The Science of Birds - Herring Gulls

Episode Date: December 4, 2025

👕 Bird Merch —  Get yourself some bird shirts!~~~In this episode—which is number 126—Ivan Phillipsen heads to the seashore to explore the iconic Herring Gulls whose calls define the soundscape of coasts across North America and Europe. Listeners meet not just one but two species: the American Herring Gull and the European Herring Gull, nearly identical in appearance but with a surprisingly twisty evolutionary backstory.Ivan breaks down what makes these gulls such compelling birds: their “menacing” expressions, complex vocal repertoire, opportunistic diets (including bags of Doritos), and clever foraging tricks like dropping clams from the air and tap-dancing for earthworms. He also looks at how these gulls live and raise their young—forming long-term pair bonds, nesting in dense gulleries, and fiercely defending their territories in ways that some unlucky humans have experienced up close.Once persecuted, then booming, and now declining in some regions, these birds tell a story that’s far more complicated than being “just seagulls.”Links of InterestA Herring Gull “foot pattering” on grass [VIDEO]Link to this episode on the Science of Birds websiteEarlham College - A fantastic place to get an education, especially if you love birds Bird Merch - See the NEW shirt designs!Support the show

Sponsoring the podcast this month is Erlem College. If you or a young birder in your life is thinking about college, you want to put Erlem on your list. Erlum is a liberal arts and sciences college in Richmond, Indiana, and it's a fantastic place to get an education, especially if you love birds and the natural world. The campus sits on a major migration flyway, and it also includes bird habitats like forests, prairies and wetlands. As a student at Erlem College, you'll learn from professors who are truly passionate about ornithology, including an endowed chair, meaning there's a professor dedicated specifically to the study of birds. You'll take classes like field ornithology, conservation

biology, and animal behavior, and join a tight-knit birding community. Erlum's research and travel opportunities are exceptional. Students work on grassland bird conservation in Iowa, conduct research in places like Peru and Papua New Guinea, and join fully funded field courses to places like Namibia. Plus, every student gets up to $5,000 for an internship or research experience through Erlem's four-year college-to-career program called The Epic Journey. Whether you love the outdoors or you're thinking about a career as an ornithologist, I think you really should check out Erlham College.

I put a link in the show notes if you want to learn more, or you can visit Erlem.edu slash birding. Erlem is spelled E-A-R-L-H-A-M, Erl-H-A-M-E-O-D-U-S-Birding. And thanks to Erlum College for sponsoring the podcast. All right, let's get on with the show. Imagine walking on a beach in Norfolk. Northeastern North America. It's a foggy day, and there's a picturesque lighthouse nearby. Picking your way among rocks, shells, and bits of loose seaweed, you're having a grand old time,

taking in the lovely sights and sounds along the strand. And if there's one sound in this part of the world that captures, that evokes the entire vibe, one cultural archetype for an animal sound that says, you are at the seashore. That sound is the call of the herring gull. Or likewise, if you were on the other side of the Atlantic, walking along a beach on the coast of, say, England, you would expect to hear sounds like this. Those British birds, too, are herring gulls.

but of a very different flavor than the ones here in North America. And what do I mean by that? Well, keep listening and we'll learn all about it. The story has more twists than you might expect. Hello and welcome. This is the science of birds. I am your host, Ivan Philipson. The Science of Birds podcast is a light-hearted exploration of bird biology for lifelong learners.

This episode, which is number 126, is all about herring gulls. And notice I said gulls, plural. Today we're talking about not one, but two species. We've got the American herring gull, Larus Smithsonianis, and the European herring gull, Larus Argentatus. I know I've got a lot of listeners out there who are larophiles, as in gull lovers, gull enthusiasts. So to you, I say, you're welcome. But to those of you who are not yet larophiles, well, I'll do my best to convert you. Both herring gull species are large, white-headed gulls with light-gray backs. They're widespread and familiar across their

