Great Blackbacked Gull
Why this seabird giant is really a ‘bird of prey’
Mention the phrase ‘bird of prey’ and it is highly likely that the thoughts of many birders will turn to majestic eagles, soaring buzzards, dashing falcons and floating harriers. But should they also be thinking of giant gulls?
The Great Black-backed Gull is huge; it is the largest gull in the world, weighing in at just under two kilograms and with a wingspan of around 160cm (a little more than five feet) it dwarfs most British birds. It even makes Buzzards look small.
It is also a top predator. It might not have the lethal talons or hooked beak of a raptor, but make no mistake, the Great Black-backed Gull is a bird of prey in the true sense of the words. Yes they scavenge, yes they exhibit kleptoparasitism (forcing other species to give up food), but they are also skilled predators, regularly hunting and killing their own prey. Whether they are plucking fish out of the sea, snatching Puffins out of the air or swiping a rat off a rubbish tip, the Great Black-backed Gull is an awesome hunter capable of taking a huge range of prey items.
I love watching these large birds. Their contrasting black-and-white plumage gives them a striking appearance as they ride the air over the waves of the sea. On the shore, their size becomes apparent among the other, smaller, gulls. Herring Gulls have a reputation for being fearless snatchers of crab sandwiches and chips, but when they are next to a Great Black-back, they show the utmost respect for their much larger relatives. You won’t find a Herring Gull helping itself to a Great Black-back’s meal, Humans are a far softer target!
Gull identification can be a real nightmare for many birders, but adult Great Black-backs can easily be told apart from other species, by not only their bigger size, but also their colour scheme of contrasting black back and wings and pure white body. They are stocky birds, with thick necks and a large, heavy and fearsome looking bill. There is nothing slender or delicate looking when it comes to these birds. Lesser Black-backed Gulls, which are more closely related to Herring Gulls, can have variable plumage, but the ones that we get in Britain generally have slate grey backs and wings, rather than
the black of the Great Black-backs. They also have yellow legs, while those of the Great Black-back are pink. Immature birds though, as with gulls in general, can pose more of a problem when it comes to identification. The size of the bird and the size of the bill are important ID features, but the best way of identifying them is to get to know them through careful observation. Sitting out watching gulls with bird guide in hand, is the best way of learning your gulls.
Head to the coast
Great Black-backed Gulls can be found all around our coasts during the breeding season, although the majority of them are found on our westerly shores. During the winter, the resident population is joined by birds from elsewhere, more than doubling the numbers of these magnificent birds – this is the time of year when they can be found inland, particularly in the eastern half of the country, where they can turn up on reservoirs, rubbish tips and even farmland. If you have a winter gull roost near you, it is likely to have Great Black-backs in it.
The birds that join us for the winter mainly come from Scandinavia and Iceland, where the species breeds in large numbers. They are also found breeding on the North American Atlantic coast, from the Arctic Circle down to New York and New Jersey, where they are a common sight on the large rubbish tips. Although the birds that breed in Britain are mainly considered to be sedentary, some do travel surprising distances; ringing records reveal one bird, that was ringed as a chick, turning up alive and well just six months later in the middle of the Arctic Ocean more than 1,600 miles away!
It is their predatory nature, combined with a large dash of piratical behaviour, that draws me to watch them time after time. In flight, they are simply majestic. At first they can appear to be simply flying along without a care in the world, but the slow deliberate wing beats are actually enabling the bird to take in all that is happening around it. They are watching what other birds and animals are doing, waiting for an opportunity.
That opportunity can be purely predatory, swooping on to an unguarded chick, or chasing and tiring out a flying duck, until it succumbs to the constant attack of that fearsome bill.
It can be opportunistic, noticing a pod of dolphins and recognising that their behaviour will force fish up to the surface where they can be easily snatched. Or it can be pure piracy, forcing another bird to give up its food.
I have watched, with an ironic smile on my face, as a Great Black-backed Gull harried and chased a Herring Gull until the smaller species regurgitated the fish that it was carrying, mirroring the Herring Gull’s own often used technique of obtaining food from others. There are records of Great Black-backed Gulls even forcing Peregrines into giving
up their prey. It might seem incongruous that this magnificent flyer and hunter would be forced to yield to a gull, but a Peregrine slowed down and encumbered by a heavy prey item in its talons as it flies across open water is an easy target for a bird as big as Great Black-back.
The most intriguing record I have found of Great Black-backed Gulls stealing off other birds involves another raptor, the mighty Goshawk.
In 2013, a Norwegian naturalist watched in amazement as a Great Black-backed Gull moved in slowly towards a Goshawk that was on the ground next to its kill. After much posturing, a fight broke out and despite the Goshawk launching its deadly talons at the gull, the gull held its ground and took the kill. Have no doubt, the largest gull in the world is a serious bird of prey!
Great Black-backed Gulls are magnificent birds and are well worth putting the time in to watch, whether you are sitting on the coast on a summer’s evening watching these large ‘birds of prey’ patrolling the sea and shore, or watching them battling the wind on a winter’s stormy day, Great Black-backs will always provide you with great birding experiences.
Great Black-backed Gulls are coastal breeders
Herring Gulls have a reputation for being fearless snatchers of crab sandwiches and chips, but when they are by a Great Black-back, they show the utmost respect for their much larger relatives
As with most gulls, the sexes are similar, though males tend to be larger
Great Black-backed Gulls will eat just about anything they can get their bills round!