Lesser Black-backed Gull
This seaside species is a great example of never judging a bird by its name – there’s a lot more to it than you might think...
Dominic Couzens on why there’s more to this seaside speciality than meets the eye
Igive you the Lesser Black-backed Gull, the British bird with the most off-putting name. Lesser – that can mean inferior. Black-back is a clunky rhyme. And talking of rhymes, gull rhymes with dull. In most people’s eyes, that’s exactly what gulls are – boring. They are worse than that. Gulls are noisy and lacking in airs and graces. And for birders, gulls are a nightmare to identify, which is the worst sin of all. Did you think twice before beginning to read this article? The Lesser Black-backed Gull also lives and dies by comparison. Where there is a ‘Lesser’, there must be a ‘Greater’. The Great Black-backed Gull is the bird closest to a Hollywood heavy in a crime movie; the species most likely to have tattooed forearms. It has a proper identity as the largest gull in the world. It swallows Puffins and does other cool but cruel stuff. The Lesser does none of this. It is more closely related to the Herring Gull, another bird with a clear role as the clanging atmosphere-creator of seaside towns, and the bird that shocks Daily Mail readers by stealing chips from holidaymakers, without asking. In comparison with these strong characters, is there something special to put forward for the Lesser? There is. Let’s hear the drum roll for… the bird with the world’s most leisurely migratory journey. Is that accolade enough? Some scientists tracked Lesser Black-backs on their autumn migration (from the Netherlands to Britain, to southern Europe or to north-west Africa), and found that
they only travelled, on average, 27 miles a day. That, for any bird, is fantastically slow – a Swallow exceeds that in an hour. They could almost have walked. The researchers found that the furthest any individual gull moved on migration was 110 miles in a single day, which many bird species exceed while just feeding their young in a 24-hour period. This, however, is for travelling a median overall distance of 745 miles (adults).
Easily distracted
The reason for this extraordinary lack of urgency would appear to be that Lesser Black-backed Gulls are easily distracted – so much so that you can imagine them setting out with the best of migratory intentions in the morning, only to come across a tempting food supply and thinking “Well, this is great, I can always fly tomorrow.” Their recorded journeys were haphazard, almost serendipitous, with frequent changes of direction. If you think about it, to move in a chilled way like this is a smart migration. Speed isn’t always necessary. The very fact that Lesser Black-backed Gulls make long-distance movements down towards the Iberian Peninsula and North Africa for the winter (occasionally even well down the West African coast) is a defining characteristic not shared by Herring or Great Black-backed Gulls. The former do make some movements, but the numbers are not high. Great Black-backs come to Britain from further north, but equally don’t travel in big numbers much to the south of us. Lessers are thus
in their own class as travellers, with their relatively light build and long, elegant, pointed wings. Large numbers are summer visitors to Britain, of the same ilk as Swallows and Cuckoos. However, although many Lesser Black-backs are bona fide summer visitors to Britain, arriving in the spring and leaving in the autumn, not all individuals are; and, indeed, the picture has changed enormously since the mid-point of the 20th Century. Back in the 1940s, very few Lesser Black-backed Gulls could ever be found in Britain in mid-winter – perhaps a few hundred. But since that time, more and more individuals have changed their behaviour and, instead of going south in the autumn, they stay here, instead, now in their tens of thousands. Although nobody is entirely sure why this is the case, it is certainly true that there are more suitable winter roosting sites, with an enormous increase in the number of freshwater gravel pits and reservoirs. At the same time, landfills, a great favourite of these arch-scavengers, proliferated from 1956 onwards, when the Clean Air Act forbade the burning of much rubbish on tips, leading to the availability of masses of organic waste – and Lesser Black-backed Gull heaven. (This itself is now changing, and many Lesser Blackbacks are instead feeding over farmland.)
Leavers and Remainers
The Lesser Black-back is now a classic partial migrant. Among the individuals that breed at a given British colony, some will migrate south from Britain in the autumn and some will stay within our shores. There are Leaver and Remainer camps even among gulls, it seems. Some immature birds in the first year of life actually stay in their wintering grounds for their first and even second summer, not bothering to venture north if they aren’t going to breed. Even among immature birds, however, there are some that remain in Britain for their first winter. This is not the only big migration change in the world of the Lesser Black-backed Gull. Nowadays, it seems, part of the population from Iceland, that would normally come south past our shores, has begun to follow a previously unknown path to winter on the North American continent. Once a great rarity across the pond, the Lesser Black-backed Gull is now found in
every month of the year in North America, across the whole swathe of the Eastern Seaboard, right down to Florida. There are confident predictions that it will soon breed (if it hasn’t already) and colonise the east of that continent. After all, it only colonised Iceland in the 1920s, so why not cross the Atlantic as well? You might think that, in view of this migratory upheaval, the important things in the life of the Lesser Black-backed Gull might instead remain the same – the things of the home. Yet here, too, great changes have been afoot, changes that would almost be unheard of in most species. When it comes to breeding, the Lesser Black-backed Gull is traditionally associated with coastal, flat areas, often with a reasonable cover of vegetation – it tends to prefer more plant growth than its colleague the Herring Gull, for example. So, there are large colonies on marramgrassy sand-dunes in north-west England, and on low islands, and sometimes also on moorland some distance from the sea. Studies have shown that Lesser Blackbacked Gull chicks are better able to conceal themselves from predators in such places than are Herring Gulls, which tend to rely on parents directly protecting their young. Herring Gulls spend more time at the nest during chick-rearing than Lesser Black-backs. What, then, can we make of the Lesser Black-backed Gull’s colonisation of cities, often very far inland (the West Midlands, for example) by nesting on roofs? This was another huge change in this gull’s behaviour that also began in the 1940s, starting slowly but becoming more significant, and still increasing in some areas. There isn’t much vegetation on roofs, but a big plus is that there are few, if any predators. The gulls are especially fond of large industrial sites with plenty of roof area, where they can be colonial. It is a far cry from a windy moorland, or a sand-dune, but it clearly works for this most adaptable of species. When you look beneath the surface of an apparently dreary gull’s life, you find an astonishing capacity to change and adapt: to change migration distances, to alter migration routes, to feed on landfills instead of catching fish from the surface of the sea, to nest on roofs, to colonise new countries and even continents. This isn’t a ‘Lesser’ bird in anything but name. Instead, it has an identity carved out of its very aversion to staying still. It is, instead, the Dynamic Blackbacked Gull.
LOOK BENEATH THE SURFACE OF AN APPARENTLY DREARY GULL’S LIFE, YOU FIND AN ASTONISHING CAPACITY TO CHANGE AND ADAPT