respective continents. Haring gulls are wily opportunists that eat just about anything, and they occupy a broad range of habitats. Now, I feel it's my civic duty to say, even though these birds are icons of the seashore, remember they are not seagulls, because, at least in scientific technical terms, there's no such thing as a seagull. They're just gulls, man. And there are about 105 species of gull in the world. I already did a full Science of Birds podcast episode about the family Laradie. That was episode 47. Laradie includes all the gulls, turns, and skimmers. Today we're focusing on the American herring gull and European herring gull. Before we dig into all the details of how these birds look, sound, and behave, let's look at that common name. Why are they

called herring gulls. You probably know that a herring is a type of fish in the ocean. There are multiple fish species that people have named herring, but the most famous is probably the Atlantic herring. The Atlantic herring is actually one of the world's most abundant fish species, and it's been a commercially important fish in the North Atlantic for hundreds of years. As to why our gulls are named after this fish, in the 17th century, British fishermen knew these birds as the ones that followed herring fleets. The gulls would scavenge the tasty awful, O-F-F-A-L, the fish waste that was thrown overboard. So herring gull eventually became the common name. But this is a bit of a misnomer. While the name implies that herring gulls have

a specialist diet, they're actually generalist predators and scavengers. They don't have any special relationship with herring, the fish. I mean, calling these birds herring gulls, gulls is like calling our own species the hamburger hominid or the pizza primate. Sure, we eat those things, I mean a lot if we're honest, but it wouldn't be fair to make them our entire identity. Okay, it's time to get into it. Let's talk about the natural history and biology of the herring gulls. First, let's look at the appearance of these birds. As we go through the episode, I'll use the American herring gull as sort of the default. The two species are super similar in many ways, virtually indistinguishable in the field.

So unless I point out something specific about the European herring gull, you can assume that the two species are the same in regards to whatever we're talking about, their appearance, behavior, etc. When the topic of gull identification comes up, I go to my book. bookshelf and grab gulls simplified by Peter Dunn and Kevin Carlson. It was published in 2019 by Princeton University Press. But the American and European herring gulls were split into two species in 2024 after the gulls simplified book was published. The book has just one entry for herring gull, and the book is really just about North American gull species anyway.

What the authors have to say about the herring gull, as it was known in 2019, is that this species is, quote, arguably one of the more confusing gulls in the world, end quote. Confusing to identify, that is. And that's saying something because gulls in general are already a challenge to sort out for many birders. So I'm not going to give you a comprehensive guide on how to identify the American and European herring gulls, but we can cover the basics. and we'll focus on the adult birds since the juveniles and young birds can be even more confusing.

These are large, bulky gulls with barrel chests and relatively long, somewhat slender bills. They range from 21 to 26 inches long from beak to tail, and that's 53 to 66 centimeters. And males are generally larger than females. Otherwise, there's not really much difference

between the sexes. The wings are broad and a little on the short side for gulls. In the gulls simplified book, the herring gull is described as having odd proportions, as in the head seems a bit too small for the robust body. And I like how the authors describe the face of the bird giving the impression of pulled taffy, like the beak and face have been stretched out a bit. I would add that compared to many of their relatives, herring gulls look kind of angry, like they mean business. They have a sort of furrowed brow look,

and the corners of the mouth, the gape behind the beak, turns down a bit like a frown. The gulls simplified book uses the word menacing to describe their expression. And the book also explains that a herring gull walks with a waddling sailor's gate. But back to the bill. It's fairly large and powerful, but also a bit slim for a gull. It works well as a tool for eating a wide range of food items. The bill's color is lemon, cream, or some shade of yellowish. The gonus has a red spot on it. Remember that the gonus, G-O-N-Y-S, also called the gonadial bulge, is the part of the lower bill behind the tip that forms a small bump, a protuberance. As for their plumage pattern, these birds are sort of the classic gull.

Adults in breeding plumage have a white head, neck, body, and tail. The back and upper wing are light gray. The primary feathers on the wings are tipped with black. But within that black, there are some white spots. Ornithologists call these mirrors. The white spots were bars surrounded by black in the wingtip. The legs are long, relative to most gulls, and they're a dull, pale pink color. However, some populations of the European herring gull have legs that are a little more yellowish.

