This is recent Times feature article I wrote on the incredible new discoveries of what seabirds get up to far from land, and on the man who first visited seabird colonies with a scientific eye in the 1660s. It’s sometimes still possible to write this kind of discursive essay! This one is about two of my friends from the same research group at Oxford.
Off the coast of Pembrokeshire in south Wales lie two islands, Skomer and Skokholm. Home to more than 300,000 pairs of nesting seabirds, they are wild and raucous, rich in the sounds and sights (and guano smell) of seabird colonies. Every spring the Atlantic Ocean disgorges its birds on to rocky islands around Britain’s coasts to breed. By late summer the birds have vanished. The secret of what they do and where they go is becoming clear.
This summer puffins leaving Skomer will have GPS tracking devices and cameras attached to record where they go and what they do. It was on Skomer and Skokholm in the Seventies that two zoologists came to study the birds. Tim Birkhead landed on Skomer in 1972 to try to understand why the guillemots had declined to just 2,500 pairs (today they are up to 25,000). He has visited the island every spring since.
Michael Brooke arrived on Skokholm a year later to act as warden and study the Manx shearwater, a mysterious ocean wanderer that visits its nesting burrow at night and breeds almost exclusively in the British Isles. He has since travelled the world, studying seabirds on even more remote islands from the tropical Pacific to the Antarctic.
This year both men have written remarkable books that between them capture the excitement of cracking the secrets of birds, and seabirds in particular. Brooke’s Far From Land: the Mysterious Lives of Seabirds recounts in fascinating detail how new techniques such as satellite tracking are allowing scientists to find out what seabirds get up to on and under the sea.
Birkhead’s The Wonderful Mr Willughby: the First True Ornithologist uncovers the life of a scientist at the start of the scientific revolution who first made the study of birds, insects and fish into a scientific discipline with his friend and tutor from Trinity College, Cambridge, the botanist John Ray.
In the Seventies Birkhead and Brooke might just about have seen each other in the distance on their separate islands, but it was back in Oxford during the winter that they would actually meet. Both were studying for their DPhils at the Edward Grey Institute, a university research group devoted to ornithology and named after the one-time foreign secretary (and Oxford chancellor) Sir Edward Grey, who wrote The Charm of Birds in 1927. I also studied at the EGI, as it was known, and came to know both seabird experts. Yet little did any of us dream how much knowledge would emerge by the time we were in our seventh decades.
Consider some of the stories that Brooke recounts in Far From Land. Tags attached to birds’ feathers or legs can now transmit their position and show whether they are flying or resting on the water. Fixed to Brooke’s favourite Manx shearwaters, the tags reveal that the birds travel to near the coast of southern Argentina in winter, via west Africa and Brazil, then return north in spring by a more westerly route closer to the coast of North America. They can easily cover 500 miles in a day.
The migration feats of seabirds are astonishing. An Arctic tern that my friend John Walton ringed on the Farne Islands off Northumberland in 1980 was recaptured and photographed with him in 2010. In those years it had migrated to Antarctic seas every winter, returning to Northumberland each spring, covering almost a million miles. Unlike John, it looked as young as ever.
Brooke recounts how today’s University of Oxford researchers have exposed the idiosyncratic migration patterns of individual puffins from Skomer, each making the same journeys in different winters: EJ09593 goes to Greenland in autumn, then back to west of Ireland in midwinter; EJ99355 goes north of the Hebrides, then south to the Bay of Biscay; EJ47617 heads for Iceland then to the western Mediterranean.
We now know that gannets from different British colonies partition the sea when foraging, with little overlap between colonies; guillemots can dive to 100m, and will even dive to feed at night in winter in almost complete blackness, somehow finding fish; and some young kittiwakes may spend their first year wandering as far as Baffin Bay, west of Greenland.
