What Are the Main Predators of Puffins?

Puffins face threats from the air, the ground, and the sea. Their most dangerous predators are large seabirds, especially great skuas and great black-backed gulls, which hunt adult puffins and chicks at breeding colonies. But the full cast of predators extends to raptors, gulls that steal food rather than kill outright, ground-dwelling mammals, and even underwater hunters. Which predators matter most depends on where in the world a puffin breeds and whether introduced species have reached its nesting island.

Great Skuas, the Specialist Puffin Hunters

At many North Atlantic puffin colonies, the great skua is the single most significant predator of adult puffins. These powerful seabirds are roughly twice the weight of a puffin and hunt them with remarkable persistence. On Fair Isle, between Scotland and Orkney, researchers found that remains of puffins killed by great skuas and direct observations of skua predation were extensive over nearly three decades, with more than 50 incidental observations of predation recorded per year. During that same period, evidence of predation by any other species on the island was found less than once a year.¹

Great skuas use two main hunting techniques against puffins. They chase them in the air, using their size advantage and powerful flight to wear down a puffin returning to the colony, and they ambush puffins on the ground near burrow entrances. A puffin carrying a bill-load of fish back to its chick is a particularly attractive target because it is weighed down and reluctant to drop its catch. Once caught, the puffin is killed with repeated blows and typically consumed whole or in large pieces.

What makes great skuas especially impactful is that they kill breeding adults, not just eggs or chicks. Since puffins are long-lived birds that typically rear just one chick per year, losing breeding adults removes future reproductive output for many seasons. A colony can absorb some egg or chick losses far more easily than the loss of experienced breeders.

Great Black-backed Gulls

The great black-backed gull is the largest gull in the world and one of the most formidable predators puffins face. These gulls are generalists. They eat fish, invertebrates, and smaller seabirds, adjusting their diet to whatever is most available. At colonies where great black-backed gull numbers have grown, their impact on puffins can become severe.

On the Isle of May in Scotland, breeding numbers of great black-backed gulls have been increasing since the 1980s, and researchers have documented rising predation on the Atlantic puffin colony breeding alongside them.² The gulls patrol puffin colonies during the breeding season and pick off adults arriving with fish, chicks that wander near burrow entrances, and occasionally adults resting on the surface near the colony. A great black-backed gull will typically swallow a puffin whole, sometimes after drowning it in the sea.

Unlike great skuas, which are relatively specialized seabird predators, great black-backed gulls shift between food sources seasonally. This means puffin predation can spike during the breeding season when puffins are concentrated and visible on land, even if gulls eat mostly fish or refuse during the rest of the year. It also makes predation harder to predict, since gull diet depends on what else is available.

Herring Gulls and the Cost of Stolen Fish

Herring gulls are smaller than great black-backed gulls and rarely kill adult puffins, but they impose a different kind of cost: kleptoparasitism, meaning food theft. Herring gulls station themselves near puffin colonies and intercept adults carrying fish back to their chicks. A study at a colony found that herring gulls attacked about 8% of provisioning puffins that entered their immediate area, and when they did attack a puffin that had already landed, they succeeded in stealing some or all of the fish roughly a quarter of the time.³

A quarter success rate sounds modest, but the cumulative effect matters. Puffin parents often need to make many foraging trips per day to feed a growing chick, and every stolen load means an extra trip. If food is already scarce because of poor fish years, those extra trips burn energy the parent cannot spare. In bad years, kleptoparasitism can tip the balance between a chick that fledges successfully and one that starves in the burrow.

Herring gulls are not the only kleptoparasites puffins deal with. Arctic skuas (also called parasitic jaegers) are specialized food pirates that harass puffins in flight until they drop their fish. The dynamic is similar, but arctic skuas tend to be more persistent aerial chasers, while herring gulls rely on ambush near the colony.