The eyes of herring gulls have an iris that's golden or a pale yellow orange. There's an orbital ring around the eye that's yellow orange or even reddish orange in the breeding season. And the orbital ring is that little bear's skin that encircles the eye. So far, I've been describing what these birds look like in the breeding season. In the non-breeding season, the most obvious difference is that instead of having a crisp white head and neck, adult herring gulls have smudgy brownish-gray blotches on their heads and necks. And the eye looks different too, kind of evil, actually, because it's surrounded by dark eye shadow, and the orbital ring is also dark. That pale yellow eye really pops out against

that dark background, and it looks kind of feral, piercing and harsh, menacing, if you will. One of the only times the two herring gulls species are distinguishable, at least to the trained eye, is when they're young. Juvenile American herring gulls are darker and more uniformly brown than European herring gulls, and the European birds have a more contrasting whitish rump and base to the tail. And I should mention that these species are what we call four-year gulls. Young birds of both species typically pass through about four plumage. cycles, which includes seven or eight distinct plumage states before they reach adulthood. This is a common situation with the way gulls mature.

Large species tend to be four-year gulls, but there are also three- and two-year gull species. I'll talk about the feeding and breeding behaviors of herring gulls in a little bit, but one behavioral trait that we see outside of the breeding season is loafing. Loafing is actually a technical term in ornithology. This is where a group of birds stands or just lasers around in one place for a long time, usually in a safe location like a sandbar or on a rooftop. Loafing conserves energy. It involves minimal activity beyond just basic behaviors like preening or sleeping.

And you know, if you just add in some doom scrolling on social media or playing video games, loafing sounds like what I do most days of the week, when I'm not making podcast episodes, that is. Anyway, herring gulls do a lot of loafing in the non-breeding season. They gather in large groups during the day in open spaces like beaches, 7-11 parking lots, fields, and rooftops. They often mix with other gull species who also like to get their loaf on. And when nighttime comes, herring gulls generally roost on islands or on large bodies of water, flying up to 30 miles or about 50 kilometers to find safe roosting sites. We started off this episode listening to some iconic vocal sounds of herring gulls.

Let's explore these in a little more depth now. The vocal repertoires of these birds are complex. There's still a lot for ornithologists to study about these vocalizations. But there are some known patterns. For example, there's the long call. It's a sort of laughing sound like this. So that was an American herring gull. The long call is the most elaborate sound, consisting of a series of repeated notes given in the long call display,

which involves the bird leaning forward, lowering its head toward the ground, and then throwing its head over its back, stretching its neck out with its bill wide open. The long call and display signal a threat to anyone who dares trespass on the gulls' breeding territory. Here's that long call again. It was recorded in Toronto, Canada. Some other calls are the Mew call, Kek-Kek call, begging call, and copulation call. Haring gulls have something like 12 to 15 different calls.

Here's another American herring gull recording, and I'm not sure which call this is. Next we have a European herring goal in France. And I think this might be an alarm call. This next recording is also from France, and I think this one is a warning call. And last, we have another recording from, you guessed it, France. This is the beautiful cacophony created by about 2,400.

hundred screaming herringolds. They're both in the genus Larus, L-A-R-U-S, which has 25 species. Some other familiar gulls in this genus include the ring-billed gull, Western gull, and glaucus-winged gull. The American herring gull is Larus Smithsonianis. It was first described as a separate species with this scientific name back in 1862. Why Smithsonianis? Well, this was in honor of the Smithsonian Institution in Washington.

in D.C. And when I looked up this explanation, this is what I read about the guy who the institution was named after. Quote, named after James Smithson, 1765 to 1829, illegitimate son of Hugh Smithson Percy, first Duke of Northumberland, mineralogist, chemist, philosopher, with Republican leanings, who left over 100,000 pounds in his will to the USA for the foundation of an establishment for the increase and diffusion of knowledge. End quote. Wow. A rich chemist, philosopher, Republican,

and the illegitimate son of a duke? Old James Smithson sounds like an interesting dude. In case you're wondering, that quote is from the Helm Dictionary of Scientific Bird Names. It's a cool book, but entries from this dictionary are also included for each species on the Birds of the World website. Anyway, it was only about a decade

after Laris-Smithsonianus got its name when ornithologists decided these American birds were just a subspecies of the herring gulls in Europe, which went by the name Laris Argentatus. So the two were lumped together. The specific epithet, Argentatus, by the way, means ornamented with silver, because of the bird's light gray back and upper wings. This name comes from the Latin word Argentum, meaning silver, which is also the root of the country name Argentina. And I didn't know that until I was researching these birds.

