Gulls – a worldwide success story

Please consider the images to be copyrighted and ask permission to use or reproduce any of them. Thank you, DEClapp

Gulls of all sorts, about 50 “species”, if laid out next to each other on a very long table, species after species, would pretty much grade from very white to nearly a complete dusky brown. In addition there are a few that have lots of really ebony black feathers. These black feathers are in a very similar pattern to the gray feathers we see on another swath of gulls. In other words they are an evolutionary work in progress; similar, different, overlapping, developing, adapting. They can be seen to have similar relatives and many share similar feather patterns from group to group, but vary in size, geography, and specific features (like the size and coloration of the bill, legs, or eyes). They are all gulls and there is no mistaking that – but they are all different in a kaleidoscope of ways.

Avian taxonomists work to combine and/or separate the, often similar looking populations. The recent ice ages created geographic populations separated from their relatives by many thousands of years of intrusive ice. Tongues of glacial ice separated populations as tundra and mountain were inundated and icy fissures created. When the ice melted back they didn’t share the same looks or language – they had adapted to their new home and its requirements. They are a hardy group with a greater number of species (or types) north of the equator than are found south of it. But they are found all over the world including the South Pacific, Australasia, New Zealand, South America, and Antarctica. There are more types north of the equator; most likely because the Northern Hemisphere has more land and the glacial epochs divided it into more separate parcels than were seen in the Southern Hemisphere.

I am going to insert a whole gaggle of images that are mostly North American in origin. However, the birds are not so neatly arranged in real life. The birds of northern Canada can overlap with and often breed with populations in Kamchatka and Siberia to the west and Iceland and Scotland to the east. In general, gull populations have a breeding fidelity to specific sites and geography; but they can fly and are strong flyers. Hence there can be unexpected gulls found here and there at any given moment. I will try to arrange them by size, coloration, and closest relatives but that may not be a perfect approach or even doable. Enjoy them, appreciate them and marvel at the skills and adaptations they have developed during the last several hundreds of thousand years. They are pretty cool despite the cultural denigration we assign them, mostly because they are opportunistic feeders and we find them in landfills, trash tips, and dumps as well as fast-food parking lots. For the most part they are hardy and hard working. Oh, by the way the term “sea gull” is meaningless. Many of the gull types are ocean going and live along the edge of salty water, but there are many fresh water gulls and some that are much happier in the prairie-lands than they are at the beach. They are mostly tied to the water but it isn’t a requirement nor is it universal. Also, like many animals, the breeding and wintering habitats are not always similar.

When you go out looking at gulls note the feather color and pattern, compare the size to other common birds, look at the bill and its size, pattern and color, note the time of year as things change in breeding season, look at the eye color, and especially the leg color. Now let’s take a look at a few of our gulls.

