What Eats a Puffin? Predators From Air, Land, and Sea

Puffins face threats from a surprising range of predators, and the danger shifts depending on whether a puffin is an egg in a burrow, a chick leaving the nest for the first time, or a breeding adult returning to a colony with a beak full of fish. The great black-backed gull is one of the most significant predators of Atlantic puffins across their range, but skuas, eagles, foxes, rats, and mink all take their share. What makes puffin predation especially interesting is how dramatically the balance of power can change with small shifts in predator numbers or human activity on nearby islands.

The Great Black-backed Gull

If one predator stands out as the puffin’s most persistent enemy across the North Atlantic, it is the great black-backed gull. The largest gull in the world, it is big enough to kill and swallow an adult puffin whole, and it does so regularly at colonies where the two species overlap. On the Isle of May in Scotland’s Firth of Forth, breeding great black-backed gulls have been increasing since the 1980s, and researchers have documented a corresponding rise in puffin predation during the breeding season.¹ These gulls patrol the edges of puffin colonies, waiting for adults to land with fish or for lone birds to become separated from the safety of a group.

The impact of great black-backed gulls becomes especially severe when a puffin population is already small. On Burhou in the Channel Islands, researchers found that even though great black-backed gull numbers had not changed much since 1969, their predation on a diminished puffin population represented a major addition to adult mortality. When a puffin colony shrinks for other reasons, the predation pressure from these gulls can prevent recovery entirely.² This creates a vicious cycle: fewer puffins means each individual faces proportionally more attention from gulls, which keeps the population suppressed even after whatever originally caused the decline has been addressed.

Other large gull species harass puffins too, though with less lethal results. Lesser black-backed gulls and herring gulls engage in kleptoparasitism, attacking puffins in flight to steal the fish they are carrying back to their chicks. The Burhou study found these attacks were generally too infrequent and too unsuccessful to significantly affect puffin breeding success.² Losing a beakful of fish is a setback, but it is survivable in a way that being eaten is not. The distinction matters for conservation: managing great black-backed gulls specifically, rather than gulls in general, is where the payoff lies.

Skuas and the Ambush Hunters

Great skuas are aggressive, powerful seabirds roughly the size of a large herring gull but built more like raptors in temperament. On Fair Isle, between Scotland’s Orkney and Shetland archipelagos, great skuas have been directly observed hunting puffins through aerial pursuit and on-foot ambush for decades. Researchers and bird observatory staff have recorded more than fifty incidental observations of skua predation on puffins per year from the mid-1980s through 2013.³ The remains of killed puffins are a regular find on skua territories during the breeding season.

What makes skua predation distinctive is the range of tactics involved. Some great skuas chase puffins in flight, overpowering them in the air. Others wait near burrow entrances and ambush puffins on the ground. Puffins are not fast or agile flyers, and their body shape, optimized for diving underwater, makes them vulnerable in aerial pursuits against a predator built for speed and aggression. Arctic skuas (also called parasitic jaegers) harass puffins too, though they more commonly steal fish rather than kill adults. The great skua is the one that poses a genuine mortality threat.

Eagles Over the Colony

In North America, where tufted puffins breed along the Pacific coast from Alaska to northern California, bald eagles are a significant predator. Eagles eat puffins directly and also suppress colony activity simply by being present. On Protection Island in Washington State, researchers have counted as many as 53 bald eagles on the roughly three-kilometer island on a single day during the breeding season, while only a handful of tufted puffins remain.⁴ The sheer ratio of predators to prey on such islands makes the situation almost untenable for a small colony.

In the eastern Atlantic, white-tailed eagles fill a similar ecological role. As white-tailed eagle populations have recovered across northern Europe following decades of conservation effort, their interactions with seabird colonies have intensified. An eagle does not need to kill many puffins to have an outsized effect. The mere presence of a large raptor near a colony disrupts breeding activity, discourages adults from returning to their burrows, and can cause widespread nest abandonment if the disturbance is sustained.

