As we reach July and the majority of viable gannet eggs have hatched on Grassholm, the fieldwork season for RSPB wardens and our research partners can begin. We’ve already completed seabird counts from the boat back in May and early June but we never land to work on the island until chicks are a few weeks old and the risk of disturbing incubating adults has passed.
Even so, the first landing of the season is always a very careful affair, with limited personnel and a sense of trepidation! However, on the morning of 4 July, when I jumped onto the island for the first time since last October from the VentureJet boat ‘shearwater’ things couldn’t have gone better. Firstly, I’d had a stunning ‘puffin and dolphin filled’ journey across St Brides Bay from Ramsey to Skomer, to collect the WTSWW wardens Bee and Ed. My island neighbours had agreed (without too much persuasion I should add) to come and help me that day. We landed effortlessly in the west gut, avoiding our usual landing place because of the guillemots with chicks on the cliff there. The gannets were very calm and as we moved slowly along the colony edge, just the non-breeders lifted off into the northerly breeze. The breeding birds; trying to contend with their large 4-week-old chicks, were a little pre-occupied, only giving us a suspicious side-ways glance as we crept by.
The purpose of two day trips in July is to locate birds marked with individually identifiable rings. In our case these are yellow plastic rings marked with three black numbers. With our research partners from University of Exeter we have fitted 517 gannets with rings since 2010 and it is these birds that we make every effort to re-sight each year. This mark-recapture study allows us to estimate the survival of adult gannets from one season to the next. Early indications are that adult survival on Grassholm is lower than we would expect, especially in females and this study is invaluable in trying to address these concerns. The ring sighting data will allow Exeter’s research scientists to make more accurate estimates and begin to investigate the causes of adult mortality.
It sounds like a relatively simple mission, but don’t be fooled. Brooding gannets have a tendency to snooze for long periods whilst the chick sprawls out underneath them. Sods law dictates the angle of the leg will always be just slightly off, making reading the ring number more challenging. The final digit is often blocked from view by another bird or splatted with guano, smeared with Grassholm dust or stuck tight with down feathers! It takes great determination and patience to decipher the code as my helpers will testify.
We stopped for lunch just as the heat was building and the island’s healthy population of green bottles come out to play with visiting humans and their provisions. Ed kindly fielded the brunt of the attack, it seems his cheese sandwiches with sweet onion relish were simply irresistible! After a successful 5 hours, we’d identified 68 ringed birds and were heading home to our respective islands.
A week later and it was a very early start at St Justinians for my second day trip. Apparently, there had been a sporting event of some significance the night before, which made the 7:30am pick-up slightly more problematic!) My wing-man this week the director of West Coast Birdwatching, David Astins, who I’d also been promising a Grassholm trip to for some time.
We got soaked with spray on the way out, but the landing went smoothly thanks again to the expert boat handling and good humour of boatman Tim Brooke. We were on land by 08:30 and had a good morning re-sighting rings at pace, made easier by the overcast sky and reduced glare from the birds. After lunch, the sun came out, the heat and dust intense. We were hot and bothered by the time ‘shearwater’ returned to collect us but with 70 ring sightings under our belt, I was happy, as was a highly competitive Dave, who was dead set on beating the Skomer/Ramsey warden tally from the previous week!
Thank-you to my excellent field team of Bee, Ed and Dave for their hard-work and company; we’re so fortunate to have such experienced conservationists and birders in Pembrokeshire to call upon.
We spend 90% of net income on conservation, public education and advocacy
The RSPB is a member of BirdLife International. Find out more about the partnership
© The Royal Society for the Protection of Birds (RSPB) is a registered charity: England and Wales no. 207076, Scotland no. SC037654