Balearic Shearwater Bird Facts (Puffinus mauretanicus)

Visual Identification

Appearance

The Balearic Shearwater is a medium-sized seabird with a streamlined body adapted for efficient flight over water. Its upperparts are predominantly dark brown, contrasting with a white underbody. The bird has a distinctive pale underwing with dark edges and 'armpit' patches.

There is no significant difference between males and females, although males are usually fractionally larger. Juveniles closely resemble adults, though they may appear slightly 'fresher-plumaged'.

Size

Length

35cm to 40cm

Wingspan

85cm to 90cm

Weight

480g to 535g

Colours

Males and females have similar plumage

Primary Colour

Brown White

Secondary Colour

Grey

Beak Colour

Grey

Leg Colour

Pink

Habitat and Distribution

Habitats

Woodland

The Balearic Shearwater is not typically found in Woodland habitats.

Garden

The Balearic Shearwater is not typically found in Garden habitats.

Wetland

The Balearic Shearwater is not typically found in Wetland habitats.

Coastal

The Balearic Shearwater can be found in Coastal habitats.

Urban

The Balearic Shearwater is not typically found in Urban habitats.

Farmland

The Balearic Shearwater is not typically found in Farmland habitats.

Grassland

The Balearic Shearwater is not typically found in Grassland habitats.

Desert

The Balearic Shearwater is not typically found in Desert habitats.

Tundra

The Balearic Shearwater is not typically found in Tundra habitats.

Rainforest

The Balearic Shearwater is not typically found in Rainforest habitats.

Mountain

The Balearic Shearwater is not typically found in Mountain habitats.

Savanna

The Balearic Shearwater is not typically found in Savanna habitats.

Distribution

Balearic Shearwaters breed exclusively on Spain's Balearic Islands in the Mediterranean Sea. During the breeding season, they are found in coastal waters around these islands and along the nearby Spanish and North African coasts.

Post-breeding, they disperse widely into the Atlantic, with significant numbers reaching waters off the UK, Ireland, and France. Some birds venture as far north as the North Sea, while others move south along the West African coast.

Elevation Range

Sea level to 100 meters

Climate zones

Mediterranean, Temperate

Distribution Map

This map gives you a rough idea of where you might spot a Balearic Shearwater. The coloured areas show countries where these birds have been seen.

A few things to keep in mind:

Birds might not be everywhere in the coloured areas, for example, they may be present around the coast of that country
Where birds live can change with seasons and available food
This map is quite simple - it doesn't show exact locations

We're working on making our maps even better! Soon, we hope to show you:

More detailed maps for bigger countries, including state and region
How birds move around during different seasons

Resident

Breeding

Non-breeding

Vagrant

Distribution by Region

Species that can be found in the area throughout the year

France Italy Portugal Spain The United Kingdom

Species that are present in the area during their breeding season

Algeria Morocco

Species that are present in the area outside their breeding season

Gibraltar

Species that appear infrequently (rare) and unpredictably outside their normal range

Albania Belgium Bosnia and Herzegovina Croatia Denmark Faroe Islands Germany Greece Israel Libya Malta Monaco Montenegro Netherlands Norway Poland Slovenia Sweden Tunisia

Behaviour and Ecology

Bird Attributes

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Bird Attributes Explained

Our bird attributes system rates various aspects of a bird's capabilities on a scale of 0-100, based on data from field observations, scientific studies, and expert knowledge.

Attribute Categories:

Agility: Manoeuvrability, speed, and grace in flight or movement.
Strength: Physical power, often correlating with size and hunting abilities.
Adaptability: Ability to thrive in various environments or changing conditions.
Aggressiveness: Territorial behaviour and assertiveness, particularly during breeding seasons.
Endurance: Stamina, often seen in migration patterns or foraging behaviours.

Understanding the Ratings:

0-20: Very Low
21-40: Low
41-60: Average
61-80: High
81-100: Very High

Remember, these attributes are relative to other bird species and don't necessarily indicate superiority.

Hover over the icon next to each attribute for more information.

Tap the icon next to each attribute for more information.

Agility 85

Agility

Reflects the bird's manoeuvrability, speed, and grace in flight or movement.

The Balearic Shearwater demonstrates remarkable agility with its characteristic low, gliding flight pattern over waves and ability to manoeuvre efficiently in coastal and pelagic environments. Its streamlined body and adept flying skills contribute to its high agility rating.