Predators on the Ground

Puffins nest in burrows, which provides protection from aerial predators but makes them vulnerable to anything that can enter or dig into those burrows on land. Rats are the most devastating ground predators at many colonies. Brown rats eat puffin eggs, kill chicks, and can even attack incubating adults in the confined space of a burrow. Because puffins evolved on islands that were historically free of mammalian predators, they have essentially no defense against a rat in the nest.

The impact of rats on puffin colonies has been demonstrated dramatically through eradication programs. On Handa, off the northwest coast of Scotland, puffin numbers increased rapidly in the five years after rats were removed. At Lundy, an island in the Bristol Channel, the puffin population went from just five birds to more than 200 breeding pairs following rat eradication.⁵ Manx shearwaters, which nest in similar burrows, showed equally dramatic recoveries at Ramsey and Lundy. These numbers make the case plainly: for burrow-nesting seabirds, removing introduced ground predators can be the single most effective conservation action available.

American mink, introduced to parts of Europe for fur farming and subsequently escaped into the wild, are another ground predator that affects puffin colonies. Mink are excellent swimmers and can reach offshore islands that might otherwise be safe havens. Arctic foxes pose a natural threat at Icelandic colonies, where they have coexisted with puffins for thousands of years. The relationship between foxes and puffins in Iceland is more balanced than the relationship between rats and puffins elsewhere, partly because Icelandic puffin colonies are enormous and can absorb some predation, and partly because foxes and puffins have had evolutionary time to reach a rough equilibrium.

Why Fledglings Face the Greatest Danger

A puffin chick’s single most perilous moment comes when it leaves the burrow for the first time. Puffin fledglings, often called pufflings, typically depart at night to reduce their exposure to predators. But not all fledglings manage this equally well, and the difference between a successful and a disastrous departure can come down to body size and the terrain between the burrow and the ocean.

Research comparing fledging behavior in the Faroe Islands and northern Norway found that fledglings which left on the wing reached the sea about an hour earlier and could fly beyond inshore waters before daybreak, avoiding the zone where gulls hunt most actively. Larger fledglings were more likely to manage this. Smaller fledglings that left on foot, by contrast, lost considerable time and energy struggling through dense vegetation, boulders, and the tidal zone. They were still near shore at dawn, squarely in the area that predators patrol most intensively.⁶ On islands with large gull populations, such as Bleiksøy in Norway, this predatory pressure appears to significantly influence the timing and success rate of fledging.

The contrast with Nólsoy in the Faroe Islands is telling: large predatory gulls are nearly absent there, and fledgling departure timing is less tightly constrained. Where gulls are abundant, natural selection favors chicks that grow fast enough to fly on their first attempt and leave under cover of darkness. Where gulls are absent, the pressure relaxes, and a wider range of departure strategies can succeed.

How Artificial Light Makes Things Worse

The fledgling’s dependence on darkness for a safe departure creates a modern vulnerability that puffin ancestors never had to contend with. Coastal lighting from towns, ports, and industrial facilities can disorient pufflings during their maiden flights. Researchers studying this on Gull Island tested the effect directly by flooding a 50-meter stretch of beach near a puffin colony with bright white LED light over eleven nights. Of 136 pufflings tracked with night-vision binoculars, many flew along the shoreline or headed back inland rather than out to sea, and multiple birds became stranded and needed rescuing. On a nearby unlit beach during the same period, only two pufflings passed by at all.⁷

A stranded puffling is a dead puffling without human intervention. Grounded birds cannot take off again from flat terrain and become easy prey for gulls, cats, or any other opportunistic predator once dawn arrives. In Iceland and Newfoundland, organized puffling rescue efforts have become a community tradition in coastal towns near large colonies. Volunteers patrol streets and beaches at night during the fledging season, collecting disoriented birds and releasing them at the shoreline. These efforts save thousands of birds annually, but they are treating a symptom. Reducing or shielding coastal lighting near colonies would address the underlying problem.