And I love that. You never know what birds are going to teach you. Anywho, it took only about 150 years before ornithologists decided to split these birds apart once again. In 2024, so very recently, what had been a single species, the herringull, Laris Argentatus, was split not into two, but into four. species. So the two are talking about today as well as the Mongolian gull and Vega gull. And this, my friends, is where the herring gull story gets convoluted, because it turns out that the systematics of these birds has been one of the gnarliest challenges

in all of ornithology. And by systematics, I mean the study of the diversity of birds and their evolutionary relationships and the classification that reflects those evolutionary relationships. The American and European herring gulls belong to a group of over 20 species known as the white-headed gull complex. And I'm just going to write that down as another possible band name, the white-headed gull complex. Teasing apart the species in this complex has been a real headache for ornithologists for like decades. There's been some progress recently, but it's still rather messy and contentious. More on that in a moment.

There is, however, pretty strong evidence for the recent split between the European herring gull and the American herring gull. And the split is agreed upon by many authorities. But the big twist in today's story is that these two gull species are not each other's closest relative. Total shocker, by no. The American and European herring gulls are not what we would call sister species. even though they look almost identical and were treated as a single species for ages and ages. This discovery comes from in-depth research

on the white-headed gull complex that used genetic data from DNA. That research was published in 2016 in the journal Molecular Phylogenetics and Evolution. And you know that molecular phylogenetics and evolution is a highly prestigious journal because I, Ivan Philipson, have a paper published in it.

Have I made that joke before? probably. Will I make it again? Almost certainly. But seriously, I do have a paper in that journal. If you don't believe me, look it up. The analyses in that 2016 study suggest that it's actually the California gull, Larus Californicus, that's probably the closest relative to the American herring goal. Meanwhile, the closest relative of the European herring goal is probably the glaucus gull, Larus Hyperboreus. In support of those genetic analyses, there are some behavioral differences between the American and European herring gulls. Way back in 1958, there was this study by researchers Hubert

and Mabel Frings and their colleagues. They found that the herring gulls in France did not respond to the calls of herring gulls recorded in America. Well, duh, they didn't respond because they're French. They don't speak American. I imagine the researchers Hubert and Mabel in France. They roll up on some gulls in their car, probably a little 1958 Renault dauphine with a loudspeaker mounted on the roof. The researchers hit play

and blast some American herringo calls at high intensity. And then those French gulls look over and they're probably like, mon die, what is this horrible noise? How incredibly rude of the humans to play this rock and roll music? How can we enjoy our laughing time with such a racquet? Flawless French accent. So, yeah, those European birds didn't seem to find anything meaningful

in the recorded calls of the American birds. North American birds in that study, however, did respond to recordings of other North American birds. This lack of response in the European population, suggested a degree of isolation between birds on the two continents. Because seeing how birds in different populations respond or don't respond to each other's vocal sounds is one way ornithologists can assess whether they belong to the same species. I want to take a moment to let you know that I just released a bunch of new designs on bird merch.

That's my online store at birdmerch.com, where I sell bird and birding themed shirts. I've been working on these new designs for the last couple of months, and I'm jazzed to finally release them into the wild. They feature birds like The Greater Sage Grouse, Common Yellow Throat, Sanderlings, Pied Build Grebe, and more. Also, when I first launched bird merch, a lot of people kept asking if I was going to offer shirts in women's styles. So by popular demand, I'm happy to say that I've now got some great shirts for the ladies. For now, I can only ship to customers in the U.S. I'm working on being able to sell in Canada, the UK, and more, and I have not forgotten about all my overseas friends.