The sort of typical gull for most people in the USA is the Herring Gull (HEGU). In the spring the adults (about four years old and older) lose the grayish head feathers and become rather aristocratic in appearance. They often have a mark on the lower mandible and grayish pink legs. Thisis a pretty large bird and among the larger gulls. In most places and in most cases they nest in loose colonies and raise a very dark young or two.
They are opportunistic feeder like many gulls and they have been well studied at landfills and garbage tips. In the US we began to cover our trash only within the last 25 years or so and this closed off usual and productive foraging sites for gulls. On our Christmas Bird Counts we will now get 2-300 gulls in places where we once would count 2500 or more. The gull in this image is still flecked with the winter’s gray feathers on the head and nape. Determining the age of gulls is not always easy as it takes the larger gulls four years to reach maturity and the smaller ones average about three years. Each year they will alter their appearance from dark as a juvenile to splotchy grayish as an adolescent and then two years becoming more and more adult-like. There are many, many birders who never bother to sort out all the gulls.
The Great Black-backed Gull is really quite a big creature, with a body about the size of a Canada Goose. They have become quite common along the North Atlantic coast line and are expanding their range southward each year. As with most gulls they are opportunistic feeders and will scavenge, catch fish, and can swallow most alcids (Dovekie, Murres, Puffins) whole if the opportunity arises.
In Europe the Herring Gull has taken another form and the Great Black-backed Gull doesn’t occur, but there is a gull about the size of a smallish Herring Gull and patterned somewhat like a Great Black-backed Gull – the Lesser Black-backed Gull. This widespread European species has more of a charcoal colored mantle (not deep black) and yellowish legs. They are probably nesting in the Canadian Maritimes and will soon be a bit more common down here in New England. It is presumed that the Canadian birds were Icelandic birds that moved west.
The same shape and appearance is also found in a northerly gull with no dark feathers at all; the Iceland Gull. This is an adult with a very pale gray mantle. As youngsters Iceland Gulls are often quite light overall. The pattern of feathering, the shape of the gulls, and the feeling one gets looking at them all point to birds with a common heritage. These populations (or species or types or race or genomic types) probably share common relatives going back into the last Ice Age. We have been melting that ice for 10-15,000 years but the Ice Age began over 2.5 million years ago. That is plenty of time for populations to be isolated and then adapt to their “new” environmental circumstances. That is evolution – a matter of surviving in the way the environment demands, fosters, and allows.
Oh yes, there is a bigger gull that is similar in size to the Great Black-backed Gull but is also white – the Glaucous Gull. This is most likely a first year bird; about 4-5 months old that I photographed along the Connecticut coast. It was hundreds of miles from where it was raised and hundreds of miles from where it would breed, if it ever got home. Generally speaking gulls are widespread and strong fliers and their penchant for eating whatever and wherever allows them to travel in all directions for great distances.
Another gull that we see throughout central and Eastern North America is built along the same pattern as the Herring Gull. It is smaller, more delicate looking, and has a distinct ring around the beak. It is aptly named the Ring-billed Gull. This is not a salt water gull but a gull of the prairies and lakes of the central US and southern Canada. However we do see them in large numbers in the winter after they migrate out of the mid-west via the St. Lawrence River to the Atlantic and then spill southward along our sandy saltwater shoreline.
There is of course a European or Eurasian gull of some sort as it probably isn’t familiar – in reality this picture is of a Mew Gull taken in Alaska. Step out of yourself for a moment and become an observer well above the north pole. Now, looking down at earth from what we think of as the top, we can see that the continents of North America and Asia almost touch; and there are plenty of large islands and icy patches that do (in fact) connect the land masses. So gulls and other northern species have the opportunity to mingle and hybridize. Some hybrids may be better suited than either of their parents and eventually form a “true-breeding” species.
Another of the very northern gull forms can be seen in this delicate looking Ivory Gull. There are many smallish populations of gulls in the Arctic (Ivory, Kumlien, Ross’s, two Kittiwakes, Sabine’s and Little among them) and we rarely see these species in the southern parts of North America, but they do occasionally wander through. This individual Ivory Gull was walking the beaches at Race Point and was not at all concerned about what or whom. was on the beach with him. I guess if one is to live with seals, walruses, and polar bears a few people on the beach are not a big deal.
This rather typical looking gull is an adult with grayish wing tips and mantle. It is a rather common gull in the far Northwest. The Glaucous-winged Gull is a common resident of Alaska.
There are smaller gulls as well – these are pigeon-sized gulls called Bonaparte’s Gulls. They nest in the Canadian tundra and taiga and we see them along shore in spring and fall.
This is an action shot of Bonaparte’s Gulls resting and loafing along shore during migration. In breeding plumage the ‘Boney’ has a black head like the two species shown below. In the fall they lose the head coloration, retaining but a smudgy spot on the cheek.
These black-headed gull are Laughing Gulls; a very common bird south of New England along the Atlantic. It is now expanding its range northward and we see it regularly in the summer now. They are medium-sized, about the same as a Ring-billed Gull.
Laughing Gulls migrate south to the warm coast of the Carolinas and Florida in the winter. They also (like the Bonaparte’s Gull) lose their black heads and retain a smudge. As you might now expect there is a similar (but different) species called the Franklin’s Gull which can overlap with Laughing Gulls in most of eastern USA.
This is a winter patterned black-headed gull that is actually named Black-headed Gull. This is a regular annual straggler to the American Northeast but is really a European species. This one was hanging out in a parking lot near the Sagamore Bridge and Cape Cod canal.
In breeding plumage, which this individual is approaching, the head is becoming black with a brownish hue. A nice looking gull.
The reddish bill is another characteristic of the Black-headed Gull.

These are representative gulls of the northern hemisphere. In the south there are fewer species, but they also range in size from smallish (like Australia’s Silver Gull and New Zealand’s Red- and Black-billed gulls). They are hardy, bright, and opportunistic. they have been marvelously successful over the past few million years and they offer us a look at speciation/evolution in action. All in all they are much cooler than we usually credit them.

3 thoughts on “Gulls – a worldwide success story

  1. Hey, David. Great article on gulls. There were Black headed
    Gulls at Grays Beach yesterday. It was nice to see them.
    Some warblers coming through now. I am feeling spring.
    Our paths should cross soon, I hope.
    In the meantime, my address has changed and I am now
    freedomfinallyrings31@gmail.com

    Like

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