Barents Sea

We studied several aspects of the foraging ecology of fulmars rearing young chicks on Bjornoya. To determine precisely the duration of foraging trips during the brooding period, we used an automated logging system that record ed the presence of fulmars fitted with transponders. We also tracked, with satellite transmitters, four parent fulmars during the brooding period, and two after the chick had been left alone. When brooding the chick, fulmars appeared to alternate very rapidly on the nest, with foraging trips lasting on average 8 h. This period appeared constraining for the birds since pare nts lost mass. The growth of chicks was dependent on the ability of the fem ale land not the male) to do short foraging trips. At this time birds are f oraging at an average distance of 60 km from the colony, with birds concent rating on the shelf around Bjornoya. They did not return from one trip to t he next to the same foraging area. As the season progressed and the chicks were left alone on the nest, parents increased the duration and maximum ran ge of foraging trips as well as the distance covered. However, they still p erform a succession of relatively short foraging trips to the east of the B jornoya shelf but they interspersed these short trips with longer foraging trips. One bird returned twice to the same site along the Norwegian coast 5 70 km from Bjornoya, the other foraged at 580 km in the mid-Barents Sea. Av erage flight speed including time spent on the water was 28 km/h and reache d 70 km/h during bouts of more than 1 h when the bird was probably continuo usly in fight.