Anyway, the holidays are just around the corner, so I hope you'll skip on over to birdmerch.com and pick up some shirts, as gifts, or just because. Every bird merch purchase helps support me and the science of birds. podcast. All righty, let's get back to the show. The genetic study published in 2016 also tells us some things about the evolution of the white-headed gull complex. The geological period of the Pleistocene epoch shaped the evolution and distribution of these gulls, with cycles of range contraction and expansion linked to the climatic swings of the ice ages. The Pleistocene lasted from about 2.6 million to 12,000 years ago.

When the ice sheets expanded across North America and Europe, gull populations contracted and became isolated from each other into distinct regions called refugia. These refugia were little pockets of habitat where the birds could survive. Then, many thousands of years later, when the ice melted away, gull populations would expand outward again, spreading back across the continent. Lineages that had been evolving in isolation in their respective refugia suddenly came back into contact. Biologists call this phenomenon secondary contact. Populations were isolated, they evolved on their own paths for a while, then they met each other again and intermixed. Secondary contact. And intermixed they did, our wily gulls.

The genetic relationships among populations in the white-headed gull complex are so complex that they can't be represented on paper by a mere tree with tidy branches representing sharply defined species. Nope. A diagram of those relationships would look more like a web or a net, criss-crossed with connections all over the place. because these quote-unquote species have been interbreeding, hybridizing so enthusiastically that it's hard to know which of them is even a true species. The white-headed gull complex has evolved recently and rapidly, and it's complicated by all this hybridization, and that process is still going on. So these birds challenge our ideas of what is or isn't a species. At the genetic level, populations tend to group together,

geographically in many cases, rather than by our ideas of which species is which. So if gene flow is that extensive in this group, with hybrids flapping around all over the place, what's the justification for keeping them as separate species at all? That's a good question. A tough question. I don't think there's a simple answer to it. In any case, the American herring gull is known to hybridize with at least nine other gull species, like the Cal California gull, lesser black-backed gull, great black-backed goal, Iceland gul, slaty-backed goal, and so on. The European herring gull hybridizes with at least six other gull species. The funny thing is, hybridization between the American and European herring gulls is pretty rare.

But remember, they aren't all that closely related. So we shouldn't be surprised. In nature, we tend to find hybrids most commonly between two species that are closely related. Laris-Smithsonianus and Laris Argentatus have distinctly different evolutionary histories. During the Ice Ages, the Pleistocene, they hunkered down in separate refugia. The American herringole had an ancestral refugium in Central Asia. Meanwhile, the northeastern Atlantic was the refugium for the population that would become the European herringo. The genetic analyses show there's a lot of alleles. or haplotypes shared among all these gulls.

In other words, what you can think of as genes. There's widespread gene flow among the birds in the white-headed gull complex. What this suggests is that in these zones of secondary contact, where the ranges overlap, ecological pressures or sexual selection just aren't strong enough to completely isolate the groups, reproductively. The species boundaries are basically porous.

they're fuzzy. So these birds challenge our whole definition of a species because their evolution is so dynamic and tangled. But hey, I would say that's cool. It's an interesting biological puzzle. Maybe ornithologists will get closer to solving it someday. We'll see. Until then, let's move on to talk about distributions, habitats, and all that good stuff. The American herring gull is very much a North American species. Its large range spans the continent. It breeds as far north as the Arctic in Alaska and Canada. The European herring gull breeds in the more northerly parts of Europe,

from Iceland and Scandinavia to the British Isles, France, and over to northeastern Europe. Both species are habitat generalists. They use a wide variety of breeding habitats, including natural and human-made sites. But they generally tend to concentrate in areas near open water. Breeding habitats include Arctic tundra, boreal forest lakes, coastal cliffs, grassy or rocky islands, salt marshes, reservoirs, and human-altered habitats like breakwaters and rooftops. nests are often placed in sites inaccessible to land-based mammalian predators. Herring gulls are opportunistic in their non-breeding habitats. They have a strong association with sources of human food and waste.

