27 June 2014

Chris Mourant and I crossed over to Lihou at mid-day to complete the Herring and Great Black-backed Gull monitoring for the season. In line with the previous visit on 16 June we worked anti-clockwise around the coast. However, because the first rocky beach contained the most advanced young last time, we did not work this area again. Instead we started at the 2nd beach and then worked around the coast to the gulley at the western end of the island (just north of the Venus Pool).

We had ringed 50 Herring Gull chicks on the previous visit, and we added another 25 on this visit. The 75 ringed this year probably compares with the 100 ringed in 2013 because in that year we were probably able to ring more chicks all at the same time, and therefore covered all the areas more thoroughly. In general 2014 appears to be another season of good productivity for nesting Herring Gulls on Lihou.

Again true to recent form, the Great Black-backed Gulls do not appear to have sustained their breeding numbers from several years back. Only two pairs were located on the ridge of the island (and only two young found on the previous visit), as opposed to the more usual four or five pairs, and they seem more thinly scattered around the coastline nowadays. The reasons for this are not understood. It is highly probably that we will see a fall in the population of this gull on Lihou when we carry out then next national seabird survey – Seabird Count in 2016-2019.

Around ten pairs of Lesser Black-backed Gulls are breeding in the gulley area at the west of the island, and some chicks had hatched recently. Perhaps as many as 15 pairs are nesting on Lissroy, but we will assess productivity for this gull when we undertake our final monitoring visit in early/mid July.

Having completed the work, we walked back across the causeway, pausing for a very useful conversation with Richard Curtis (the Lihou Trust House Warden). Richard’s conclusions were similar to our own regarding the success of the Herring Gulls and the fewer pairs of Great Black-backed Gulls, but the small increase in Lesser Black-backed Gulls. He also thought the newly erected signs and ropes were helpful for the many visitors to the island. It was interesting to note however, that after a good period without evidence of rats, they are becoming more noticeable again by the house, even being seen in daylight.



29 June 2014