The stories that are emerging farther afield are even more spectacular. Brooke has studied Murphy’s petrel on the remote island of Henderson, an uninhabited speck that is part of the British Overseas Territory of Pitcairn in the Pacific. It takes 50 days for the petrels to hatch a single egg, with the incubation duty split three ways: male for 19 days, then female, then male again. When Brooke put geolocators on 25 birds he found that some of the off-duty ones travelled in search of food towards Peru, turning back only when about 2,500 miles from Henderson and covering up to 10,000 miles in less than three weeks.
Or consider how a single pair of Sabine’s gulls, nesting in the Canadian Arctic, spend the winter in separate oceans, the female off Peru, the male off South Africa, before reuniting on the tundra the next summer. Or that an emperor penguin may dive as deep as 560m and stay down for up to 20 minutes. Brooke’s book is stuffed with many such mind-boggling feats. To read it is like encountering a new and unknown blue planet for the first time.
This too was what gripped Willughby in the 1660s as he set out to understand the natural world, not by reading Aristotle or the Bible, but by using his eyes. It was a chance remark that led Tim Birkhead to become Willughby’s biographer. He was visiting the family home of Lord Middleton, Willughby’s descendant, when researching the history of ornithology for a previous book. He remarked that of the two Trinity men, Ray was the scholar, Willughby (who died young) the dilettante. Not so, said Middleton with vehemence.
Intrigued, Birkhead returned in 2014 and with Middleton opened the cabinet containing Willughby’s natural history collection. To his astonishment the bottom drawer contained a collection of cracked birds’ eggs inscribed with Willughby’s distinctive hand — the oldest extant birds’ egg collection in the world. Gradually Birkhead was drawn into the life of this extraordinary man, an early member of the Royal Society caught up in the thrill of letting the facts speak for themselves, a scholar of linguistics and a careful dissector of the birds he shot and the insects he caught.
Birkhead is also keen on dissecting birds, although in his case ones that die naturally. Emulating Willughby, he dissected a bittern that struck a power line, finding facts about it that Willughby missed. Some years ago he and a colleague were among the first to describe and explain the enormous length, and explosive expansion, of penises in ducks, and the contorted shapes of female reproductive organs, designed to keep such intruding organs out, unless invited. But that’s another story.
Willughby and Ray were fascinated by seabird colonies — the “remarkable Isles, Cliffs, and Rocks about England, where Sea-fowl do yearly build and breed in great numbers”. They saw, but did not visit Skomer. They landed on the Farne Islands off the Northumberland coast, which I have visited every year for almost five decades (and whose advisory committee I sit on), and saw the same species I see today: “guillimets, scouts or razorbills, coulternebs [puffins], scarfs [shags], Cuthbert duck [eider], annet [kittiwake], mire crow [black-headed gull], pick-mire [tern]” and more.
This is reassuring — that these extraordinary seabird colonies have endured for centuries. Willughby records the systematic exploitation of seabirds in the 1600s. On the Calf of Man as many as 9,000 shearwater chicks were killed each year for sale as food, and the same was true in many seabird colonies. It was similar slaughter that caused the only extinction in the north Atlantic, of the flightless great auk, gone by the end of the 1840s.
Yet the colonies of other birds endured, and Skomer’s guillemots have bounced back from the oil spills that devastated them during and after the Second World War. These spills are now rare — indeed, we may have lived in a golden age for seabirds here. Numbers have possibly never been higher on the Farnes or Skomer, although Scottish seabird colonies have declined badly in recent decades because of a shortage of fish.
Now protected from human harvests, seabirds were also until recently spared the worst ravages of predation by large seagulls, their main predator, since most reserves had a policy of controlling gull numbers. Rats too have been extinguished from colonies such as Lundy and the Shiant islands in the Hebrides, allowing seabird numbers to expand.
In some ways it would have been wonderful to have lived when Willughby did and almost every observation, such as the description of a young shearwater, was new to science (if not to folklore). Yet how much better to live now when the entire world of seabirds, even far from land, is being chronicled in such magnificent detail by scientists such as Brooke and Birkhead.
Tim Birkhead’s research survives on public donations. To give, go to: justgiving.com/fundraising/guillemotsskomer.
The Wonderful Mr Willughby is published by Bloomsbury,
Far From Land is published by Princeton University Press