Wednesday, 19 October 2011

Seabird Summary 2011

I am pleased to say that 2011 was a good year for the seabirds - its been a while since we've been able to say that. We must be careful not too read too much into this though, population numbers fluctuate wildly from year to year because there are so many factors effecting the seabirds, but nevertheless, it is nice to be able to report good news for once after all the years of doom and gloom.

You may remember me reporting that the breeding season caught us on the hop somewhat this year, with the birds starting to lay eggs more than a week earlier than ever recorded before. So we had to start early with our monitoring too.

The first monitoring to start is the shag productivity monitoring which the Seasonal Ranger carries out, starting in April and carrying on through until all the shag chicks have fledged, which can be as late as September some years. Basically this involves following the breeding activity at nests on a series of fixed study plots throughout the whole season, recording the number of nests built, the number of eggs laid, chicks hatched and eventually the number of young fledged per nest. This means you can then calculate the breeding success which was 1.85 chicks per active nest for shags this year, the second highest on record! Picture top left - a shag, looking resplendent with its shag (from which it gets its name) all fluffed up.

Next off is the whole colony count of herring gulls and shags, and yes, this is what it seems - we count every single nest we can find of each species. This is quite time consuming as it involves walking all of the cliff tops, scanning the cliffs from every possible angle and vantage point in order not to miss any nests. The count has to be done over several days as it is pretty physically tiring going up and down all the cliff tops, and out onto all the headlands, but also mentally - it takes an awful lot of concentration! Then we go out on a boat (weather permitting) and count the areas that cannot be seen from land. Both shag and herring gull numbers were very similar to the last few years (with 220 pairs of herring gulls and 160 pairs of shag . Picture right, a herring gull chick and an egg - it is best to count them at about this stage, any later and all the chicks start to run all over the place and its difficult to work out the number of active nests!

Then I start the kittiwake productivity monitoring - which follows the same principles as the shag productivity. Again, the kittiwakes had a good breeding season this year, with 0.95 chicks being fledged per active nest. This may not sound very high, but it is significantly above the 25 year average of 0.63.

Next up I start on the auk monitoring - now as we have something like 33,000 guilliemots it would be madness to try and do whole colony counts of these each year, so we only do total counts every five years. But each year we count the number of guillemots and razorbills on a series of fixed plots, doing a series of counts in the first three weeks of June and then taking an average. This gives an indication as to whether numbers are increasing or decreasing from year to year, this year counts of these two species were up on last year. Picture bottom left, a razorbill chick, oft overlooked.

Then comes the whole colony counts for fulmar and kittiwake - again, following the same principles as the counts for gulls and shags...but much more mind boggling as there are so many kittiwake nests! Again counts have stayed about the same as the last few years with 4,688 pairs of kittiwake and 205 pairs of fulmar.

Then last, and very much least, is the puffin count. This involves counting the number of birds seen ashore on one evening in late June. This count doesn't take long as there are so few puffins at St Abbs, this year there were just 7 birds ashore.

So, all in all, the seabird monitoring is a pretty major undertaking and keeps us pretty busy. All the data we gather doesn't end up on a shelf in the Rangers' Office, but gets fed into a national database and so helps to add to the picture of how seabirds are faring in the UK as a whole. And as the UK is the breeding site of nearly half of Europe's breeding seabird population it is pretty important that we know what is going on, and if possible, to work out why, and is there anything we can do about it. Also, seabirds are excellent indicators of the health of the marine environment as a whole, so another good reason to justify all our hard work!

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