Dotterel Charadrius morinellus in north-east Scotland 2023: continued decline, local increase or natural population fluctuations?

A decline of 57% in the breeding population of Dotterel Charadrius morinellus in Scotland was reported between 1987–88 and 2011. Recent surveys of Dotterel on hills in the stronghold in north-east Scotland have recorded variable numbers of breeding Dotterel. In 2023, a coordinated and standardised survey in the eastern Cairngorms was undertaken covering five sites. The survey confirmed that Dotterel are still passing through the eastern Cairngorms and breeding successfully on formerly occupied low as well as high hills. However, Dotterel were absent from some previously occupied sites. The total number of birds recorded in the pre-breeding season and the density of breeding males across the survey area did not suggest a widespread decline in the area. Rather, it indicated that breeding Dotterel numbers were variable across sites with some sites holding high numbers and others none. Where it occurred, breeding was successful with many broods reared to at least near fledging. The possible reasons for these changes in Dotterel numbers and breeding success are discussed. These results have implications for future survey work.