Strength 60

Strength

Indicates the bird's physical power, often correlating with size and hunting abilities.

Whilst not exceptionally strong for its size, the Balearic Shearwater possesses adequate strength to dive up to 30 metres deep for prey and to undertake long-distance migrations. Its medium build suggests moderate strength relative to other seabirds.

Adaptability 75

Adaptability

Represents the bird's ability to thrive in various environments or changing conditions.

These shearwaters show considerable adaptability in their feeding habits, capable of surface-seizing, shallow plunge-diving, and following fishing vessels for discards. Their ability to thrive in both Mediterranean and Atlantic waters also indicates good adaptability, though their specific breeding requirements limit a higher score.

Aggressiveness 40

Aggressiveness

Measures the bird's territorial behaviour and assertiveness, particularly during breeding seasons.

Balearic Shearwaters are not notably aggressive birds. They form large, dense flocks when feeding, suggesting a relatively sociable nature. However, they likely display some aggression in defending nesting sites, as is common in seabirds, hence the moderate score.

Endurance 80

Endurance

Reflects the bird's stamina, often seen in migration patterns or foraging behaviours.

The Balearic Shearwater exhibits impressive endurance, undertaking long-distance migrations and spending most of its life at sea. Its ability to cover vast oceanic areas, from the Mediterranean to the North Sea, and its longevity of up to 25 years in the wild, despite conservation challenges, indicate high endurance.

Diet

Balearic Shearwaters primarily feed on small pelagic fish such as sardines and anchovies. They also consume squid, molluscs, and crustaceans.

These birds often feed by surface-seizing or shallow plunge-diving into the waves and are known to follow fishing vessels to scavenge discards.

Behaviour

Balearic Shearwaters are highly pelagic, spending most of their lives at sea. They exhibit a characteristic low, gliding flight pattern, often skimming close to the water's surface.

These birds form large, dense flocks when feeding, particularly during their post-breeding dispersal into the Atlantic.

Vocalisation

Balearic Shearwaters produce eerie, wailing calls at breeding colonies, often described as a mournful 'aaa-ooo' or 'ar-oo'. These vocalisations are typically heard at night when birds return to their nesting sites. At sea, they are generally silent.

Nesting & Breeding

Balearic Shearwaters form monogamous pairs and breed annually. The breeding season typically begins in February when birds return to their colonies.

They nest in burrows, crevices, small caves, and small islets on coastal cliffs. Females lay a single white egg directly on the ground or in a small nest of vegetation.

Both parents share incubation duties for about 50 days. After hatching, chicks are fed by both parents and fledge after approximately 60-70 days, usually in June or July.

Conservation and Status

Global Conservation Status

Critically Endangered ^[1]

The Balearic Shearwater is critically endangered due to multiple threats. These include predation by introduced mammals at breeding sites, accidental bycatch in fishing gear, and climate change impacts on their marine habitat.

Urgent conservation efforts are underway to protect breeding colonies and reduce at-sea mortality.

Population Data

Global Population Estimate

19,000 mature individuals ^[2]

Global Population Trend

^[3]

Trend data may be uncertain or fluctuating

Birdwatching Tips

Look for them during 'sea watching' sessions from coastal headlands, especially in late summer and autumn.
Focus on their distinctive low, gliding flight pattern close to the water.
Watch for flocks feeding in areas of upwelling or where fish shoals are present.
In the UK, the best viewing opportunities are often off the southwest coast.

Additional Information

Quick Facts

Other names:

Baldriga balear (Catalan)

Family:

Procellariidae

Average Lifespan

12 years

Max Lifespan

23 years

Predators

Main predators include Yellow-legged Gulls, which prey on eggs and chicks, and introduced mammals such as cats and rats at breeding sites.

Did You Know?

Balearic Shearwaters can dive up to 30 meters deep to catch prey.
They are the most endangered seabird in Europe, with a rapidly declining population.
These birds can live up to 25 years in the wild despite their current conservation challenges.

FAQs

What is the difference between Manx shearwater and Balearic shearwater?

Manx shearwaters and Balearic shearwaters are very similar in appearance; however, there are a few subtle differences that make it possible to tell them apart.

Balearic shearwaters are larger than Manx shearwaters, and their plumage is lighter and less contrasting. Their calls are also slightly higher in pitch. Manx shearwaters are far more abundant, with more than 300,000 pairs breeding on coastal islands around the UK.