I started my life as a biologist and I am ending it getting deeper into wildlife matters, but for 40 years in the middle when I had to put food on the table I was a pathologist and getting outside with the birds and plants became a weekend hobby for the most part. As a consequence I have excellent visual discrimination, I can look down a microscope at a section of, let’s say a kidney, and tell you exactly what is going on. Is it healthy or is something nasty and possibly fatal happening in there? To the untutored eye though, it is just a confusing sea of pink with scattered blue dots.
How is this relevant to Gulls, I hear you wonder? Well, to me, despite all that professional visual acuity, Gulls are, even after many years looking at them, still mostly a sea of white with scattered gray and black dots and splodges. They are my nemesis, and I have accepted that I will never be able to comfortably segregate them at sight as some of my friends can. However, I can offer you some pointers that may help you become the “Larophile” you aspire to become and which I will never be. Gulls are very much an ornithological specialism, understood by a unique tribe, and which I will try in what follows to give a couple of entry points to.
But first … Most people, in my experience, actually like to know what they looking at but on the other hand there are quite a few that don’t really care about the details. They are content to go through life enjoying being in the presence of a Sparrow or a bear or a snowberry without knowing anything more than that they like it. I find that lack of curiosity rather hard to get my head around but we are all different and if that works for them, then fine. However I recently read an article (link follows) from which the following quotation spoke to me:
Quote: We experience the world and seek meaning from it. Knowing your way around a wetland or a forest, even identifying an insect or a tree in your yard, is a kind of literacy of nature. Naming living things, like naming ourselves, fosters a familiarity that deepens and strengthens our intrinsic (and now seemingly tenuous) bond with what remains of a more genuine world. We name in nature so that we might use our brains to understand and love the world. Recognizing that the golden insect flying around your yard is a dragonfly is great. Knowing that it’s a Wandering Glider (Pantala flavescens) is to know a world citizen—a dragonfly that kills and mates on the wing, crosses oceans in migration, and is found on every continent except Antarctica. Knowing the difference between Twinflower (Linnaea borealis) and Creeping Snowberry (Gaultheria hispidula) is to know story. It might keep you from stepping on one of the forest’s most elegant plants—with paired, dangling, pink flowers, and named for Carl Linnaeus because Twinflower was his favorite. And it is to know that the tiny, white Creeping Snowberry fruits, hidden beneath the leaves, will bring to your palate the most genuine sugary wintergreen flavor you’ve ever experienced, exposing manufactured versions as artificial insults to the human capacity for taste, experience, and honesty.
And now … The Gulls
Ring-billed and occasionally Herring Gulls will be seen in the skies above the river down the road from where I write, and are easy to identify by most birders as at least being “Gulls”, even without binoculars. The Great Black-backed Gulls are less commonly seen, but can be found on the nearby lakeshore or passing above if you are looking up at the right time. The identification of Gulls is a bit of a dark art, especially of immature birds. On the other hand Gull experts (Larophiles) will welcome you to their ranks if you have a fancy to study the variations between species and enjoy a challenge.
Unlike many songbirds that have distinctive plumage year‑round, gulls are highly variable; their feathers change dramatically between breeding and non‑breeding seasons, juveniles look quite different from adults, and several species overlap in size, shape, and colouration. Subtle differences in wing patterns, leg color, bill shape, and even the way they fly can separate one species from another, yet those clues are easy to miss when the birds are soaring over water or perched on a distant pier. Adding to the confusion, gulls are known to hybridize, producing individuals that blend traits of two species. All of these factors mean that a careful eye, patience, and sometimes a bit of local knowledge are essential for reliable gull identification.
What makes a Gull (NOT a seagull, please, ever!) a Gull though? Gulls belong to the family Laridae, with several traits that set them apart from most other birds:
Coastal and Aquatic Lifestyle – Gulls are strongly tied to water. They breed on islands, beaches, cliffs, and inland lakes, and they spend a lot of time foraging on or near water surfaces.
