Breeding Success of British Kittiwakes Rissa tridactyla in 1986-88: Evidence for Changing Conditions in the Northern North Sea

• Main Authors: Harris, M. P., Wanless, S.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 1990
• Subjects: Zoology; rissa tridactyla
• Online Access: http://nora.nerc.ac.uk/id/eprint/4525/; http://www.jstor.org/stable/2403576

(1) Data on breeding success from thirty-five British and one Irish kittiwake Rissa tridactyla colony were collected between 1986 and 1988. (2) At each colony the mean number of young fledged per completed nest was similar in 1986 and 1987, but at North Sea colonies success was significantly poorer in 1988. (3) Colonies in the northern North Sea showed a negative relationship between breeding success and latitude in 1986 and 1987, whilst in 1988 there was a significant north-south trend in success over the whole length of eastern Britain with colonies in the south being more successful than those in the north. There was no similar pattern amongst west coast colonies. (4) In North Sea colonies most breeding failures occurred at the chick stage, but on the west coast some birds did not lay whilst others failed during incubation or soon after hatching. (5) Amongst North Sea colonies it seemed likely that food shortage during chick rearing was responsible for the low breeding success. This conclusion was consistent with the independent finding that a series of poor recruiting year classes had caused a decline recently in the Shetland stock of sandeels Ammodytes spp.