Raptors at Puffin Colonies

In North America, Tufted Puffins breeding along the Pacific coast face predators that Atlantic Puffins in Europe rarely encounter. Bald eagles and peregrine falcons nest near Tufted Puffin colonies and pose a real threat. At one studied colony, a pair of bald eagles nested at one end of the slope and peregrine falcons nested in the central part of the same slope where puffins breed.⁴

A bald eagle is large enough to kill an adult puffin outright, though it tends to be an opportunistic predator at seabird colonies rather than a specialist. Peregrine falcons are fast enough to catch puffins in flight, and their presence above a colony can shut down puffin activity for extended periods as birds refuse to land or take off while a falcon is visible. White-tailed eagles fill a similar niche in parts of northern Europe, though they are less commonly studied in the context of puffin predation specifically.

The raptor threat differs from gull or skua predation in an important way. Eagles and falcons tend to pick off individual birds rather than systematically working through a colony, so their per-bird kill rate is lower. But their effect on colony behavior can be dramatic, as described below.

Mammals on the Ground

Puffins nest in burrows, which makes them vulnerable to any ground-dwelling predator that can reach their nesting islands. In Iceland and parts of the Arctic, Arctic foxes are a natural predator of puffins and can dig into burrows to take eggs, chicks, and sometimes incubating adults. Foxes are especially dangerous because a single fox in a puffin colony can destroy dozens of nests in a night, far more than it can eat, a behavior sometimes called surplus killing.

In North America, American mink are a significant threat at some puffin colonies. Mink are excellent swimmers and can reach offshore islands, where they prey on seabird eggs and chicks with devastating efficiency. A mink establishing itself on a small puffin island can crash breeding success in a single season.

Introduced mammals are often the most destructive predators puffins face. Rats brought to islands by ships eat puffin eggs and small chicks and can persist in large numbers once established. Feral cats, similarly, have been documented killing puffins at some colonies. On Fair Isle, the long-term study that found great skuas to be the dominant predator also noted that domestic and feral cats occasionally killed puffins, though far less frequently.¹ The difference with introduced mammals is not just the direct killing. Puffins evolved on islands largely free of ground predators, so they have few defenses against a determined mammal entering their burrow. A puffin incubating an egg underground is essentially trapped.

Predators Beneath the Waves

Puffins spend most of their lives at sea, and the ocean is not a safe haven. Large predatory fish and marine mammals occasionally take puffins. In the North Atlantic, grey seals and harbour seals have been observed catching puffins on the water surface or just beneath it. The encounters are opportunistic rather than systematic, but they do happen, especially near colonies where puffins raft on the sea in large groups before coming ashore.

Underwater, puffins face potential threats from large fish. Puffins dive to depths of 60 meters or more to catch sand eels and other small prey, and at those depths they enter the range of fish like cod and pollack that are large enough to eat a diving puffin. Documentation of underwater predation is inherently difficult, so the frequency is poorly understood compared to predation at breeding colonies. What is clear is that puffin mortality at sea, from predation and other causes combined, is substantial, particularly during the winter months when birds are dispersed across open ocean far from any colony.

How Puffins Respond to Predators

Puffins are not passive targets. They have evolved several behavioral strategies to reduce predation risk, and these strategies differ depending on what kind of predator is nearby.

One of the best-documented responses involves the timing of colony visits. Tufted Puffins at a colony with resident bald eagles adjusted their arrival and departure patterns based on whether eagles were present. When eagles were around, puffins bunched their arrivals more tightly, increasing the synchrony of their flights to and from the colony. The clustering effect increased as the danger level increased: it was minimal when no predators were present, higher when eagles had been seen recently but were not currently visible, and highest when eagles were actively present.⁴ Arriving in tight groups dilutes each individual’s risk, the same logic behind schooling fish or flocking starlings.

Puffin chicks use a different tactic. At many colonies, chicks leave their burrows for the sea at night, under the cover of darkness, to avoid the gulls that patrol during the day. Research on Atlantic Puffins in Norway and the Faroe Islands found that fledglings that departed on the wing reached the sea roughly an hour earlier and could fly beyond inshore waters before dawn, reducing their exposure to gull predation. At colonies where large gulls were numerous, this selective pressure appeared to have a significant effect on the timing of fledging itself.⁵ In other words, the gull threat shapes not just when chicks leave, but potentially the developmental schedule that determines when they are ready to leave.

