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
Chagos Archipelago fuscata"), brown and lesser noddies ("Anous stolidus" and "Anous tenuirostris") wedge-tailed shearwaters ("Puffinus pacificus") and red-footed boobies ("Sula sula"). Land bird fauna is poor and consists of introduced species and recent natural colonisers. Red fody had been introduced and now widespread. Environments of Chagos Archipelago provides rich biodiversity and support varieties of cetacean species within the vicinity, such as three populations of blue whales and toothed whales (sperm, pilot, orca, pseudo-orca, risso's and other dolphins such as spinners, and so on). Dugongs, being locally extinct today, once thrived in the archipelago and the Sea Cow Island was named after the