Robust, Medium‑to‑Large Size – Most gulls range from about 30 cm (small herring gull‑type species) to over 70 cm (great black‑backed gull). Their bodies are stocky with a relatively long, straight or slightly hooked bill.
Webbed Feet – Unlike perching birds that have three forward‑pointing toes, gulls have partially webbed feet for swimming and paddling.
Bill Shape and Color – Gulls all have broad, flat bills that can be yellow, pink, or orange, often with a darker tip. The bill is adapted for a very opportunistic diet—catching fish, scavenging, and even picking insects from the air.
Plumage Variability – This is what I find by far the most difficult to fix in my brain. Gulls undergo dramatic seasonal and age-related plumage changes. Many start out with mottled brown or gray chicks, develop a “winter” plumage that is often duller, and then acquire a brighter breeding plumage with white heads, gray backs, and black wingtips. This cycle is far more pronounced than in most other bird families.
Social, Highly Vocal Birds – Gulls are gregarious and noisy, with a wide variety of calls to communicate while feeding or defending territory.
Adaptable Feeding Habits – They are classic opportunists: fishing, dabbling, stealing food from other birds, scavenging human waste, and even hunting small mammals. This flexibility is unusual compared to more specialized feeders. Everyone must be aware of the propensity to steal chips/fries from the very hands of people just having a snack.
A few examples …
…. noting that all the photos, with one exception, are mine
Ring-billed Gull
(Photo: Baie-D’Urfé)
Ring‑billed Gulls in many ways look similar to Herring gulls. Their name comes from the thin, black “ring” that encircles the base of the bill - a reliable field mark that separates them from other Gulls, especially the larger herring gull whose bill lacks this ring.
They are opportunistic feeders that eat fish, insects, crustaceans, and the eggs or chicks of other birds. In urban areas they scavenge human food waste, which helps them thrive in both natural and heavily modified habitats. Compared with many Gull species, Ring‑billed Gulls tend to start nesting earlier in the spring - as soon as March in the northern parts of their range, giving their chicks a longer period of abundant food before the summer heat sets in. They typically nest in loose colonies on islands, sandbars, or the edges of freshwater lakes. Each pair defends a relatively small territory—just enough to protect its nest and immediate surroundings which permits many pairs to coexist in close proximity. Populations migrate south for the winter, traveling to the Gulf Coast, the Caribbean, and parts of Central America. Some individuals remain year‑round in milder coastal regions of the United States.
Herring Gull
(Photo: Blanc Sablon, QC)
That picture is of an adult Herring Gull, adult plumage being achieved about four years of age - the following image is a second year bird of the same species … see what I mean about ID being difficult? You would barely think it was the same species at all.
Herring Gulls are urban pioneers that are equally comfortable nesting on rooftops and abandoned industrial sites where they take advantage of structures to raise their chicks, often forming colonies that can number several hundred birds.
In Canada, Herring Gulls exhibit a “partial migration” pattern in which birds that breed in the far north (e.g., Nunavut, northern Quebec, and the Arctic islands) typically head south for the winter, moving to the Atlantic and Pacific coasts, the Great Lakes region, and the U.S. Gulf Coast. Those that nest farther south, such as in the Maritimes, may stay year‑round, taking advantage of milder coastal climates.
Their opportunistic feeding habits make them one of the most versatile seabirds in North America that can scavenge heavily on human food waste, landfill material, and agricultural crops. This adaptability has helped them thrive despite habitat changes and urban expansion.
Although Herring Gulls are quite abundant, some local populations in Canada have experienced declines due to habitat loss, pollution, and competition with invasive species like the Great black‑backed Gull.
Great Black-backed Gull
(Photo: Iles-de-la-Madeleine)
The Great Black‑backed Gull is the largest gull in the world, with several traits that set it apart from other gull species. Adults typically weigh 1.5–2 kg (3.3–4.4 lb) with a wingspan of 150–170 cm (5–5.5 ft). They have a thick, hooked bill that is adapted for crushing hard prey like sea‑urchins, crabs, and the shells of molluscs as well as tearng meat from larger birds and marine mammals.