How Puffins Protect Themselves

Despite being slow in the air and defenseless in a one-on-one encounter with a gull or eagle, puffins are not passive victims. Their primary defense is collective. Tufted puffins approaching their breeding colony in the presence of bald eagles synchronize their arrivals into tight waves, using the safety-in-numbers principle that a predator can only catch one bird at a time. When eagles are present, puffins reduce their overall activity rate and shift toward lower-risk approach routes, staying over water where they can dive to escape an aerial attack rather than committing to a landing on exposed cliff faces.⁸

The degree of synchrony tracks the level of danger. When no predators are around, puffins arrive in loose, somewhat clustered waves. When eagles have been seen recently but are not currently visible, clustering tightens. When eagles are actively present, the synchrony is strongest, with birds arriving in tight pulses separated by long quiet gaps.⁸ This behavioral flexibility is impressive for a bird that looks, frankly, like it was designed by a committee. The clown-like appearance conceals a species that is paying close attention to its surroundings and adjusting its behavior in real time.

Burrow nesting itself is a defense strategy. By breeding underground, puffins remove their eggs and chicks from the reach of most avian predators. A great black-backed gull can kill an adult puffin, but it cannot fit into a puffin burrow to take an egg. This is why ground-dwelling mammals like rats and mink are so destructive: they exploit the one vulnerability in an otherwise effective defensive arrangement.

Predation in the Water

Puffins spend most of their lives at sea, coming to land only to breed, and the ocean carries its own risks. Large predatory fish, marine mammals, and diving seabirds can all take puffins in the water. Specific documentation of underwater predation on puffins is sparse compared to what we know about land-based and aerial threats, partly because it is extremely difficult to observe. Puffins are agile underwater swimmers, using their wings to “fly” through the water at considerable speed, which gives them a better chance of escaping aquatic predators than they have against aerial ones. But a puffin resting on the surface between dives is exposed, and predatory fish or seals can strike from below.

Young puffins that have just fledged and reached the sea face a particularly uncertain period. They arrive on the ocean alone, without parental guidance, and must teach themselves to dive and catch fish. During this learning period, they are smaller, less experienced, and more likely to rest on the surface for extended periods, all of which increase their exposure to marine predators. This stage of life is poorly studied because tracking small juvenile seabirds in the open ocean is logistically challenging, but it is widely assumed to be one of the highest-mortality windows in a puffin’s life.

When Human History Was the Biggest Predator

Before conservation became a priority, humans were the puffin’s most destructive predator by far. Atlantic puffins across North America were heavily hunted for eggs, feathers, and food, and many populations suffered drastic declines as a result.⁹ In Iceland, puffin hunting has been a cultural tradition for centuries, with tens of thousands of birds harvested annually using long-handled nets called “háfur.” Icelandic colonies were historically so large that this level of harvest was sustainable, though declining puffin numbers in recent decades have led to voluntary and regulatory restrictions on hunting in some areas.

The feather trade of the nineteenth century was particularly devastating. Puffin skins and feathers were used in women’s hats and fashion accessories, and industrial-scale collection wiped out or severely reduced colonies along the coast of Maine and the Canadian Maritimes. Major conservation initiatives were later undertaken to recover these populations, including the famous Project Puffin led by Stephen Kress beginning in the 1970s, which pioneered the technique of using decoys and recorded calls to lure puffins back to islands where they had been extirpated. That work succeeded in reestablishing breeding colonies on several Maine islands, but the populations remain small and fragile compared to their historical size.

The Predator Balance and Colony Size

One pattern runs through nearly all of the research on puffin predation: colony size matters enormously. A large, healthy colony can absorb predation from gulls, skuas, and even foxes without declining. The predators take some individuals, but the sheer number of breeding pairs means the losses are a small fraction of the population. A small colony, by contrast, can be trapped in a predator pit where losses outpace reproduction and the population spirals downward.

The Burhou situation illustrates this clearly. Great black-backed gull numbers had not increased, but once the puffin population shrank, the same number of gulls exerted disproportionate pressure on fewer birds, and the combination of direct predation and reduced recruitment caused by high densities of nesting gulls prevented recovery.² Conservation managers dealing with struggling puffin colonies need to think about this interaction. Protecting puffins is not always about reducing predator numbers; sometimes it is about boosting puffin numbers past the threshold where predation stops being the limiting factor. Removing rats, managing gull access to nesting areas, and restoring habitat can all help push a colony past that critical tipping point where its own size becomes its best defense.