Landfills and other refuse dumps, fishing ports, places like that. When it comes to their migratory behavior, American herring gulls are partial migrants. Adults from southern populations, like the ones on the U.S. Atlantic Coast and the Great Lakes are mainly sedentary. They don't migrate. Northern populations, however, migrate long distances, heading south to the Gulf of Mexico and winter. Some populations of the European herring gull in the north are migratory, moving southwest-west via the Baltic or Norwegian coastline to winter in maritime northwest Europe. They don't fly quite as far as migrating American herring gulls in terms of absolute distance. Southern populations of European herring gull

like those in France and Britain are largely resident. But there are also some resident populations on the coasts of Iceland, Scandinavia, and elsewhere in Northern Europe. The International Union for the Conservation of Nature, the IUCN, has the European herring gull listed as least concern. The American herring goal doesn't seem to have been placed in a category yet by the IUCN, but that's not surprising since it was only last year that it got promoted to full species status. But on the BirdLife International website,

there's a bird they have there as the Arctic herringole, Laris Smithsonianis. It too is listed as least concern. It looks like this Arctic herring goal is the combination of three species. what e-bird, the Clemens' checklist, would have as the American herring gull, Mongolian gull, and Vega gull. In any case, the two species are not currently listed as threatened or endangered, not at the global scale anyway. But the conservation story for these birds is interesting. The American herring gull population has been on a real roller coaster ride over the last 150 years. Looking further back, things like people harvesting their eggs and the next. natural predators would have kept their numbers in check for thousands of years. But things took a

serious downturn in the late 1800s, when they were hunted heavily for the fashion industry, specifically the millinery trade, you know, to make silly hats with feathers on them. American herring gulls eventually became endangered. They ended up as one of the focal species for the early conservation movement in North America. And thankfully, they got some protection. And at the same time, they faced fewer predators like bald eagles, because those predators, too, had suffered population declines. The situation flipped pretty fast. The gulls bounced back, spreading down the Atlantic coast, and they started interacting a lot more with people. They got addicted to eating our food waste and took up the habit of dumpster diving. This led them to being labeled a nuisance and heavily targeted once again.

So you remember how these birds were named herring gulls by fishermen in the 17th century? Well, if we had named them in the 20th century instead, we'd probably call them dumpster gulls or garbage gulls. But the conservation saga isn't over. The situation has now swung back again. Since the 1980s, the American herring gull population has been on the decline, and they're currently being considered for protected status in some areas. Pretty much the same swinging pendulum of boom and bust has happened across the pond to the European herring gull. In fact, in the U.K., the European herring gull is now on the red list of birds of conservation concern.

So what has caused the declines of herring gulls in the last few decades? A couple things. First and foremost is the decline in the availability of tasty garbage. Improved waste management and changing policies have led to landfill closure, reduction in fishing discards, and so on. Basically, there's less trash lying around. That's a good thing for us pizza primates, but not great for the gulls. Second, the predators rebounded too, and they came back in force.

In North America, increased predation pressure from species like the Great Blackbacked gull, bald eagle, and coyote has reduced American herring gull populations. Other threats to herring gulls in general include habitat loss due to sea level rise and increased coastal erosion. Also, collisions with vehicles, offshore wind farms, and entanglement in fishing gear. When it comes to what they eat, our rascally garbage gulls are generalists. They act as both scavengers and predators. Their opportunistic, competitive approach to finding the next meal is one key to their success. Diets of the two species are pretty similar. Both rely heavily on coastal and marine resources.

But they also exploit the resources humans have created further inland. A herring gulls diet includes fish, mollusks like mussels and clams, as well as crabs, insects, the eggs, chicks, and adults of other seabirds, small me. mammals like rats, berries, carrion, and, in case I didn't mention it before, human refuse. Have you ever seen that meme that's a video of a gull sauntering into a convenience store? The bird grabs a bag of Doritos and runs back outside carrying the orange bag in its beak? Well, that is Sam, a European herring gull in the city of Aberdeen, Scotland. He famously pilfered at least 20 bags of chips over several weeks.

always cheese Doritos. The original video of Sam is from like 18 years ago, which makes me wonder, is Sam still out there living his best life? I hope so. So yeah, Sam shows us that herring gulls are smart and opportunistic. Some of these gulls will temporarily specialize in one or a few types of food, whatever is most available in the environment.

