St Margarets Island and Caldey Island

 

We have obviously finished the counts of the seabirds on the cliffs and islands while the seabirds were sitting on eggs but we are miles off collating the seabird counts from the sea and the cliff photographs!  We will let you know when we have adding everything up.

The seabird breeding season is clearly late on Caldey and St Margarets island this year. 

Its the most synchronous season in years, probably to do with the cold wet weather in March which stopped everything doing anything for a time. Its very different to most years in the last decade.

 On Thursday last week we ringed 99 Cormorant chicks in the largest sub-colony of Cormorants on the south coast of  St Margarets island.

 Most of the chicks were about half grown and so are two to three weeks behind recent years. 

There were a few large chicks which were not approachable and a few nests with tiny newly hatched chicks, no clutches of eggs.

  The great black-backed gulls (GBB) seem to have also had a good year, although the dry trampled vegetation towards the edges of the island helped to find the big chicks.

 

We ringed 26. We found very few in the thicker sea beet inland maybe the clouds of pale yellow pollen obscured our vision!!

We found a decapitated grey squirrel in one of the GBB nests - perhaps a road casualty scavenged by the GBB's. 

On another note the Kittiwakes all seemed to be incubating whereas by now they would traditionally have small chicks so maybe also affected by the poor March weather.

It sounds like some Kittiwakes on Skomer may have chosen not to breed this year so we need to get another look at the St Margaret’s Island birds in the next couple of weeks.

 

Today we visited Caldey again to ring a sample of Herring Gull chicks  and between two of the sub colonies managed to find 156 well grown chicks, a few almost ready to fledge but most about half grown.  More surprising was the number of dead chicks especially around Sandtop where at least 100 were found and at both sites we recorded no regurgitates so our conjecture is that they are starving.  In most years we have seen a lot of worms regurgitated and we wonder if the dry conditions of recent weeks have meant the adults are finding it difficult to forage.

The Caldey Herring Gull colony count this year was 1,620 pairs which was down slightly on 2022 and compares miserably with 1976 when over 3,700 were breeding there.  All the other seabird numbers were very similar to 2022.  Steve recalls over 400 pairs of guls nesting between Tenby and Saundersfoot with over 100 on St Catherines Island, today there are less than 20 and just 3 pairs respectively although there may be a few more on the rooftops of Tenby now.

 

Anna & Steve Sutcliffe  and the Pembrokeshire Ringing Group