Adult puffins at the colony also rely on their burrows as refuges. When a raptor appears overhead, puffins dive into their burrows or press flat against the ground rather than taking flight, since a fleeing puffin in the air is easier for a falcon to catch. Colony density itself provides some protection, too: in dense colonies, the sheer number of birds makes it harder for a predator to single out an individual, and arriving puffins can follow others already in flight to reduce their own exposure.

When Predator Removal Changes Everything

Because introduced predators can be so devastating to island-nesting seabirds, conservationists have invested heavily in predator-removal programs. Rat eradication on seabird islands has become a well-tested conservation tool, and dozens of islands worldwide have been cleared of rats with measurable recoveries in seabird breeding success. For puffins specifically, removing invasive mammals from nesting islands has allowed recolonization or population recovery in several cases.

The most famous puffin restoration project took place on Eastern Egg Rock in Maine, where Atlantic Puffins had been wiped out by a combination of hunting and predation. Between 1973 and 1986, over a thousand puffin chicks were translocated to the island and social-attraction techniques, such as puffin decoys and recorded calls, were used to lure returning birds to nest.⁶ The project succeeded, and the colony continues to breed today. Part of what made recovery possible was managing predators on and around the island, including gulls that would otherwise prey on the small restored population.

Managing native predators is more complicated than removing invasive ones. Great black-backed gulls and great skuas are native species with their own conservation value. On the Isle of May, where great black-backed gull predation on puffins has been increasing, conservationists face a genuine dilemma: the gulls are not “invasive” and have legitimate ecological roles, but their growing numbers threaten a puffin colony of international importance.² These situations require ongoing monitoring and sometimes selective management rather than the more straightforward eradication approach that works for rats.

Why Predation Pressure Varies So Much Between Colonies

One of the things that makes puffin predation complicated is how different it looks from one colony to the next. On Fair Isle, great skuas dominate. On the Isle of May, great black-backed gulls are the rising concern. In Iceland, Arctic foxes may be the primary terrestrial threat at some colonies while being absent from others. On Pacific islands, bald eagles and peregrine falcons create a predator landscape that European Atlantic Puffin colonies never encounter.

Geography explains much of this variation. Puffins breed on islands and coastal cliffs across a huge range, from Maine to Norway to Iceland to the Aleutian Islands. The predator community at each site depends on what other species live there, and island isolation matters enormously. A small offshore island with no mammalian predators is a fundamentally different environment from a large island connected to a mainland fox or mink population. Colony size also plays a role. Very large colonies, like those in Iceland that hold hundreds of thousands of pairs, can absorb predation losses that would cripple a colony of a few hundred pairs.

Climate change is reshuffling some of these dynamics. As ocean temperatures shift and fish populations move, puffins at some colonies are having worse breeding seasons because their usual prey is harder to find. A puffin that has to fly farther and work harder to feed its chick is more exposed to kleptoparasites and aerial predators during each trip. Meanwhile, some predator populations are expanding into new ranges or breeding more successfully in warmer conditions. The interaction between declining food and steady or increasing predation pressure is one of the less obvious ways that climate affects puffin populations, and it is not captured by looking at predator numbers alone.

The Distinction Between Predation and Population Decline

It is tempting to think that the way to help puffins is simply to remove their predators, but the relationship between predation and population health is not that straightforward. Predation is a natural part of the ecosystem puffins evolved in. Great skuas have been eating puffins for thousands of years, and puffin populations coexisted with them at enormous sizes. What turns normal predation into a conservation problem is usually something else going wrong at the same time.

When food is plentiful and breeding success is high, a puffin colony can sustain considerable predation without declining. The colony produces enough new breeders each year to replace the ones lost. Problems arise when food shortages reduce breeding output while predation remains the same or increases. Suddenly the colony is losing adults faster than it replaces them. On Fair Isle, researchers evaluating the decline of the puffin population found that predation by great skuas was one factor, but changes in food availability and broader demographic shifts were also at play.¹

The practical takeaway for conservation is that predator management alone rarely solves a puffin colony’s problems. It can buy time and reduce immediate losses, especially when the predator is an invasive species that should not be there in the first place. But for native predators, the more sustainable approach is usually ensuring that the broader ecosystem, particularly the fish stocks puffins depend on, remains healthy enough to support high breeding productivity. A well-fed puffin colony can live with its predators. A starving one cannot.