Lihou Island

16 & 17 June 2014

16 June

With a brisk NE breeze, but warm dry conditions it was an ideal opportunity to check the gull nesting season on Lihou. Chris Mourant, Catherine Veron and I crossed the causeway as soon as it cleared. Working anti-clockwise around the island enabled us to work some of the closest colonies to the paths before many people reached these areas. Chris had also prepared signs this year to advise the public that seabird monitoring and ringing work was in progress.

As has become usual the first gull colony on the anti-clockwise circuit was perhaps the strongest with many young Herring Gulls old enough to take both metal and colour rings. We worked very fast and it was again remarkable how quickly the adult gulls settled back into the colony, before we had even cleared it!

Working around the coast the 2nd beach contained much younger gull chicks with some nests still containing eggs. The rocky promontory clearly had GBBG chicks in the vicinity, but we were only able to locate one of them.

Several more GBBG nests were located with small chicks, but they did not seem to be as many as is often the case. We’ll get a better view of this on our 2nd gull visit in a fortnight’s time. The beach at the north-western side of the island was very good with lots of chicks, although a fair number were too small to ring.

By the time we had worked around to the Venus Pool gulley, we had ringed 40 Herring Gull chicks and five GBBG chicks. As the gulley contains mostly Lesser Black-backed Gulls, which nest later than Herring Gulls, we did not enter on this trip. In addition to ringing 40 Herring Gull chicks we saw at least as many chicks that were too small to ring on this visit.

We decided to split this first visit across two afternoons so we had time to erect a couple of the additional Seabird Breeding signs which have been produced for the island. Several Oystercatchers appear to be nesting all around the island too.

Although there is still some way to go before the gulls fledge successfully, it is a joy to see another successful year (so far), especially after recording so many poor years (before the rat reduction programme and improved roping of the seabird breeding areas).

We did not cross to Lihoumel or Lissroy, but hope to do that tomorrow. As elsewhere in the Bailiwick there are few breeding shags this year, but we do need to record what is on the offshore islets of Lihou.

17 June

With another pleasant afternoon of weather, Chris Mourant and I went back to Lihou as soon as the causeway opened. Today we headed straight out to Lihoumel to see if any more Great Cormorants had survived predation as eggs by the Brown Rats present on the islet. Fortunately there were seven chicks; all the ideal age for colour ringing. These were the only birds left in the nest, as all other cormorants had fledged by this visit. Chris had earlier recorded nine European Shag nests on Lihoumel, a significant reduction from peak numbers several years back. Most of the nests were empty too with the eggs gone. There were, however a couple of chicks old enough to ring. Several pairs of Great Black-backed Gulls were nesting, but these either had tiny chicks or were still incubating eggs. After swiftly recording the seabirds we returned to Lihou.

Continuing from where we left off yesterday, Chris and I completed our anti-clockwise circuit of the Lihou coast. The southern side of the island is not as densely colonised by gulls and they also seemed to be a little younger on average than the birds in the colonies on the west and north sides of the island. We still managed to ring ten more Herring Gull chicks, along with five more Great Black-backed Gulls. The very dirty nests in the area are proof however that there are more chicks in this area, and hopefully we’ll find more on our next visit.

We added another two GBBG chicks from the top of the island. We finished this visit with a very fast look at Lissroy, where we found another five or six active shag nests (most with one or two small young). We also stumbled across a large GBBG chick as we left the islet.

Over the two afternoons we had ringed 50 Herring Gull chicks (half that of last year…but this visit was deliberately made earlier, and there are still quite a lot of chicks that should be the correct age for ringing on the next tidal access). We also ringed 12 GBBGs, with several more young too small for ringing at this time. The small Lesser Black-backed Gull colonies on Lissroy and in the NW gulley were not visited, as these birds are still incubating eggs at present. Numbers do, however, look encouraging at perhaps 40+ pairs?

In summary it looks like another good season for Herring Gulls, reasonable for GBBGs and Great Cormorants (although the latter suffered rat predation on Lihoumel), but very poor for European Shag.  Several pairs of Oystercatchers are nesting in the usual spots around the coastline, but they have not yet hatched chicks.

 

PKV

18 June 2014