Seabirds off the Lisbon Coast
This guide was led by our team of ornithologists and marine biologists. If you’d like to see these species in the wild, check out our Birdwatching Tour in Lisbon!
Pelagic birdwatching takes place offshore, beyond the coastline, where ocean processes shape marine life in remarkable ways. Unlike coastal observation, it allows us to witness seabirds in their true environment, far from land and deeply connected to the dynamics of the Atlantic Ocean.
Seabirds are highly adapted to life at sea. Many species spend most of their lives over open water, returning to land only to breed. Their long wings allow efficient gliding over waves, specialised salt glands enable them to drink seawater, and their acute senses help them locate prey across vast distances.
Along the Lisbon coast, Atlantic currents, seasonal upwelling and the nutrient input from the Tagus Estuary create productive waters rich in fish. Where prey concentrates, predators follow. Observing seabirds offshore, therefore, becomes a way of understanding marine ecology in action.
Careful field observation helps reveal these connections, turning each sighting into an opportunity to read the ocean and better understand its balance.
Quick Facts
Number of species recorded
31 species were recorded, mostly during our birdwatching tours.
Most common species
Cory’s Shearwater, Northern Gannet, European Storm-petrel, Balearic Shearwater
Best time of year for observation
From September to May, when a variety of seabirds begin flying south from the Northern Hemisphere to lower latitudes, such as Lisbon.
Where they are most frequent
Open Sea. Portugal is in the middle of two great migration routes for birds: The North Atlantic Migration Route and the Mediterranean Migration Route.
Species Gallery
Cory’s Shearwater
Scientific name: Calonectris diomedea borealis
Habitat: Open Sea
When we see it: Summer, Breeding season
Probability: High
ID notes: Large body: brown above and white below; pink feet; thick yellow bill.
Northern Gannet
Scientific name: Morus bassanus
Habitat: Open Sea
When we see it: Wintering and transient migrant
Probability: High
ID notes: Heavy-bodied; long wings; pointed tail and bill; Adults are snow white with black wingtips and yellow heads; juveniles are sooty brown; subadults are intermediate, often appearing a patchwork of dark and light feathering.
European Storm-petrel
Scientific name: Hydrobates pelagicus
Habitat: Open Sea
When we see it: Transient migrant; from May to December
Probability: High
ID notes: Small body; black plumage; black bill; white rump and underwing band; square tail; fluttering flight pattern; Juveniles may show a narrow white bar on the upper wing.
Balearic Shearwater
Scientific name: Puffinus mauretanicus
Habitat: Coastal and Open Sea
When we see it: Summer visitor, transient migrant, and winter visitor
Probability: High
ID notes: Medium sized body; plumage transitions from dark brown to dirty white; dark upperparts and paler undersides; dark grey bill; pink legs; feet black.
Common Tern
Scientific name: Sterna hirundo
Habitat: Coastal
When we see it: Reproductive summer and migratory passage
Probability: High
ID notes: Pale grey body with a black cap; long, narrow and angular wings; pointed wingtips; straight and slender bill; forked tail; short legs; Breeding birds have a fully black cap that extends to the back of the neck and a grey belly, range bill tipped in black and orange legs. Nonbreeding birds have a white forehead, a partial black cap, black legs and a black bill.
Little Tern
Scientific name: Sternula albifrons
Habitat: Coastal
When we see it: Reproductive summer and migratory passage
Probability: Medium
ID notes: Small body; silvery grey above and white below; black cap and black strip covering each eye; white patch on the forehead; yellow legs; non-breeding adults have a black bill, dark legs, and a more extensive white forehead; Breeding adults have orange legs, a yellow beak with black tip and a distinctive white forehead and black cap.
Common Murre
Scientific name: Uria aalge
Habitat: Open Sea
When we see it: Breeding and wintering
Probability: Medium
ID notes: Large and heavy body; long and pointed bill; short tail; slender and pointed wings; Breeding adults have blackish head, face, upperparts and clean white below. Nonbreeding adults have a pale throat and face with a dark line behind the eye. Some Atlantic adults in breeding plumage have a white eyeing with a white line extending behind it.
