The Balearic shearwater (Puffinus mauretanicus) is a medium-sized shearwater in the seabird family Procellariidae
Balearic shearwater is 34–39 cm (13–15 in) in length and has a wingspan of 78–90 cm (31–35 in). 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, this species is very similar to the Manx and yelkouan shearwaters found elsewhere in the Mediterranean. At least one mixed breeding colony of Balearic and yelkouan shearwaters exists on Menorca, 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.