*This paper forms a report to the British Trust for Ornithology.
Change in status of the bridled guillemot after ten years*
Article first published online: 21 AUG 2009
1951 The Zoological Society of London
Proceedings of the Zoological Society of London
Volume 121, Issue 3, pages 657–671, November 1951
How to Cite
SOUTHERN, H. N. (1951), Change in status of the bridled guillemot after ten years. Proceedings of the Zoological Society of London, 121: 657–671. doi: 10.1111/j.1096-3642.1951.tb00762.x
- Issue published online: 30 OCT 2009
- Article first published online: 21 AUG 2009
- Received March 13, 1951
A re-survey of the distribution of the bridled form of the common guillemot, Uria aalge, during 1948-50 has shown that in the ten years since the first survey was made, four colonies have decreased significantly in percentage of bridled birds and one has increased. The total number of colonies for which satisfactory comparisons were obtained was only eighteen. Discrepancies between observers made it necessary to accept only those counts which had been checked by other observers. This result is not statistically significant, but various facts suggest that a decrease in bridled birds is in progress and it is certainly worth continuing the investigation at ten year intervals.