Great Skua
Scientific name: Catharacta skua
Habitat: Open Sea
When we see it: Transient migrant and winter visitor
Probability: High
ID notes: Gull-like appearance; Dark brown plumage with golden-brown streaks; adults with darker cap; juveniles are warmer blown and without streaks below; White patches on upper and underwings; thick, dark and hooked bill; short tail; aggressive behaviour towards other seabird species.
Great Cormorant
Scientific name: Phalacrocorax carbo
Habitat: Coastal
When we see it: Wintering and resident; November to March
Probability: High
ID notes: Big dimension; long and thick neck; blocky head; heavy hooked bill; short legs; long tail; broad wings; Adults are black with white throat and yellow skin around the bill; breeding adults have a square patch of white on the thigh and white neck feathers; Juveniles are brownish with a white throat and belly, with some brownish streaking at the edges.
European Shag
Scientific name: Phalacrocorax aristotelis
Habitat: Coastal
When we see it: Resident and winter visitor
Probability: High
ID notes: Medium-sized; distinct crest and yellow facial skin during breeding; Long-bodied; thin neck; small head; steep forehead; Adult plumage is glossy black with a distinct green sheen; non-breeding adults are black brown with white feathering on the throat; emerald green eyes.
Great Shearwater
Scientific name: Ardenna gravis
Habitat: Open Sea
When we see it: Transient migrant; August to November
Probability: High
ID notes: Long, straight, medium-width wings; head and tail project about equally from the body. Thin and dark Bill; Adults have a dark cap that contrasts strongly with a white neck collar and a white band at the base of the tail; wings with dark edges.
Sooty Shearwater
Scientific name: Ardenna grisea
Habitat: Open Sea
When we see it: Transient migrant; August to November
Probability: Medium
ID notes: Gull-sized; narrower wings; small and rounded head; long, slender and strongly hooked bill, with tubelike nostrils set on top of the bill; Short tail; Dark brown; Bill, eye, and feet are dark.
Arctic Jaeger
Scientific name: Stercorarius parasiticus
Habitat: Open Sea
When we see it: Transient migrant and winter visitor
Probability: High
ID notes: Medium-sized; slender body; White underparts; dark grey brown back (Three primary color variations: Light, dark and intermediate morph); black cap with yellow/white neck sides; white patch at the base of wing feathers; breeding adults feature two central tail feathers that project beyond the rest of the tail, ending in sharp points; black, slightly hooked and slender bill; black webbed feet.
Common Scoter
Scientific name: Melanitta nigra
Habitat: Coastal
When we see it: Transient migrant and winter visitor
Probability: Medium
ID notes: Medium-sized duck; Males are black with a bulbous base to their bill, with a yellow-orange patch; Dark eyes; rounded head profile; Females are predominantly dark brown with paler cheeks and throat; Juveniles resemble females but with mottled plumage.
Yellow-legged Gull
Scientific name: Larus michahellis
Habitat: Coastal and Open Sea
When we see it: Resident
Probability: High
ID notes: Large body; bright yellow legs; adult grey back; white head; Yellow beak with a large red spot; Extensive black on the wingtips with white spots; juveniles have brown plumage with a black bill and pinkish-grey legs.
Lesser Black-Backed Gull
Scientific name: Larus fuscus
Habitat: Coastal
When we see it: Wintering, Transient migrant, and breeding.
Probability: High
ID notes: Medium/large body; long and pointed wings; larger head; thick bill; breeding adults plumage is white below, slate gray above, with white head, black wingtips, yellow eye, bright yellow legs, and yellow bill with red spot on lower mandible; nonbreeding plumage is similar but the head and neck are spotted brown; Juvenile is brown above, paler with gray/brown mottling below and black tail band.
Common Black-headed Gull
Scientific name: Chroicocephalus ridibundus
Habitat: Coastal
When we see it: Wintering, Transient migrant, and breeding.