Like other goals, herring gulls are able to wash down all those squishy and crunchy food items with a beak full of seawater. They can drink salt water. That's because gulls have special glands over their eyes that allow them to excrete the excess salt. But these birds actually prefer to drink freshwater when they can get it. Herring gulls spend a lot of time foraging in shallow water or tide pools. They're pretty aquatic in their habits. They sometimes make shallow dives to catch fish. They all also forage by waddling along the shore with their sailor's gate, or they patrol the perimeter of the parking lot at the beach, looking for half-eaten corn dogs or whatever.

Both herring gull species have a clever behavior where they'll catch a hard-shelled critter like a crab or clam, and then the gull will fly up high and drop the invertebrate animal onto rocks or another hard surface below. The shell cracks open and the gull gets access to the chewy bits inside. Sometimes a herring gull in flight will repeatedly drop a clam or whatever and then catch it in mid-air, over and over. There are several explanations for this behavior, but one study published in 2002 in the journal Animal Behavior came to the conclusion that the drop-catch behavior is a form of play, particularly in juvenile gulls. It seems they're having fun, just dropping and catching stuff the way a human kid would play with a ball.

Herring gulls, like some of their gull cousins, also get some of their food by stealing it from other birds. They act as kleptoparasites. Food is snatched rudely out of the bills of birds like turns, cormorants, other gull species, or even sea ducks like eiders. Herring gulls are so competitive and aggressive when it comes to food that when they show up on the scene, large groups of other birds feeding at the ocean,

surface will sometimes just give up and scatter. They don't want to deal with the obnoxious herring gulls. One last thing I want to tell you about foraging in herring gulls is a behavior called foot pattering. The bird rapidly stamps its feet on the ground, either in dirt or on grass. It's pretty funny, and it looks like the gull is tap dancing or Irish step dancing. I'll put a video in the show notes of a gull doing this foot pattering, so you can check that out. But what's the deal with this behavior. Why do gulls do this? It turns out that all that tippy tapping creates low-frequency vibrations that travel through the soil. The vibrations mimic the sound of rain on the surface, or maybe even the digging sounds of a predator like a mole.

This causes the earthworms below the surface to freak out. They think they're in danger of drowning or being attacked by a bloodthirsty mole. So the panicking worms move to the surface where, surprise! They get snatched up by the dancing gull. American and European herring gulls are monogamous, and both parents care for the young. The pears usually stick together for their entire lives, and those pairs initially form prior to the breeding season. This happens on a male's territory or in the non-breeding loafing areas. Herring gulls don't really have special courtship displays. They just use a combination of their normal calls and displays.

For example, the female during courtship will give the begging call and make the head-tossing posture. The male might respond with the mew call in posture. He often hacks up some food as an offering to the female. This, you might recall, is called courtship feeding. If the female accepts this steaming little pile of delicious something or other, then mating is usually the next step. The pair of gulls fiercely defend a small breeding territory. This is somewhere between 2 and 30 feet or 0.6 and 10 meters from the next closest neighboring gulls.

The male establishes the territory and he's the one who does a lot of the defense. So territories are side by side in a breeding colony. In natural settings, colonies are found in the Arctic tundra, at small lakes in the boreal forest and in coastal areas featuring cliffs and sea stacks, as well as on rocky and grassy islands. Another name for a gull colony is a gullery. Here's the sound of a gullery in Belgium.

These days there are also colonies in some human environments like rooftops. If a predator or a silly human enters the colony, the herring gulls get all agitated by the perceived threat. They defend their territories by dive-bombing the intruder, or by pooping on it or vomiting on it. The European herring gull has even been observed hitting unfortunate humans with the old double whammy, Poop and vomit at the same time.

Both parents build the nest over several days, and they keep adding vegetation throughout the incubation period. The nest is a simple bowl constructed mostly of dead vegetation or seaweed and various kinds of debris. The inside of the nest is shaped by the birds using their breasts and feet. They choose to build the structure on the ground in a treeless area, often next to a barrier like a log or a rock. And then mom pops out some eggs.

