Yelkouan shearwater Menorca. A study of these birds recommended that a combination of morphological characteristics and DNA sequence data should be required at least for scientific purposes to assign individual birds to either species. It was formerly considered a subspecies of the Manx shearwater (see there for more on the "Puffinus puffinus" superspecies). After the first split, it was the nominate subspecies of the so-called "Mediterranean shearwater" for nearly ten more years; it is considered a monotypic species now, as the Balearic form "mauretanicus" has been separated as the Balearic shearwater. The yelkouan shearwater appears to belong to a group of Mediterranean
Galápagos shearwater white. It sometimes has a dark collar. Both sexes are alike, as are the young after fledging. It is a slender-bodied shearwater, about 29–31 cm long, with a wingspan of around 63 cm and weighs 123-225 g. The species closely resembles the tropical shearwater, although the latter is typically blacker and has a longer tail. The Galápagos shearwater is a gregarious species and will feed at sea with other shearwaters and boobies. It flies low over the water and feeds on squid, fish and offal. It intersperses 4-10 stiff wing beats with shallow glides. Galápagos shearwater The Galápagos shearwater ("Puffinus