To ask the Scottish Executive what the estimated breeding population is of (a) red-breasted mergansers and (b) goosanders and what information it can provide on how the numbers and distribution of these birds have changed in the last 10 years.
The Scottish Executive does nothold this information centrally but is aware of the following;
Red-Breasted Mergansers
The most recent estimate of numbersof breeding red-breasted mergansers are:
561 males (299 to 915, 95% ConfidenceLimits)
591 redheads (females and immatures)(262-1,019, 95% Confidence Limits).
These estimates are based oncounts made in 1987 and 1997 prior to the main breeding period, and are regardedas minimum estimates.
Data from the Wetland Bird Surveyindicate that mergansers are widespread throughout Scotland, andthat there has been virtually no change overall in the size of the population atkey census sites over the last ten years.
Goosanders
The most recent estimate of numbersof breeding goosanders are:
1,422 males (988 to 1,882, 95%Confidence Limits)
2,041 redheads (females and immatures)(1,537-2,589, 95% Confidence Limits).
These estimates are based oncounts made in 1987 and 1997. These counts were made during the main breeding periodfor goosanders.
Data from the Wetland Bird Surveyindicate that goosanders are widespread throughout Scotland. Theremay have been a slight increase in the size of the breeding population, but a slightdecrease in the size of the over-wintering population.