‘We’ve underrated what these birds can do’: the key lifetime of Skomer’s guillemots

For the previous 52 summers, Tim Birkhead has inched alongside the vertiginous cliffs to rely, ring and observe the guillemots that nest of their hundreds on the Welsh island of Skomer. His life’s work provides unrivalled perception into seabirds in an period of local weather breakdown and likewise reveals the unexpectedly vibrant life of those gregarious birds.

Having crowdfunded his analysis for the previous decade, the emeritus professor is now searching for to boost £125,000 to help his guillemot examine in perpetuity.

“Lengthy-term ecological research like mine are significantly worthwhile in monitoring the impacts of local weather, fishing and illness on seabird populations. Sooner or later our examine will undoubtedly assist reply questions we haven’t but even formulated,” Birkhead mentioned. “My examine occurs to be extremely good worth for cash, costing £12,000 every year. It additionally supplies worthwhile expertise and coaching for younger analysis scientists.”

Emeritus professor Tim Birkhead says he hit the jackpot with guillemots. {Photograph}: Klaus Nigge

When Birkhead, 73, was first dispatched to the uninhabited island as a younger PhD analysis scholar in 1972, he was anticipated to chronicle the decline of the guillemots, whose breeding inhabitants had crashed from 100,000 within the Nineteen Fifties to only 2,000 – largely attributed to grease spills within the area.

As an alternative, he watched Skomer’s guillemots steadily recuperate, growing their numbers by 5% every year to almost 30,000 right this moment.

Throughout the nesting season, 250 chook lovers a day go to Skomer to admire its seabirds. “I might say that 99.5% of individuals come to see the puffins and no person offers a monkey’s about guillemots,” Birkhead mentioned. “I perceive why folks love puffins, they’re stunning and comical, however as a result of I’m focused on behaviour in addition to ecology, I hit the jackpot with guillemots. They dwell in dense teams and their social behaviour is so difficult and so wealthy. There’s gossip, arguments and infidelity – sitting in a cover on Skomer and watching a guillemot ledge is like watching an episode of EastEnders.”

Birkhead has made some fascinating discoveries over time. Guillemots are long-lived birds – his oldest reached 39 – and so they pair for all times. However their monogamous natures are examined by neighbours. Birkhead undertook DNA fingerprinting to see what quantity of chicks have been fathered by the male chook within the neighbouring nest, and found that 7% of chicks are the results of “extramarital” matings.

On one event, he was in a do-it-yourself cover only a metre away from a chook incubating an egg when it started its greeting name. Birkhead scoured the horizon along with his binoculars earlier than selecting up a tiny speck within the air nearly 1km away. “And bugger me, it landed by this chook that has been calling. The chook recognised its accomplice, the place I simply noticed it as a speck.” This expertise impressed his e book, Fowl Sense, which explores how birds interpret the world. “We now have so underrated what these birds can do,” he mentioned.

Tim Birkhead looking out to sea with binoculars
Lengthy-term ecological research are significantly worthwhile in monitoring the impacts of local weather, fishing and illness on seabird populations, says Birkhead. {Photograph}: Klaus Nigge

Guillemots lay only one significantly stunning and unusually pear-shaped egg every year. For years, ornithologists have debated the evolutionary function of this “pyriform” egg form: some say it permits the egg to spin on its axis, whereas others counsel it ensures the egg rolls in an arc, lowering the probability of it falling off the slender ledges the place guillemots lay their egg, with none protecting “nest” round it.

However Birkhead realised each theories have been improper. Any egg form can spin, and the arc {that a} pyriform egg rolls in is wider than most cliff ledges. When he positioned a guillemot egg on a steeply sloping rock, “to my amazement, it simply sat there. I changed it with the razorbill egg which merely wouldn’t keep put”.

As a result of the guillemot egg has an extended straight edge in the direction of a degree, and this rests on the bottom, there may be extra friction, lowering the probability that it’ll transfer.

So the form does cease the egg slipping off slender ledges and, extra importantly, this permits guillemots to nest shut to at least one one other even on uneven cliff edges. Observing the colony’s behaviour because it has grown over the a long time, Birkhead realised that the birds depend on security in numbers and nesting crammed collectively protects their eggs and chicks from predatory gulls.

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A guillemot egg.
A guillemot egg. Photograph: Murdo MacLeod/The Guardian

Globally, seabird numbers have fallen by 70% since the 1950s, and in northern Britain most seabird populations have had significant declines in recent years. More southerly populations – including Skomer – have bucked that trend but after more than 40 years of a steadily growing colony, bird flu struck the colony last summer, leaving the 2023 population down 8%. Birkhead said bird flu was “my worst nightmare”; he fears the impact could be much greater because so many birds die out of sight at sea. “It’s hard to judge what the long-term prospects are. We could see some catastrophe triggered by climate change. This year might be that tipping point.”

The reason for the north-south divide in the British seabird population trend – with northern populations declining with the vanishing of fish stocks – is not fully understood.

“There’s no simple explanation,” Birkhead said. “It tells you that different waterbodies are behaving in different ways [in response to climate] and the birds that dwell in these waterbodies are working in numerous methods. I’d like to know.”

Tim Birkhead on Skomer island off the coast of Pembrokeshire in west Wales in the 1970s.
Tim Birkhead on Skomer island off the coast of Pembrokeshire in west Wales within the Seventies. {Photograph}: Courtesy of Miriam Birkhead

International heating is inflicting hotter, wetter and stormier climate, with “unseasonal” storms now putting Skomer throughout the breeding season and inflicting “seabird wrecks” – mass mortality. “Seabirds have developed to deal with these occasional disasters – they’re very long-lived,” mentioned Birkhead. “But when these wrecks occur too often, it’s going to have a detrimental impact.”

His research present that Skomer’s guillemots have moved their breeding season two weeks earlier due to local weather change. They’ll bounce again from human-made and pure disasters surprisingly rapidly – one cause being that the birds normally don’t begin breeding till they’re seven years outdated, however when populations are worn out 4 or five-year-old birds will step up and begin breeding.

However Birkhead fears that within the long-term the inhabitants will undergo due to such disruption, and it’s not but recognized how the local weather disaster will have an effect on fish shares in southern British waters.

“Due to what’s taking place additional north, I’ve at all times thought there’ll come a degree when issues go pear-shaped for the guillemots of Skomer,” he mentioned. That’s another excuse Birkhead hopes he can elevate sufficient cash to fund his research in perpetuity.

Guillemot flying with fish in its beak
Guillemot populations could undergo with the vanishing of fish shares. {Photograph}: Klaus Nigge

“It doesn’t look nice for any wildlife. Human-made elements are consuming into our pure ecology, it’s simply so unhappy,” he mentioned.

Climbing the cliffs to review seabirds is hazardous – a falling rock the dimensions of a VW Beetle as soon as rolled down the cliff and landed on a ledge 2 metres from Birkhead – however he’s decided to proceed to assist his analysis scientists on Skomer for so long as he can.

“I’m keen about Skomer,” he mentioned. “In Might the whole island prime is roofed in bluebells. As you get off the boat you’re hit by their scent. Six weeks later the bluebells have been changed by acres of pink campion. It’s stunningly stunning.”

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