The Humps, Herm

23 June 2014

Chris Morris and Sea Fisheries staff once again kindly took members of the Guernsey Seabird Monitoring Team to The Humps to continue the monitoring of the 2014 seabird season. The small team composed of Chris Mourant, Paul and Catherine Veron set off at 10.00 from St Peter Port harbour in the Leopardess.  A good forecast promised a hot day ahead with calm sea state. 

Once the Leopardess was safely moored at Rosiere, the seabird team was transferred by RIB to Godin, the innermost of the four Humps. A large flock of Common Terns could be seen flying around the islet, indicating that they were likely to be breeding on this island.  A smooth transfer from RIB to the islet was achieved, but in view of the terns’ presence, the team was keen to keep disturbance to a minimum.    With such a small monitoring team, and with priority being given to ringing Shags and Guillemots, only one person was able to search for Great Black-backed Gull chicks on Godin. The Tree Mallow on Godin was very tall and dense this year (one of the most verdant years in memory!), and with the centre of the islet effectively out of bounds because of the large cormorants wandering in the mallow, it proved to be a real needle in a haystack job. In the end it was perhaps surprising that as many as four chicks were found and colour ringed. Many more chicks must have remained undiscovered.

A total of ten Shag chicks were ringed on Godin.  A few nests still held young too small to ring. An adult Puffin was evident in its usual burrow on the Guernsey facing slope.

The team was delighted to find the Common Tern colony on the southerly edge of the islet, containing approximately 40+ pairs with nests containing eggs and freshly hatched chicks.  A return visit in two weeks’ time would be useful to ring these pulli. This colony appears to have nearly doubled in size since first breeding on Godin in 2013.

The team returned swiftly to the RIB noting the quick return of the Common Terns and seabirds once the team was down by the water’s edge.

The RIB skipper then took the seabird team to Longue Pierre, landing on the boulders on the north east tip.  With no Great Cormorants or Common Terns evident on this islet, the team had a little more time available to them.     A survey of the north east end of Longue Pierre resulted in a few Shag chicks being ringed as well as the first Guillemot chick, which was sheltering under the same boulder.  The Guillemot colony to the furthest north east edge was not approached (due to concerns for bird safety) but the colony on the top of the island at the northern end was investigated and also had Guillemot chicks, which were large enough to take a ring.  A few more days and some of these larger chicks would be ready to fledge.  Further evidence of Guillemot breeding success was also found in the centre of the islet under the highest rocks, both under the large boulder which regularly holds breeding Guillemots as well as under several boulders in the near vicinity which do not usually contain Guillemots.  A total of two adults, (plus a further re-trap was recorded - Number H1600),  and seven pulli were ringed.  It was heartening to see good Guillemot productivity on the islet with a very reasonable number of chicks (approximately 20 - 25 chicks were seen in the colonies investigated and no doubt many more were in areas not covered).

The survey carried out earlier in May of the breeding Shags revealed 28 nests.  On this trip we managed to ring 25 large chicks.  At least five large chicks had also been predated.  

The vegetation on Longue Pierre wasn’t quite as dense, although it was still more extensive and thicker than usual, presumably reflecting the warm, wet spring and early summer. Without the problem of large wandering cormorants on Longue Pierre this year, we could take a little more time to survey this islet, and as a result six GBBG chicks were located and colour ringed, along with a single Herring Gull chick. Once again though more chicks must have remained undiscovered in what proved to be a rather difficult visit from this perspective.

This has been another very interesting monitoring trip to The Humps. The significant growth in the newly establishing Common Tern colony on Godin is very exciting news. Cormorants have had another productive breeding season, while breeding Guillemots have been surprisingly numerous and productive.  However, as anticipated, European Shag has had another very poor breeding season, probably due to a combination of the severe, prolonged winter storms and the continued murky state of the sea.  

The difficulty of seabird monitoring with such a small team, working in thick undergrowth was once again noted. This undoubtedly limits both the quantity and quality of the data which can be obtained on these necessarily short visits.



24 June 2014