Jethou

11 June 2014

Once again with the kind permission of Dr Ogden, and the very helpful co-operation of Bill Bayley, the small Seabird Monitoring Team travelled across to Jethou at 0800 on a lovely warm, dry and calm summer’s day. The team for this visit was Chris Mourant, Phil Alexander, Carolyn Brouard and PKV. Before starting work, we enjoyed a cup of tea, making sure to drink plenty of fluid before setting out into the heat and sunshine.

The priority for this visit was to try to get a reasonably accurate census of the breeding activity of European Shag on what has traditionally been the Channel Islands’ stronghold for this species. This involved an anti-clockwise circuit of the Jethou coastline, before ascending the two offshore islets of Grande Fauconniere and finally Crevichon.

Unfortunately it is now hard to remember a good year for Shag breeding in the Bailiwick, and 2014 is no exception to this new trend. In fact it is a diabolical year for breeding and productivity on Jethou. Although not all areas were visited (the top rocky ridges and the north-east corners of Jethou were not surveyed), only 40 nests were recorded for shag, and of these 18 were empty (and had not contained chicks). Only one nest with three chicks was recorded, with 14 nests containing two chicks and the other seven just a single chick. In total 24 chicks were ringed.

Jethou is not alone in such poor breeding success (again!) for shags. As predicted at the start of the season the prolonged severe winter storms, and the extensive murky nature of much of the sea in the region through the year, has clearly severely impacted this species’ ability to breed. The occasional such year is not that unusual and long-lived seabird species are adapted to cope with this. However, the regularity of such poor years locally in the past decade must now be resulting in a strong decrease in population size. There is sufficient evidence now to confirm that European Shag should be one of the seabird species of conservation concern in the Bailiwick of Guernsey.

Having scaled Grande Fauconniere and Crevichon many times over the last three decades, I am personally saddened to see what a lifeless place Grande Fauconniere in particular has become for breeding seabirds. Apart from Razorbills, which appear to be doing well on the sheer cliff faces, Grande Fauconniere is almost devoid of breeding birds. There were only 12 shag nests on the rock (of which eight were empty!), and while a few adult gulls were present no chicks were seen.

Chris, Phil and I all believe that the current weather-related problems are being strongly exacerbated by a very significant  problem with Brown Rats on Grande Fauconniere and Crevichon, as well as the main island of Jethou. We have observed rats in broad daylight in all the seabird colonies, and there is ample evidence of rat burrows and droppings in all the areas too.  Unless this problem is addressed it is difficult to see how ground and burrow nesting species (including the few Atlantic Puffins) are going to have a secure future on the island.  Interestingly the Island of Lihou has experienced similar problems with Brown Rats and has instigated an eradication programme over the last few years which seems to be providing positive results albeit that it is still early days.

On a more positive note, we did observe 24 Atlantic Puffins around the north-east coastline of Jethou. Only one bird was seen flying to or from the land so it is unclear whether these birds are nesting this year. On Burhou, Alderney the puffins returned almost a month late this summer and up until the end of May very few were attempting to breed, which is almost certainly one of the consequences of the severe winter storms, which led to the Great Seabird Wreck in the region when more than 50,000 seabirds (mostly auks including puffins) perished of exhaustion/starvation.

After the very good breeding season for gulls on Jethou in 2013, this year seems to be much more mixed with a return to largely failed colonies around the island (as in 2012). The notable exceptions to this are the beaches in front of the house and by the burner, both of which looked as productive as ever. A quick walk along the top of the house beach resulted in 19 Herring Gull chicks being colour-ringed with a slightly larger number of chicks currently being too small to ring. We will hopefully ring these birds on the second visit in a fortnight’s time.

Very few Great Black-backed Gulls appear to be successful this year, with only five chicks being located all around the island (including Crevichon and Grande Fauconniere).

While on the island I took the opportunity to record a few more of our colour ringed gulls, and managed to locate 14 Herring Gulls (including two birds which had been ringed in 2010 and 2011 respectively as chicks on Jethou). The other Herring Gulls had all been ringed in Guernsey as full grown birds between 2010 and 2014. The single colour-ringed Lesser Black-backed Gull observed had been ringed several weeks earlier at Chouet landfill.

To finish on a more positive note, the Little Egret colony on Crevichon does appear to be going from strength to strength. As soon as we looked down at the colony we knew that our visit was too late to ring any chicks this year, because there were c 15 full-grown fledglings standing on top of the elder bushes. Looking from a distance we estimated that this heronry now contains at least 20 pairs of Little Egrets.

With our survey work completed an hour early; Bill very kindly gave us a fast ride back to Guernsey on the Jethou Express (RIB).

 

 

PKV

12 June 2014