Lihou 

29 June

Given other work and seabird commitments, and the dates that the Lihou causeway was open towards the end of June, we always knew that a visit on 29 June was likely to be a little too late for ringing the maximum number of Herring Gull chicks. This was even truer given the slightly earlier than average breeding season for many gulls in 2010. Nevertheless Jamie Hooper and Paul Veron went across to the island as soon as the causeway opened at 2 p.m.

 The weather was near perfect with virtually no wind and some welcome cloud cover. It was quite sultry, but not as hot as it would have been in a clear blue sky with unbroken sunshine.

 Like our previous visit on 11 June we made an anti-clockwise circuit of the coast. It was soon obvious that many of the Herring Gulls were large, with some already on the wing. With the tide dropping fast many gulls would have been on the acres of exposed shore, being impossible to locate on our visit.

 Given this somewhat late visit it was even harder than usual to assess breeding productivity, as many of the gulls were already far from the nests. All the usual sub-colonies appeared to have some young, so the gulls had clearly enjoyed reasonable success around the island. It was a better picture than in 2009, when the long-staying Snowy Owl had fed on gull chicks – lowering the gull nesting productivity across the island.

 Only six Great Black-backed Gull chicks were ringed (five colour-ringed). This, together with the seven ringed (only two cr) on 11 June, was a fairly poor showing; suggesting that this species has been less productive than usual this year on Lihou. Several chicks were seen but not caught, but even allowing for this the numbers appeared low.

 Time did not allow a visit to the islets of Lihoumel 1 and 2, although the first islet was covered in fledged or near fledged Great Cormorants and European Shags (30+ birds). Jamie, who has monitored Lihou’ s seabirds for more than 12 years has never seen so many pairs breeding so successfully on the rocks – so this is a very positive sign.

 There was evidence on Lihou of a couple of Peregrine kills – one feral pigeon and a European Oystercatcher.

 We completed out two and a half hour visit with a quick assessment of the gull colonies on the shingle bank and granite outcrops on Lissroy. The dozen or so pairs of Lesser Black-backed Gulls do not appear to have had any breeding success for the second consecutive year. Although adult birds were present in the small colony only two active nests were found – both with a single egg in them. No chicks were observed. Last year the failure of this colony, after producing small chicks, was believed to have been the result of predation by the Snowy Owl. The reason for the lacklustre performance of these birds this year is not known – especially as Herring Gulls in this area had been very successful.

 At least 20 Herring Gull chicks were observed on Lissroy, but they were so large and mobile that we could only ring the relatively few that had hidden in the rocks.

 The total number of gull chicks ringed during this visit was 15 Herring Gulls and six Great Black-backed Gulls.

Once back on Guernsey, I went to Pat Costen’s house to ring the single Herring Gull chick that has resulted from the nesting effort of the pair of gulls nesting on her roof. This is currently very unusual in Guernsey…even in St Peter Port. I was amazed at the mobbing that both adult birds engage in whenever Pat or Pete go into their back garden or try to eat supper on their terrace. The gulls are of course only defending their young, but it is raucous and obtrusive!  The youngster was still a few days too small to be colour ringed (having hatched on 13 June)…so I’ll have to return in five or six days’ time.

 Pat also took me across the road to the neighbour’s garden where another pair of Herring Gulls is nesting on the roof of a large Guernsey granite house. They have been doing this for about ten years. One of the chicks from this nest had apparently fallen off the roof a week earlier, and amazingly it was still alive in the front garden – so the adults must still be tending it. I picked it up ringed it (White 6.AX6) and popped it back through a window onto the roof by the nest and its sibling.

 Another pair of Herring Gulls had even nested (unsuccessfully) on the ground in this property! It was fascinating for me to see for the first time roof nesting gulls in Guernsey. It made me realise just how unpopular such activity is going to be with many Guernsey residents if this habit ever becomes widespread!

  

PKV

 30 June 2010