Monitoring Gannets on Grassholm Island

Gannet colony on Grassholm Island RSPB Nature Reserve

There give you a good insight into the work that is involved in looking after the gannets on Grassholm Island.

As well as living and working on Ramsey, Lisa and I are also privileged to look after Grassholm, a tiny 9 ha rock lying 7 miles West of the Pembrokeshire mainland and home to 40,000 pairs of Northern Gannet. It is the RSPB’s oldest reserve in Wales being purchased in 1948; at the time it played host to a mere 7,000 pairs. Today it is the 4th largest colony in the world for the species with around 10% of the world population.

There are no public landings on the island due to the disturbance this would cause. RSPB staff land on a handful of dates during the season to carry out monitoring and research work, the latter with Exeter University. A few days ago Lisa and I landed for the first time this season and spent a few hours carrying out productivity work. This involved mapping several study plots and recording how many incubating birds they contained. When we return in August we will check how many of these nests contain large chicks likely to fledge.

Gannet correctly incubating her egg
Gannet correctly incubating her egg

Most birds were still on eggs but quite a few had small 1 week old chicks and a couple had chicks that were around the 2 week mark and had developed the characteristic white down. When sitting quietly looking through the telescope it was interesting to see these large often quarrelsome birds gently tending to their single white egg. They incubate them under the feet, using their large webs (see photos below).

inexperienced gannet incubating her egg
inexperienced gannet incubating her egg

One bird on the edge of the colony which was probably an inexperienced breeder clearly hadn’t got the hang of this and the egg could be clearly seen poking out of the side of the bird receiving little in the way of incubation and in full view of marauding gulls! (see photo below) The bird was oblivious to its error and even shifted around several times as if adjusting the egg that it must have thought was between its feet where it should have been!