Unlike many Gulls that are primarily scavengers, these are active predators that will harass and steal food from other seabirds, sometimes killing smaller Gulls or Terns to take their chicks. They mostly breed along coastal cliffs and islands of the North Atlantic, from eastern Canada and New England up to Greenland, Iceland, and northern Europe. In winter they disperse farther south to the Atlantic coast of the United States. Individuals can live over 30 years in the wild.
This paragraph about these birds is quoted from a wonderful nature writer living in Orkney - they are apex predators. A link follows the quotation.
Last summer, I watched a black-backed gull drown a rabbit and then swallow it whole. The rabbit was screaming for minutes. Black-backs are infamous for such behaviour; they are pirates, scavengers, killers, often top of the food chain (that is, when sea eagles aren’t around), and they commonly pluck ducklings from their mother’s side, and drown small mammals, and bully other scavenging birds so that they can have the first sumptuous taste of a corpse.
Glaucous-winged Gull
The Glaucous‑winged Gull is found along the North Pacific. The upper parts of adults are a pale gray‑blue (“glaucous”) colour that gives the species its name Wingtips are marked with a clean white “mirrored” pattern contrasting with the darker mantle. Juveniles look different, being brown‑speckled with a dark eye‑stripe - making age identification for people like mea bit of a challenge.
Where its range overlaps with the closely related Western Gull extensive hybridization occurs with mixed plumage features. Though normally associated with rocky shorelines and islands of the Pacific Northwest, some birds have successfully colonized urban harbors, marinas and lakes in parts of British Columbia and Alaska. During the breeding season they are aggressively protective of their nests, chasing away much larger birds, including Bald Eagles that come too close. This aggressive defense allows them to dominate mixed‑species colonies alongside less confrontational Gulls.
Heerman’s Gull
Heermann’s Gull is unusual in having a “backwards” migration pattern: it breeds south of the United States, almost exclusively on the tiny islands of the Gulf of California in Mexico, and then flies northward along the Pacific coast for the non‑breeding season, reaching as far as southern Canada before heading back south in the winter. This opposite‑to‑most‑gulls movement is tightly linked to the seasonal availability of anchovies and sardines along the coast.
Heermann’s Gulls have well‑developed supra‑orbital salt glands that excrete excess salt, letting them drink seawater and stay on salty islands where they breed. While most gulls are opportunistic scavengers, Heermann’s Gulls will spend hours walking along sandy beaches and dunes, pecking at insects, crustaceans, and even plant seeds more like the behaviour of shorebirds. During the breeding season they will steal fish or squid directly from the beaks of larger seabirds such as pelicans and brown pelicans, swooping in with rapid, agile flights. In breeding plumage the adults have bright yellow eyes.
The major problems in the world are the result of the differences between how nature works and the way people think.
Fantastic guide here. The pathologist-to-birder analogy really lands, how pattern recognition in one domain doesn't automatically transfer to another even with trained visual acuity. Been trying to get better at gull ID for a while now and the immature plumage issue is exactly where I get stuck too. That quote about naming creating familiarity is spot on, theres something about knowing it's a Ring-billed specifically that makes observations way more meaningful than just "its a gull."
Excellent introduction to the common gulls in your part of the world. You're right about immature gulls, they really are tricky. I can cope with most of the UK's regular gull species: Herring Gull; Lesser and Greater Black Backed, the misleadingly named Black Headed (which has a Brown Head in Summer and a mostly white head in winter) and Common Gull (which isn't common). But the immatures, particularly of the Herring and closely related Lesser Black Backed are very difficult, though there are people out there who are experts at ageing immature Herring and Lesser Black Backed Gulls. Every year, a pair of Lesser Black Backed Gulls nests on a roof opposite our living room and we enjoy watching them bring up their chicks.