Penguins can’t fly, yet many species make some of the longest seasonal journeys of any seabird, and they do it entirely by swimming. They lost flight more than 60 million years ago and evolved a body built for the sea.1Bark & Whiskers. The Bird That Hasn’t Flown for Over 60 Million Years Their winter migration is mostly an underwater trip far from land, which is why it went unseen until birds carried small trackers.
What Penguin Migration Looks Like
Penguins need land for only two things: breeding and replacing their feathers once a year. So in the months after the annual moult, many species head out to sea and stay there until the next breeding season. Macaroni penguins stay out for about six months.2PubMed Central. Where do penguins go during the inter-breeding period? Using geolocation to track the winter dispersion of the macaroni penguin Fiordland and Snares penguins in New Zealand stay out for about four and a half months.3PubMed Central. The role of allochrony in influencing interspecific differences in foraging distribution during the non-breeding season between two congeneric crested penguin species
The reason they can’t just linger near the colony comes down to the chicks. While parents are raising young, they must return to feed them, so foraging trips are short and radiate out from the nest. Once chicks fledge, that constraint disappears and adults can go wherever prey is richest. First, though, they need a complete new set of waterproof feathers. They build up fat beforehand and then fast on land while the moult runs its course. Only when the new plumage is in place can a bird safely go back to sea for months.
Not every penguin travels in one direction. Many crested penguins don’t follow a single route; birds fan out from the colony in many directions.4PubMed Central. Love thy neighbour or opposites attract? Patterns of spatial segregation and association among crested penguin populations during winter Chinstrap penguins vary so much from bird to bird that they show no shared winter hotspot.5PubMed Central. Individual variation in migratory movements of chinstrap penguins leads to widespread occupancy of ice-free winter habitats over the continental shelf and deep ocean basins of the Southern Ocean Some species, like the Magellanic penguin, do follow one clear corridor along a coast.6Biological Conservation. Conservation of migratory Magellanic penguins requires marine zoning
This differs from the way flying birds migrate. A swallow or a goose commutes between two fixed homes, stopping to rest and often fasting between stopovers. A penguin swims the whole way, so even a 2,000 km trip takes weeks rather than days, and it feeds as it goes. Its only fixed point is the colony it returns to.
Antarctic Penguins That Follow the Sea Ice
Adélie penguins in the southern Ross Sea live at the far southern edge of their range.7PubMed. Going with the floe: Sea-ice movement affects distance and destination during Adélie penguin winter movements That is why they make the longest known winter migration for the species, about 12,000 km.8PubMed. Going with the floe: Sea-ice movement affects distance and destination during Adélie penguin winter movements In East Antarctica, Adélies head west after breeding, move north from May to August as the sea ice edge grows, and then turn back toward the colony.9Marine Ecology Progress Series. Migratory movements and winter diving activity of Adélie penguins in East Antarctica The sea ice edge is the line where floating ice meets open water. Their path tracks the moving ice, which currents and wind push westward.10Marine Ecology Progress Series. Migratory movements and winter diving activity of Adélie penguins in East Antarctica In the Ross Sea, nearly all their winter locations fell outside a proposed marine protected area.11Marine Policy. Adélie penguins’ extensive seasonal migration supports dynamic Marine Protected Area planning in Antarctica
The edge matters because it offers both things a penguin needs. A bird can dive into open water for prey, then climb out onto the ice to rest. The ice gives a safer platform away from leopard seals and orcas, though some risk remains near the edge. Krill that feed on algae growing under the ice tend to be richer there. In high-latitude winter the edge also holds the little daylight available, so birds near it can hunt by sight for longer.
