Grassholm Great for Gannets

As we powered through increasingly choppy waters off the Pembrokeshire coast of south-west Wales - warmed by the sun one minute, soaked by salt-laden spray the next – the centuries-old proverb ‘no pain, no gain’ came to mind.

I have to admit I don’t travel well on water and even dislike crossing the English Channel on a ferry, unless conditions are mirror calm. Bouncing up and down in a relatively small boat on the open seas is certainly not my idea of fun

I gritted my teeth, pulled the hood of my Berghaus coat tightly down the sides of my face and prayed the buffeting would soon be over. 

After what seemed like an eternity, our destination – Grassholm - began to loom ever larger on the horizon. From a distance, the tiny island resembled an iced bun or a gleaming white, paint-sprayed driveway marker stone.
Close-up, the ‘white’ was revealed to be literally tens of thousands of gannets – the world’s third biggest breeding colony for this species.

Only conservationists are allowed to set foot on Grassholm, so I had to make do with observing and photographing the birds from the boat.

After approaching to within one or 200 hundred yards of the cliffs, the captain turned off the engine of his Thousand Islands Expeditions vessel and left us to marvel at the truly breathtaking sight. There were birds everywhere: on the bare rocks incubating eggs, diving like torpedoes into the sea to catch fish, returning to their nests with seaweed dangling from their long, dagger-like bills and wheeling high above us. The cacophony of sound was as deafening as the smell of fish was pungent. 

Situated a dozen or so miles offshore, Grassholm is one of the RSPB’s smallest and remotest nature reserves. When the island was acquired by the charity 60 years ago, in 1948, there were around 8,000 pairs of gannets on Grassholm. Today there are 32,000 pairs – 12 per cent of the global population.

The reason Grassholm is so popular with gannets is because it is remote, exposed, windy and free of ground predators, such as rats.

Gannets can be seen on and around Grassholm for most of the year. The breeding colony is probably empty through most of November, December and January, although the first birds may start to appear in the latter month.

“It is not 100 per cent clear where these birds spend the winter (somewhere in the western Atlantic), but GPS logging work currently being undertaken will improve our knowledge of their movements, RSPB warden Greg Morgan.

“Young birds are known to head much further south, as far as Africa. Many gannets do not return to the breeding colony for several years, using this time to perfect fishing skills.”

Gannets are big, streamlined birds with a wingspan of five-and-a-half feet and a weight of three kilograms. They don’t breed until their fifth or sixth year and rear only one youngster. Despite that, gannets are highly successful breeders, three-quarters of all colony nests successfully fledging young.

Adult birds feed at varying distances from Grassholm. Recent research revealed that some birds travel as far as the south coast of Ireland – a round trip of 800 km in 48 hours. Most, however, were found to be feeding off Cornwall and the South West approaches. 

Gannets plunge into the sea from a height of around 15 metres, folding back their wings just before hitting the water. A feeding frenzy is a sight to behold, countless birds diving into the water all at the same time. How they manage to avoid hitting one another is one of Mother Nature’s many little mysteries. 

Gannets’ striking white plumage enables them to see others of their kind from a considerable distance and home in, like bees on brightly coloured flowers, when a good feeding area is found. Although they eat many different kinds of fish, gannets prefer mainly herring and mackerel.

Landings on the island were stopped 10 years ago because the last remaining safe place for people to view the birds without disturbing them was taken over by breeding gannets!

As far as Greg is concerned, however, a boat trip around the island “provides a much more intimate experience, as you can observe the gannets behaving naturally and experience the sights, sounds and smells in comfort and safety. It is impossible to leave disappointed.” To him, Grassholm is “one of the wildlife spectacles of the world.”

After too brief a stay, we headed back to St Justinian’s on the Welsh mainland – all richer for the avian experience we had been privileged to share.