The Balearic shearwater (''Puffinus mauretanicus'') is a medium-sized shearwater in the

seabird Seabirds (also known as marine birds) are birds that are adaptation, adapted to life within the marine ecosystem, marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent ...

family ''Procellariidae''. ''Puffinus'' is a

Neo-Latin Neo-LatinSidwell, Keith ''Classical Latin-Medieval Latin-Neo Latin'' in ; others, throughout. (also known as New Latin and Modern Latin) is the style of written Latin used in original literary, scholarly, and scientific works, first in Italy d ...

loanword A loanword (also a loan word, loan-word) is a word at least partly assimilated from one language (the donor language) into another language (the recipient or target language), through the process of borrowing. Borrowing is a metaphorical term t ...

based on the English "puffin" and its variants, that referred to the cured carcass of the fat nestling of the Manx shearwater, a former delicacy. The specific ''mauretanicus'' refers to

Mauretania Mauretania (; ) is the Latin name for a region in the ancient Maghreb. It extended from central present-day Algeria to the Atlantic Ocean, Atlantic, encompassing northern present-day Morocco, and from the Mediterranean Sea, Mediterranean in the ...

, an old name for an area of North Africa roughly corresponding to Morocco and Algeria. The Balearic Shearwater is listed

critically endangered An IUCN Red List critically endangered (CR or sometimes CE) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of t ...

by the

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

and is one of Europe's most endangered seabirds.

Taxonomy

The Balearic shearwater was formerly described in 1921 by the English ornithologist Percy Lowe. He treated it as a

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

of the Manx shearwater and coined the trinomial name ''Puffinus puffinus mauretanicus''. The Balearic shearwater was long regarded a subspecies of the Manx shearwater. Following an initial split, it was held to be a subspecies of the "Mediterranean shearwater" for nearly ten more years, until it was resolved to be a distinct

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

, separate from the yelkouan shearwater. It is the last

taxon In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

of the ''Puffinus'' complex that was recognized as a separate entity. A

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

study published in 2021 found very little genetic difference between the Balearic shearwater and the yelkouan shearwater (''Puffinus yelkouan''). The authors of the study suggested that these two taxa might be better considered as conspecific. It appears to belong to a group of

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

and adjacent Atlantic species which includes the yelkouan shearwater and one to three prehistorically

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

taxa, Hole's and possibly also Olson's shearwater and an undescribed form of unclear distinctness from

Menorca Menorca or Minorca (from , later ''Minorica'') is one of the Balearic Islands located in the Mediterranean Sea belonging to Spain. Its name derives from its size, contrasting it with nearby Mallorca. Its capital is Maó, situated on the isl ...

. The two living Mediterranean lineages had probably separated before the end of the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58mya), as indicated by molecular differences and the Ibizan fossil '' Puffinus nestori'' from the Late Pliocene or Early

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

, which may have been the direct ancestor of the present species.

Description

Balearic shearwater is in length and has a wingspan of . It has the typically "shearing" flight of the genus, dipping from side to side on stiff wings with few wingbeats, the wingtips almost touching the water. This bird looks like a flying cross, with its wing held at right angles to the body, and it changes from dark brown to dirty white as the dark upperparts and paler undersides are alternately exposed as it travels low over the sea. Apart from its less contrasting

plumage Plumage () is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, there can b ...

, this species is very similar to the Manx and yelkouan shearwaters found elsewhere in the

. At least one mixed breeding colony of Balearic and yelkouan shearwaters exists on

, and the species' winter ranges overlap in the Central Mediterranean; for scientific purposes at least, a combination of morphological characteristics and DNA sequence data is suggested to identify the species.

Distribution and habitat

This species breeds on islands and coastal cliffs in the

Balearic islands The Balearic Islands are an archipelago in the western Mediterranean Sea, near the eastern coast of the Iberian Peninsula. The archipelago forms a Provinces of Spain, province and Autonomous communities of Spain, autonomous community of Spain, ...

. Most winter in that sea, but some enter the Atlantic in late summer, reaching north to

Great Britain Great Britain is an island in the North Atlantic Ocean off the north-west coast of continental Europe, consisting of the countries England, Scotland, and Wales. With an area of , it is the largest of the British Isles, the List of European ...

and

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

Behaviour

This is a gregarious species, which can be seen in large numbers from

boat A boat is a watercraft of a large range of types and sizes, but generally smaller than a ship, which is distinguished by its larger size or capacity, its shape, or its ability to carry boats. Small boats are typically used on inland waterways s ...

s or headlands, especially in autumn. It is silent at sea, but at night the breeding colonies are alive with raucous cackling calls, higher pitched than the Manx shearwater's.

Breeding

This species nests in burrows and

cave Caves or caverns are natural voids under the Earth's Planetary surface, surface. Caves often form by the weathering of rock and often extend deep underground. Exogene caves are smaller openings that extend a relatively short distance undergrou ...

s which are visited only at night to avoid predation by large gulls.

Feeding

The Balearic shearwater feeds on

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

and

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

s. It does not follow boats.

Conservation and threats

The Balearic shearwater is considered

with extinction by the

. Recent models estimate a mean decrease of 7.4% per year and a mean extinction time of 40.4 years. This equates to an ongoing decline of more than 80% over the next three generations (54 years). It is under severe threat from the development of holiday resorts near its breeding sites. These can destroy or alter its natural breeding habitat by, for example, producing light pollution around nesting colonies. Predation from introduced animals such as cats and rats also cause problems. The discovery of yelkouan shearwaters in the Menorcan colony suggests that hybridization may also pose a problem. A further problem for conservation of the Balearic Shearwater is that 25 official languages are spoken across its distribution, hampering the dissemination of conservation information. The Balearic shearwater is one of the species to which the Agreement on the Conservation of Albatrosses and Petrels applies.

References

External links

BTO BirdFacts - Balearic shearwater
* ttps://www.flickr.com/search/groups/?w=42637302@N00&q=balearic+shearwater&m=pool Flickr Field Guide Birds of the WorldPhotographs
Oiseaux
{{Taxonbar, from=Q704081 Balearic shearwater Balearic shearwater Birds of Europe Birds of Ibiza Birds of North Africa Endemic fauna of the Balearic Islands Balearic shearwater Balearic shearwater