Probability: High
ID notes: Medium-sized body; plumages have a big white blaze on the leading edge of the wing; Breeding adult has a dark brown (not black) hood, red bill and legs; non-breeding and immature have dark ear spot on white head, dark tip to red bill; Juvenile has mottled brownish back, which moults to pale grey by winter.
Sabine’s Gull
Scientific name: Xema sabini
Habitat: Open Sea
When we see it: Transient migrant.
Probability: Medium
ID notes: Small body; small head; slender and straight bill; long and pointed wings; forked tail; Breeding adults are white with a dark head and a three-toned wing pattern; In flight the upper wings are gray with a black triangle in the outer primaries and a white triangle along the trailing edge; red eye ring and a black bill with yellow tip; Nonbreeding adults have white speckles on the head and a dusky eye ring; Juveniles are brown above with pale feather edges, have an all-black bill and a black tip to the tail.
Manx Shearwater
Scientific name: Puffinus puffinus
Habitat: Ocean
When we see it: Transient migrant, from August to October.
Probability: Low
ID notes: Plumage with jet-black upperparts and white underparts; black ``cap`` on the head extends below the eye; subtle white crescent curling up behind the dark cheek; Underwing Pattern mostly white with dark borders and dark tips on the primary feathers; long, straight and slender bill with hooked tip and visible ``tube-shaped`` nostrils on the upper mandible.
Atlantic Puffin
Scientific name: Fratercula arctica
Habitat: Open Sea
When we see it: Transient migrant and winter visitor.
Probability: Medium
ID notes: Small body; short neck; big head; large triangular bill; short and straight wings; black above and white below; Breeding birds have a gaudy black, orange, and yellow bill and the face is gray/white; nonbreeding season the face turns darker gray, and the bill sheds its yellow highlights and shrinks slightly; Juveniles have all-dark bills.
Biologists’ Notes
Observation Success: It is important to conduct birdwatching activities with experts. We not only provide the necessary resources but also guarantee knowledgeable and safe supervision. Field guides provide detailed descriptions and illustrations, giving you the basics to identify birds by their appearance and location. But we also learn from you and from surprising observations. Because it is a wildlife activity, we cannot guarantee sightings. We can guarantee a good time in the middle of nature. Birdwatching requires patience and keen observation. Take time, be calm, and let the birds come around. Use binoculars to get a closer look at their details.
Law Protection: Portugal is a member of the European Union and is subject to the Birds Directive (2009/147/EC) and the Habitats Directive (92/43/EEC), which establish frameworks for the protection of species and habitats, including marine habitats and Natura 2000 areas.
How We Identify Them
Seabird identification at sea is a bit like solving a moving puzzle. Rarely do we see a bird perfectly framed and still. Instead, we observe silhouettes against the horizon, wingbeats over waves, or a distant shape gliding low above the water. Our approach is simple: gather as many field marks as possible and combine them into a best-fit identification.
We focus on structure first, because shape is often more reliable than colour at sea. Plumage patterns, flight style, behaviour and association with other species also provide important clues.
Note: Identification is not always possible. Light conditions, distance and sea state can limit what we see.
Science Deep‑Dive on the ecology of the group in the region of Lisbon
We know that the presence or passage along the Lisbon coast depends on the availability of food provided by our waters. The richness of the marine environment and ecosystem attracts numerous species. Areas of high productivity resulting from oceanographic phenomena such as upwellings, ocean currents, or river mouths are rich in nutrients, and trophic chains are enhanced. We have seabirds in Lisbon due to currents, prey diversity, and the Tagus Estuary, a crucial habitat that provides abundant food. The proximity of the Tagus River contributes to nutrient influx and the development of the ecosystem, which provides prey for seabirds.
Feeding and hunting strategies
In many food chains, seabirds can be found as predators or opportunists.
Seabirds feed on a wide range of marine organisms, from zooplankton to fish and cephalopods. The type of prey influences the foraging behaviour: small pelagic fish normally concentrate in schools and attract flocks of surface feeders (such as gulls and petrels) and plunge diver feeders (such as gannets, shearwaters and terns), whereas some other preys like squid, are caught by more solitary feeders. Fish shoals (herrings, sardines, mackrel, capelin, needlefish) are the main food source, and seabirds can normally be seen close to dolphins and whales while feeding.