Emperors take the opposite approach. They breed in the middle of the Antarctic winter, so their colonies stay within about half a kilometre of the same spot through winter, as seen from satellites.12PubMed Central. Year-round movement of emperor penguin colonies observed from space They feed in small, short-lived cracks and openings in the ice and spend about 23% of their time there.13Geophysical Research Letters. Dynamic Fine‐Scale Sea Icescape Shapes Adult Emperor Penguin Foraging Habitat in East Antarctica Changes in sea ice cover therefore affect where these birds can feed.14Sea Ice. Sea ice: A seabird world of its own
Sub-Antarctic Penguins That Chase Ocean Fronts
Macaroni penguins from Kerguelen head east and spread over more than 3 million square km.15PubMed Central. Where do penguins go during the inter-breeding period? Using geolocation to track the winter dispersion of the macaroni penguin Even so, they spend most of their time in a narrow band of the central Indian Ocean in the Polar Front zone.16PubMed Central. Where do penguins go during the inter-breeding period? Using geolocation to track the winter dispersion of the macaroni penguin Where macaroni and southern rockhopper penguins breed side by side, macaronis winter farther south in colder water.17PubMed Central. A Space Oddity: Geographic and Specific Modulation of Migration in Eudyptes Penguins
A front is a boundary where warm and cold water masses meet. Where different water masses mix, nutrients can be brought toward the sunlit surface. Those nutrients feed tiny drifting plants, which feed small animals such as krill and small fish. Eddies, spinning patches of water tens to hundreds of km across, trap prey as well. A predator finds food packed into a smaller area than in open water and spends less energy searching, so a front is a destination a penguin can aim for, not just a place it passes through.
Macaroni penguins aim for the sub-Antarctic Front and feed around swirling eddies.18PubMed Central. Influence of oceanographic structures on foraging strategies: Macaroni penguins at Crozet Islands King penguins ride fast currents to reach feeding areas and then slow down to forage inside the eddies.19PubMed Central. Movements of foraging king penguins through marine mesoscale eddies
A trip often falls into stages. On the way out, birds travel fast with the current. The middle stage is spent feeding slowly in rich water, and this is where most of their time around eddies falls.20PubMed Central. Influence of oceanographic structures on foraging strategies: Macaroni penguins at Crozet Islands Then they swim back toward the colony.
Warmer-Water Penguins From Coastal Travellers to Homebodies
Magellanic penguins migrate north along South America, even birds from Pacific-side colonies.21Ocean and Coastal Management. Movements of satellite tracked Magellanic penguins (Spheniscus magellanicus) in a wintering area in southern Brazil They reach the waters of northern Argentina, Uruguay and southern Brazil, on average about 2,000 km from home.22Biological Conservation. Conservation of migratory Magellanic penguins requires marine zoning They stay within about 250 km of shore along the way.23Biological Conservation. Conservation of migratory Magellanic penguins requires marine zoning Penguins washing up on Brazilian beaches in winter are often Magellanic migrants.
Such a bird is not necessarily lost. Many arrive tired and thin after weeks of swimming, which is why some come ashore. One standing quietly on the sand isn’t necessarily sick, but it may need help if it is clearly weak or injured. If you see one, contact local wildlife rescue, and don’t feed or handle it.
Some penguins hardly travel at all. Galápagos penguins raising chicks feed on average only about 5 km from the nest, mostly within 1 km of shore.24Inter-Research Science Publisher (Endangered Species Research). Space use by foraging Galápagos penguins during chick rearing The cool, food-rich water around the islands is close by, so long trips aren’t needed.
Distance reflects local food supply more than species habit. Penguins move when food near the colony runs short, and where food stays nearby all year, staying put saves energy. That also explains why Gentoo penguins in the Falklands vary from bird to bird, with trips ranging from 64 to 600 km.25Ibis. Non‐breeding movements of Gentoo Penguins at the Falkland Islands
How Penguins Find Their Way and Swim So Far
Different cues seem to matter at different distances. Earth’s magnetic field probably helps penguins only on long migrations, because over shorter distances the field barely changes.26West Coast Penguin Trust. How do penguins find their way home? Far from home a penguin has little to see, so a broad cue like the field can help it hold a general direction. Closer to home, penguins seem to rely on what they see.27West Coast Penguin Trust. How do penguins find their way home? Tawaki penguins appear to follow a bulge in the sea surface above an underwater ridge on their way back to New Zealand.28West Coast Penguin Trust. How do penguins find their way home?
