The Shiants, remote, cliff-edged islands off the coast of Scotland, are home to 350,000 seabirds, including great auks, puffins, and razorbills. This is the starting point for new book,. Celebrating 10 species in detail, he describes the incredible resilience of seabirds and the many adaptations that have enabled them to survive and navigate the oceans, while sounding a clarion call for their conservation amid dramatically falling numbers. For me, these seabirds are symbols and embodiments of otherness, the non-constrained world. There is so much on the land where the rest of the living world seems to be dominated and diminished by us, but when you go to seabird colonies there is this pumping, loud, raging otherness. More of them have survived in greater numbers than most other creatures in the developed world, where huge proportions of the animal kingdom have been removed by us. In 1937, my great-grandmother left my father some money when she died. He then gave them to me when I was 21, and in turn I gave them to my son, Tom, when he turned 21. But with about 350,000 seabirds breeding there, including puffins, guillemots, razorbills, shags, fulmars, and great skuas. Through in the 50s, 60s, and 70s, people started to find out that when shearwaters left their northern nesting islands, they headed south, along the western shore of the European continent and North Africa. Only when this amazing modern miniaturized tracking technology was developed enough did people begin to understand that they live a life of everlasting summer. They summer in the Northern hemisphere and summer in the Southern hemisphere. Each year, they undertake these extraordinary figure of eight migrations, following the wind gyres of each of the two hemispheres for 40,000 miles. Another third, she attached a little plastic box with glue to their heads. Inside was a pair of free-tumbling magnets, so the magnetic environment in which the shearwaters were living would be constantly disturbed. The third group, she put a chemical into their nostrils that temporarily disabled their ability to smell. She then took these three groups on a ship about 500 miles east of the place in the where she had taken them from their burrows. The results were extraordinary. The group she had done nothing to flew 500 miles pretty well straight home to the burrows. But the group that had had its ability to smell disabled was radically lost. For weeks, they desperately wandered around the northeast Atlantic, up to the Bay of Biscay, Portugal, and West Africa. That shows it is perfectly clear that shearwaters, in order to know where to go, need to be able to smell. But they are not smelling their nest site 500 miles away;. Somehow, they have a smell map of the ocean so that by smelling a particular patch of ocean, they know where they are and can then decide where to go. It has to do with a chemical called , which is released when i. This is a signal that little shrimp-like zooplankton are present, eating the phytoplankton. People have done experiments showing that if you release DMS, even in tiny concentrations, you. Whether DMS is the whole picture is something else. There are almost certainly other chemical signals across the ocean, which these birds get to know and understand. They have more recently done other experiments, which show that shearwaters and the other tube-nosed birds, like petrels, albatrosses, and fulmars, are dependent on smell but not only smell. There is a problem now. If you leave plastic floating in the sea for over three months, it starts to release plumes of DMS. It clogs their guts, and makes them unable to get enough real food into their stomachs. There are lots of reasons for a seabird not to be in a colony. If you go to colonies, you can find very good nest sites available on a rock but no birds there. Instead they cluster in these incredibly dense gatherings. Guillemots have something like 8 square inches as their defended territory. What evolutionary advantage is served by clustering in colonies, when the dangers and disadvantages are so clear? It seems that the reason that seabirds are colonial is that their prey is so difficult to find. But fish are difficult to find and on the move, so the premium for seabirds is on information. If you can know where other birds like you have been fishing recently, you will want to get that information from them and be in the place where that information is as new as possible, i. So, you cluster as tight and as hard as you can. Gannets are one of the great information-center birds. The premium for getting good information for a gannet is so high that they will risk nearly everything to be at the center when the information comes. And if any other gannet attempts to breed within the reach of a neighboring gannet, it will die. The gannet bill has this incredibly sharp, slashing tip at its leading point, which can take an eye out. This is a world of very intense competition and mobile sustenance. You have to be on the case if you are a seabird. Gannets have amazing capabilities. Their eyes can also change from seeing in air to seeing under water, in less than a twelfth of a second after hitting the sea. They are incredibly evolved things, with this total gangster capacity! Bass Rock is one of the wonders of the world. The number of seabirds in the world has dropped by something close to two-thirds in the last 60 years. About 60 years ago, there were about 1. Now, there are about 500 million. And the reasons they are in decline are entirely to do with us! Hundreds of thousands of birds die every year, caught in fishing gear; nesting sites are destroyed by our development and our dogs, cats, and rats kill many more. They are also declining due to global warming, which is deeply changing With those changes in ocean patterns, the whole trophic structure of the oceans is changing. If you get a change in phytoplankton and zooplankton, of small and big fish, all those things impact the way in which seabirds survive and feed their young. They have tons of resilience built into them. Albatrosses can live 80-90 years, so they can spring back from one failure or disaster for a year or two. But the pace at which ocean systems are changing may be too much for those resilient systems to work. One encouraging thing is that after the great extinction, 66 million years ago, when most life— including the dinosaurs—died, quite a few bird lineages survived. Cormorants, penguins, albatrosses, were all in existence before that extinction and have done marvelously ever since. So it may be that seabirds have an ability to survive the worst that we can do to them. But nobody should be too complacent about that.