The standard clutch size is three. These are cryptically colored, in other words, camouflaged. The base color is light olive, buff, or greenish, and there are little dark spots or blotches. Both parents take turns incubating the eggs, but the female spends more time on the nest, especially at night. The eggs are laid about two days apart. The first two chicks that hatch tend to be larger, and when food is, limited, these older chicks get more food. The poor little third chick, the youngest and smallest, may struggle or even die if it can't compete. The youngest chick will sometimes,

in desperation, wander away from its parents' territory. And that rarely goes well for the chick. But if it's super lucky, it might get adopted by a pair of adult neighbors. And there was once a case where a pair of peregrine falcons adopted two European herring gull chicks. How crazy is that? Haring-gull chicks are semi-precocial. For the initial few days after hatching, they need brooding to keep warm. However, they're soon able to maintain their own body temperature

and then they can leave the nest. These little buggers are covered in thick gray down and they've got black polka dots all over. They are objectively adorable. Both parents feed the chicks from hatching until they are about 11 to 12 weeks old. Males feed the chicks more often before they fledge. Now remember that the adult gulls have that red spot on the gowness of the bill.

That red spot is a conspicuous target that the hungry chicks peck at. And this triggers an instinct in the parent to regurgitate food into the mouth of the chick. The youngsters fledge after five to seven weeks. European herring gulls fledge a little faster than American herring gulls. The chicks are fed by their parents on the chick. territory for several more weeks, but they'll continue to beg for food up to six months after they fledge. Haring gulls are fairly long-lived birds. The maximum recorded lifespan in the wild is similar in the two species, at about 30 years. So, hey, maybe Sam, the Doritos thief

really is still alive. But I'm not sure anyone knows what the typical lifespan is of these birds. Twelve years, fifteen, who knows? The oldest American herring gull in captivity, lived to be 49, which is exactly how old I am at the moment. So I guess I've proven that I can live at least as long as a herring gull. So whether you spot them patrolling a beach, loafing on a rooftop, or fighting over an onion ring in a parking lot, I invite you to take a moment to appreciate the next herring gulls you come across. Seriously, try to see them through the eyes of someone who loves gulls, a larophile. Because these aren't just generic sea gulls. The American and European herring gulls are two distinct lineages that have survived the ice ages and the ravages of human

hunting and persecution. These birds are clever and adaptable. Sure, they're also loud and obnoxious sometimes, but I think that's part of their charm. And they're also enduring icons who evoke the wild romance of the sea. Well, my fellow hamburger hominids, that does it for today's episode. I hope you enjoyed learning about these birds. I know that some people have a hard time getting excited about gulls. One reason, I suppose, is that the species are rather hard to identify unless you really study them. But hey, you listen to the entire episode, so hopefully your gull knowledge is that much deeper now.

I really appreciate you being here to learn with me. And I appreciate all my amazing supporters on Patreon. Honestly, the time and research that goes into making these episodes is only possible because of the support I get on Patreon. With their monthly contributions, my patrons buy me the time to make this show as good as it can be. So if you want to help me keep the show going for the long term, please consider becoming a member.

Just check out the support the show link in the show notes and your podcast app, or you can just go to patreon.com slash science of birds. You can also shoot me an email if you have something you'd like to share, perhaps the names of your illegitimate children, or what loafing looks like for you on a lazy Thursday night. You can reach me at Ivan at Scienceofbirds.com. This is episode 126. You can check out the show notes for the episode,

along with some curated photos of herring gulls, and they're adorable chicks on the Science of Birds website, Scienceof Birds.com. And just a reminder, if you're looking for some unique bird and bird-themed t-shirts, please check out Birdmerch, my online store. Just go to birdmerch.com. As always, I'm Ivan Philipson, and true fact about me, I'm left-handed. I write and draw with my left hand. But some other things I do just like a normie right-hander.

like throwing a ball, using scissors, playing guitar, and casting spells at my enemies. My dad was also left-handed, and so I assume this sinisteral gift was passed down over the generations, going all the way back to the Pleistocene, when my people shared our ancestral European refugium with, I imagine, a population of cheeky herring gulls. All right, that's enough silliness for today. Thanks for listening, and I'll catch you in the next episode. Cheers. Thank you.