On the final approach, sound can take over. King penguin chicks find their way home by the sound of the colony, and changing the magnetic field didn’t confuse them.29PubMed. The invisible cues that guide king penguin chicks home: use of magnetic and acoustic cues during orientation and short-range navigation Researchers describe this layering as likely, not proven.
Efficient swimming makes the distances possible. Little penguins travel just below the surface, which can cut wave drag by 75 to 100%.30PubMed Central. Optimization of swim depth across diverse taxa during horizontal travel Swimming right at the surface makes waves that waste energy, while staying slightly under avoids this and still allows a quick breath. Adélie penguins cruise at about 2.2 metres per second, roughly 8 km an hour.31PubMed. Underwater swimming at low energetic cost by pygoscelid penguins Steady travel at that pace covers hundreds of km a week.
How Scientists Track Penguins at Sea
Each tool answers a different question. Leg bands recovered far away first showed Magellanic penguins’ long trips,32Biological Conservation. Conservation of migratory Magellanic penguins requires marine zoning but a band says only where a bird started and where it was found, with nothing about the path in between. Bands also need someone to find the bird again. Satellite tags revealed the coastal corridor,33Biological Conservation. Conservation of migratory Magellanic penguins requires marine zoning showing a path in detail, though they are heavy and can’t stay on a bird for long.
A geolocator is a light tag that estimates position from day length and sunrise times. It is the only practical way to follow small seabirds for months,34Endangered Species Research. Quantitative method to estimate species habitat use from light-based geolocation data and it can last a year. Its positions are rough, though.35Endangered Species Research. Quantitative method to estimate species habitat use from light-based geolocation data Researchers recover light tags when birds return to the colony.
Tracking has also shown what young penguins do. Young king penguins cover 3,317 to 13,259 km and reach up to 4,655 km from home, farther than adults.36PubMed Central. Exploration during early life: distribution, habitat and orientation preferences in juvenile king penguins They explore widely before settling into adult routes.
How Climate Change and Fishing Affect Penguin Journeys
As Ross Sea ice shrinks, Adélie migrations are expected to change.37PubMed. Responding to climate change: Adélie Penguins confront astronomical and ocean boundaries Crested penguins’ winter habitat is likely to shift toward the pole, and less warming means less habitat loss.38PubMed Central. Potential for redistribution of post‐moult habitat for Eudyptes penguins in the Southern Ocean under future climate conditions
Fisheries share their waters too. Wintering Magellanic penguins overlap bottom trawl fisheries throughout their range.39PubMed Central. Sex-specific spatial use of the winter foraging areas by Magellanic penguins and assessment of potential conflicts with fisheries during winter dispersal Breeding Magellanics overlapped fishing fleets in 1–26% of their range in 2014–2016, down from 12–61% in 2005–2007.40Marine Ecology Progress Series. Spatial use of multiple jurisdictions by Magellanic penguins and assessment of potential conflicts in the face of changing trawl fisheries scenarios Yellow-eyed penguin feeding areas overlap gillnet fisheries in New Zealand.41Biological Conservation. Risks, resources, and refugia: Spatial overlap between yellow-eyed penguin foraging distribution and prey, commercial fisheries, and marine protected areas
Protected areas drawn around colonies miss most migration routes.42Marine Policy. Adélie penguins’ extensive seasonal migration supports dynamic Marine Protected Area planning in Antarctica A zone around a colony covers the breeding season well, but penguins leave for months and may travel hundreds or thousands of km. Winter positions for Ross Sea Adélies largely fell outside the proposed area. Routes can also cross the waters of several countries, so no single government can protect the whole journey. Moving zones that track the birds’ seasonal route have been proposed.