Burhou, Alderney 

09/10 July

One of the most important seabird trips of the season for me is always the last one, as this focuses on ringing Lesser Black-backed Gull chicks on Burhou, Alderney – the largest colony of this species (by far) in the Channel Islands at c 1,000 pairs. In 2009 a visit on 09/10 July proved ideal, for although 25% of the chicks were too small to take colour rings, the remainder were of sufficient size (216) and no birds were large enough to fly/flap off. I therefore aimed at the same weekend this year – 09/10 July.

 Overall this proved to be a good decision – as we had very good, calm weather with slight seas – enabling good access and egress from Burhou, and the chicks were at pretty much the same stage as in 2009 – enabling a very good number to be ringed. If anything, the 2010 gull breeding season looks to have been more productive than in 2009. The Alderney Wildlife Trust nest count for 2010 is just over 1,000 pairs, compared to c 750 last year.

 The three person team this year comprised Jen Stockdale (the Alderney Wildlife Trust’s ecologist), Chris Mourant and me. Chris and I flew up from Guernsey on Thursday evening, arriving in Alderney within ten minutes of Jen, who had been in the UK for most of the previous week.  The AWT kindly put Chris and me up in the Essex Farm Hostel, and after a fish and chip supper we spent half an hour looking over Longis Bay – where an adult and juvenile Mediterranean Gull flew in across the coast.

 By 0800 the following morning we were onboard Sunrise, with Roland Gauvain once again taking us across the Swinge to Burhou. It was wonderful to be back on the island. It took half an hour to get all the gear prepared, but then we began to work the Lesser Black-backed Gull colonies looking for chicks. We worked really hard over a very full day to work the hut area (very thin this year), and then the main colony (mush more impressive), which sweeps from the southern side of the hut all the way out to the western end of the island.

 Most chicks were just about large enough to take a colour ring, although a minority had to be fitted only with a metal ring. We only stopped for a short tea break and for lunch – both times of course having to boil fresh water for the flask to enable me to fit the small colour rings without snapping them.

 At mid-day we crossed over to Little Burhou, where gull numbers and productivity appeared to be low this year (certainly by comparison with 2009). Only a handful of gull chicks were ringed on this islet. Apart from a couple of fledged juvenile Great Black-backed Gulls no other chicks of this species were seen. All the European Shags had, as expected, fledged by this visit, and only a couple of very advanced (but not quite fledged) Great Cormorants were left in one nest.

 259 Lesser Black-backed Gull chicks were ringed on this first day – all but 64 also with colour rings! By early evening we were all exhausted, but very content with our day’s work.

 It was, once again, a very real privilege to stay on the island overnight and to listen to the gulls in the colonies. One of my favourite vistas in the Channel Islands is that from the doorway to the hut on Burhou– looking out over the edge of the Lesser Black-backed Gull colony and across the fast-flowing Swinge to Les Etacs with its myriad of Northern Gannets wheeling overhead.

 The following day we were up early to complete the search for gull chicks to the north-east of the hut – where only a few were located. We then completed working the far end of the main Lesser Black-backed Gull colony, that we had not quite reached the previous evening. This proved very worthwhile with another 75 LBBG chicks being ringed on this day (64 with colour rings).

 This resulted in a total of 334 Lesser Black-backed Gull chicks being ringed – 259 with colour rings – both new records for Burhou!

 In addition 18 Herring Gull chicks were ringed – one of which may have been a hybrid Herring/Lesser Black-backed Gull (16 with colour rings).

 With a little time left we managed to complete another full island gull count (the third of the 2010 season), and also read 20 colour rings on adult Lesser Black-backed Gulls. 12 were adults that had been ringed on the nest on Burhou in June 2009 (and one of these was a new sighting of a bird that had been seen in Portugal and Spain over the previous autumn/winter), and seven were adults ringed on the nest on Burhou in June 2010. The remaining bird was ringed as an adult in the winter of 2004 at Stoke Orchard landfill, Gloucester. It had only one previous summer sighting in mid July in Somerset, England. This is the third adult Lesser Black-backed Gull, which appears to be breeding on Burhou, which has been ringed in the winter period north at the Gloucester landfills.

 At 1 p.m. on Saturday 10th July, Roland returned as arranged and we left Burhou. Coming away from the island I had a wonderful sense of achievement in that the seabird monitoring and ringing was now complete for the 2010 season – and it had been very successful.

 Entering the Alderney’s harbour we saw another adult Mediterranean Gull fly over. Back at the hostel, Chris and I tidied up and then Jen kindly ran us back to the airport to catch our flight back home to Guernsey.

 

PKV

14 July 2010