Seabirds have diverse feeding strategies, primarily categorised as surface feeding (dipping, skimming, pattering), plunge-diving (from height or pursuit diving underwater), aerial pursuit, scavenging, and kleptoparasitism (stealing food). During our tours, we can observe feeding frenzies among seabirds and dolphins. We often see gannets diving from great heights to hunt, shearwaters and gulls frantically collecting prey remains or easily caught food on the surface, and even intense, noisy chases between species, notably skuas and gulls.
Ecological role
Seabirds are marine predators that occupy the upper trophic level in marine food chains. They are good indicators of the health of marine ecosystems and play a key role in them. Seabirds can contribute to shaping coastal ecological processes that directly influence trophic status, environmental contamination, biodiversity, and food chains through trophic and non-trophic processes.
Through seabirds’ feces, the amount of organic matter is increased both in the soil of breeding colonies and in relatively closed marine areas such as bays and estuaries. This participation in nutrient cycles is vital, since some elements, such as phosphorus and nitrogen, are recycled back into ecosystems.
Reproduction and life cycle
Seabird reproduction involves long lifespans, strong pair bonds (lifelong monogamy), colonial nesting, a breeding life cycle, long incubation periods, extensive foraging at sea, and parents sharing duties and raising young that take years to mature and can survive on their own. Their life stages include egg, hatchling, nestling, fledgling, juvenile, and adult, often with distinct wintering and breeding seasons.
In general, the lifespan of seabirds is longer than that of birds that live on land. Seabirds are renowned for their long lifespans, with many species living 30 to 50 years in the wild.
Behaviours that can be observed
Seabird behaviours are about efficient marine survival, including long-distance foraging flights, forming large land-based breeding colonies, and complex mating rituals (such as dances, displays, and fish-giving). They also exhibit diverse feeding strategies. Their life strategy involves high parental investment, long lifespans, late maturity, and strong pair bonds, with adaptations such as excellent olfaction and vision for finding food.
Migratory Pattern
Seabirds exhibit both migratory and sedentary behaviour. Their movements range from a daily short distance from nesting to feeding sites to seasonal intercontinental migrations for breeding, which involve ocean crossings.
Seabirds in the northern hemisphere go to winter south of their breeding colonies, where the weather is more hospitable, and there is a greater availability of food. During the entire non-breeding period, individuals of some species spend many months away from land and can be more solitary. The winter period is spent foraging for food and building reserves for the demands of the next breeding season. When back to their breeding ground, thousands will cram themselves onto cliff faces or wedge themselves into wave-worn rocks to nest.
Threats and conservation in the Lisbon region
Invasive alien species/Pollution/ Bycatch /Overfishing/ Habitat destruction/ Severe Weather
Seabirds are one of the most threatened groups of birds, with 31% of species globally threatened and nearly half experiencing population declines. They suffer a combination of marine and terrestrial pressures that often act cumulatively.
Some of the threats faced are invasive alien species when there is an introduction of an specie on a breeding area, when the animal is more vulnerable to being more focused on reproduction; Bycatch with incidental mortality in fisheries; overfishing affecting their feeding; hunting; climate change or severe weather; disturbance; destruction of habitats with chemicals, logging and wood harvesting. These are ongoing threats affecting most seabird species, with more than a fifth of all species.
What helps – simple and educational actions
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Fisheries management to reduce bycatch
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Regulation of human activities to protect nesting and feeding habitats.
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Support and contribute to seabird conservation and rehabilitation institutions
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Contact the authorities (SEPNA) or SPEA if you find seabirds in danger.
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Creation and management of MPAs to protect critical habitats.
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Environmental education at schools
Our Boat Tours
Our Boat Tours were carefully designed to offer the best nature and cultural experiences in the city.
Birdwatching Boat Tour
Dolphin Watching Boat Tour
Frequent Questions about Seabirds
What is the smallest seabird?
