Site use and fidelity in the common guillemot Uria aalge.

• Published in: Ibis
• Main Authors: Harris, M.P., Wanless, S., Barton, T.R.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 1996
• Subjects: Zoology; common guillemot; Uria aalge; uria
• Online Access: http://nora.nerc.ac.uk/id/eprint/12680/; http://onlinelibrary.wiley.com/doi/10.1111/j.1474-919X.1996.tb08057.x/abstract

The site fidelity of 470 colour-ringed Common Guillemots Uria aalge with at least 1 year of breeding experience was followed on the Isle of May from 1982 to 1993. On average, 85.7% of birds recorded breeding at a site in any year were present at the same site in the following season. Of those which did not retain their site, 35% had moved to another site, 25% were nonbreeders and 40% were not seen. Site- fidelity of birds which returned to the colony the next year was 91%. There were no significant age or sex effects, but there were significant (and unexplained) year and area effects. Most birds which changed sites moved less than 2 m. Some birds which obtained a new site improved their nesting success, but many others became nonbreeders; it is speculated that the former chose to move site, whilst the latter had been evicted.