Thursday, January 28, 2010

27th January,2010.

Our Greater Scaup flock in Inner Loch Indaal appears to have taken a further reduction in numbers over this winter. The birds can usually be seen at the head of the loch in one or more large groups and afford good views. Compared to the maximum last winter (08/09 ) we now seem only to have around 50% of previously ,i.e. just under 500. It's possible that another large grouping is elsewhere, but searches have produced nothing.

My interest stemmed from consideration of the potential effects of the various works going on within and around Inner Loch Indaal , i.e. dredging and sewage disposal improvements. I managed to find the copy of a paper I'd photocopied previous to coming here in 1999 ( it just shows you should never throw anything away! ), which made interesting reading. It was written by D.G.Salmon and dealt with the numbers and distribution of Scaup in Britain and Ireland. As a species it favours shallow, sheltered bays and feeds on ragworms, round worms and blue mussels. On Islay it had been shown previously to have been attracted by spent barley disposed of from one of the distilleries. A study by Len Campbell on the reduction in numbers in the Firth of Forth linked this with the introduction of improved sewage treatment processes and one can perhaps see a parallel with the situation here, not just for Scaup but Goldeneye too.

Of particular interest were the figures quoted for Scaup on Islay during the period 1965-66 to 1980-81.

The maxima for the period 65/66 to 60/70 was 680, that for 70-71 to 74/75 was 1500, for 75/76 to 79/80 1300 and for 80/81 to 84-85 1200. I suppose the counts from, say, the last three years or so showing around 900 birds present are slightly reassuring given the fluctuations apparent within the above figures. However,this winter's figures might give cause for concern and suggest a closer look is taken both at the numbers and the distribution of birds in the future. Sadly with the remorseless march of progress and the incremental raising of environmental standards there is probably little we can do to influence matters!!

No comments: