Thursday, 2 August 2012

So how did the seabirds do this year ?

 Mark Newell, Field Manager for Centre for Ecology and Hydrology, (CEH) writes

"As the Isle of May researcher’s 2012 field season draws to a close now seems a good time to provide a brief summary of how the season fared.  This year was my eighth season working for the CEH  and every year continues to throw up surprises.  The weather this spring and summer has dominated the national news headlines and the blog and it certainly had a considerable impact on our working lives on the isle and for the birds we have been studying.

Living on an island we have to be adaptable but this year has taken things to extremes as the weather has prevented us from getting a lot of things done when we would like.  The conditions have often been far from appropriate for wandering over the wet rocks let alone ringing birds.  So it has been a case of making the most of the good days and knuckling down to the more dull, paperwork tasks on the bad days.  However, at least we can retreat indoors away from the rain but the seabirds have no choice.  Obviously they live in the sea and so are used to water but as explained in previous blog entries ( many puffin burrows have been flooded, shag nests waterlogged and it is impossible for the cliff nesters to sit on eggs or chicks with a waterfall descending upon them.

So how have the seabirds fared in these atrocious conditions?  CEH monitor the return rate of adults to the isle and their diet on an annual basis and these results take a little longer to analyse. There are still some birds within the monitoring plots yet to complete their breeding season but preliminary results suggest a mixed season for the different species.  Razorbills had a fairly average season from the number of young which fledged with guillemots faring slightly better.  Shags also had a slightly above average breeding season despite the somewhat harrowing scenes of chicks that had perished in some of the more extreme wet days.  As mentioned before it was puffins which have suffered the most with a below average breeding season but it was not the catastrophic failure reported in places such as the Farnes and over half the puffin burrows checked managed to fledge young.  It will still be several weeks before we know how well the fulmars have done this year as the chicks won’t fledge for over a month yet and are still balls of grey fluff.  So that leaves the big success story of 2012: kittiwakes.  Despite some nests being blown off the cliffs back in May and chicks and nests washed away in the down pours kittiwakes still had an exceptionally good year.  If the last chicks successfully fledge it could turn out to be one of the best breeding seasons for kittiwakes in two decades."

"All this indicates that there were plenty of fish in the sea, certainly for the surface feeders such as terns and kittiwakes as we saw from the island with huge feeding flocks on numerous occasions. (  Most years it is the abundance and availability of fish which dictates the breeding success or otherwise of the seabirds but the last two seasons have demonstrated that severe weather events can have a huge impact on the birds no matter how resilient they are.  The seabirds could have had a far more successful season on the Isle of May in 2011 had it not been for the major storm that battered the cliffs in early Spring blowing off nests and eggs but barely affecting the puffins.  This year the unprecedented rainfall had less impact on the cliff nesters but badly affected the puffins.  The weather is just one difficulty that our breeding seabirds have to contend with but it remains to be seen if these extreme events become more frequent as the climate changes.  All the more reason to keep returning to the Isle of May to continue the long term monitoring."

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