Storm-petrels are the smallest seabirds in the world, ranging from 13cm to 26cm in length, and are among the species we can see during our birdwatching tours.
What is the biggest seabird in Lisbon?
The biggest seabird you’ll likely see near Lisbon is the Northern Gannet (Morus bassanus). Very distinct for their white colouration with black wingtips and a yellow head, they are known for their high-speed plunge-dives and can reach 87-100 cm long, with a 165-180 cm wingspan and weigh around 2,4 to 3,6 kg, becoming the largest seabird in the North Atlantic and visible in Portuguese waters.
How do the seabirds sleep?
Seabirds can rest on land, and if they are in flight, they often sleep with only one side of their brain, leaving the other side awake. allowing them to stay above for weeks or months without landing, which is essential for navigating vast oceans. Most animals that sleep half-brained do so to stay alert for predators.
Are Seabirds monogamous?
Most seabirds are socially monogamous, meaning they form pairs for life to raise their young. Seabirds are long-lived and often must travel vast distances to find food. Raising a young child requires high investment from both parents, making it essential to have a reliable partner. This will increase the likelihood of producing and developing a good offspring. For most seabirds, if breeding is successful, they will continue breeding with the same partner until one member dies or doesn’t return to the breeding colony.
Do Seabirds attack?
Seabirds can attack, usually when nesting, mistaking food (especially gulls), or due to neurotoxin poisoning, causing erratic behaviour, but we never see this during the boat tours. Normally, the seabirds are afraid and vulnerable to human actions.
We had a blast on out sea birds boat tour. It was my first ever time watching birds in the open waters and it was amazing! I haven’t even dreamed to see this wonderful creatures so close! The main highlight for us was a small puffin and a dozen of razorbills. If you are a fan of birds I sincerely recommend you this tour.
Andrew S
Tripadvisor
Mini Glossary of Specific Terms
Kleptoparasitism
Stealing food from other birds (e.g. Skuas)s.
Scavenging
Feeding on dead organic matter or following ships.
Plunge Divers
Dive from the air into the water to catch prey.
Pattering
Walking on the surface with large feet.
Skimming
Flying low and touching the surface with the beak.
Dipping
Picking up prey with their beak while barely touching the water, like seagulls or terns.
Nuptial plumage
Also known as breeding plumage, refers to the vibrant, often more colourful feathers that male birds or females develop specifically for the mating season to attract mates, contrasting with their plainer winter plumage.
MPAs (Marine Protected Areas)
Marine protected areas such as seas, oceans, and estuaries.
Fledgling
Young bird learning to fly.
Scientific References
This guide is supported by scientific literature, field research, and the SeaEO team’s know-how. Below you can explore the main sources used.
Assírio & Alvim. Guia de aves. Porto: Assírio & Alvim, 2022. 448 p. (Coleção Rosa-dos-Ventos)
Cornell Lab of Ornithology. “Cornell Lab: All About Birds”. Cornell University. Accessed on: January 19, 2026
Dias, M. P., Martin, R., Pearmain, E. J., Burfield, I. J., Small, C., Phillips, R. A., Yates, O., Lascelles, B., Borboroglu, P. G., & Croxall, J. P. (2019). Threats to seabirds: A global assessment. Biological Conservation, 237, 525-537pp
Meirinho, A. et al. (2014/2015). Atlas das Aves Marinhas de Portugal. Sociedade Portuguesa para o Estudo das Aves (SPEA). Accessed on: January 19, 2026
Mitchell D. & Vulcan A. 2023, Annual Lifecycle of a Seabird – A winter break: life on the open sea (online), BirdLife International. Accessed on: January 19, 2026
Oró, D., & Martínez-Abraín, A. (2007). Ecology and Behaviour of Seabirds. Marine Ecology – Volume II (Encyclopedia of Life Support Systems – EOLSS), UNESCO-EOLSS Publishers, Oxford, Reino Unido
Signa, G., Vizzini, S., & Mazzola, A. (2021). Seabird influence on ecological processes in coastal marine ecosystems: An overlooked role? A critical review. Estuarine, Coastal and Shelf Science, 252, 107164