Tuesday, 30 October 2012

Seabird Summary 2012

Fulmars (pictured left) – have not had a good year. We counted 133 nests, which is a decrease of 35% on last year’s count, well below the 10-year mean of 172 and about half of the 28-year mean. Although we weren’t able to carry out a formal study of fulmar breeding success, we only found 5 fulmar chicks that had reached fledging stage on the whole reserve.

Shags – well here, things looked a bit more rosy with 171 nests counted, an increase of 7% on 2011, and similar to the counts since 2005. However, this is below the 10-year mean of 192 AON, and well below the 28-year mean of 250 AON. Breeding success was down on last year (but last year was an exceptionally good year) but about the same as the 10-year and the 23-year means. Shags this year fledged, on average, 1.25 young per active nest.

Herring Gulls – have done OK this year as well, 266 nests counted which is above the 10-year mean, but below the 28-year mean of 354 AON.

Kittiwake – continue to have a difficult time of it. This year’s count of 4,314 nests is the lowest on record, well below the 10-year mean of 5,653 AON, and less than half the 28-year mean of 10,631 AON. However, to put it in perspective, although the number of kittiwakes has declined by 78% since the highest count in 1989, the counts since 2009 are now in the region of the counts from the 1950s. As far as breeding success goes, not as good as last year (but like the shags, last year was exceptionally good), with only 0.48 young fledged per nest. However, this is about the same as the 10-year mean, and only slightly below the 26-year mean.

Guillemot & Razorbills (latter pictured right) – we do not have the resources to count all the guillemots and razorbills every year, but we do count numbers on the same study plots every year so that we can compare whether numbers. This year guillemot numbers have decreased since last year, and are below both the 10-year and the 28-year means. Razorbill numbers are down on last year too, but are about the same as the 10-year mean, if below the 28-year mean.

Puffins – sadly for many, the puffin breeding numbers went down again this year from 7 birds ashore during the height of the breeding season (so probably with chicks in burrows) last year, to just 4 this year.

Thursday, 11 October 2012

Keeping track...

For the second year in a row, our seabirds were the subjects of closer than usual study this year, with a small number of birds being fitted with electronic tagging devices. This year it was the RSPB undertaking the work as part of their Future of the Atlantic Marine Environment (FAME) Project. This involved attaching small a Global Positioning System (GPS) logger to the feathers of kittiwakes and guillemots, which they carried for just a few days. During that period, the logger recorded an accurate picture of the foraging destinations of the birds thanks to the high precision of GPS technology. These surveys will start to answer one of nature’s mysteries – where do seabirds go to feed when they leave the cliff. This will provide us with important information about what the birds need to thrive and will help us to conserve them in the future. Here's what a couple of our kittiwakes got up to over a couple of days:

The first was tagged on the 26th of May when it was incubating a clutch of two eggs. The map on the right shows the flight path this Kittiwake took during a two day period. The GPS tag attached to the feathers on the birds back logged a GPS point every 1 minute and 40 seconds. In areas where the dots are spread out the bird flew fast and in areas where the dots are clumped the bird slowed down to feed or rest. 

The second Kittiwake was tagged on the 27th of May when it, too, was incubationg a clutch of two eggs.  During the three day period this Kittiwake did three flights out to sea, one short trip south and two longer flights north (see map left). You can see quite clearly where this bird searched for food, flying tight circles. If you look closly you can see the side trip it did to visit the Isle of May.

It is truly amazing to see where these birds go to search for food during the breeding season. The map below shows the flight paths recorded for both of the above Kittiwakes on the same map, and gives a bit more perspective as to how far these small creatures travel over a small period of time. There are still many questions to answer, for instance, these maps show that not all bird go to the same place to feed, so what makes them choose the direction to fly in?  As usual, the more we find out, the more we realise we don't know!

Over the season the FAME Team were kept very busy as they were collecting data on kittiwake, guillemot, razorbill, shag and fulmar flight patterns on Orkney, Fair Isle, Colonsay, Isle of May, the Sillies, North Aberdeenshire, Fowlsheugh Nature Reserve and  Flamborough Head as well as at St Abb’s Head.

Another interesting project that stemmed from this work was "SEA Art in a Differnt Way" a collaboration between artists and scientists, culminating in an exhibition at the Kelvingrove Art Gallery and Museum in Glasgow between the 13th and the 21st October - check out the RSPB blog for more details   http://www.rspb.org.uk/community/getinvolved/b/seabirds/default.aspx