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
Bird extinction which results to the downfall of extinction. The most common disease affecting birds is Salmonellosis, which originates from the Latin name of salmonella. Infected birds pass bacteria in their fecal droppings. Other birds then become ill when they eat food contaminated by the droppings. Bird extinction Out of the approximately 10,400 known bird species, about 1,300 (13%) are classified as threatened with extinction, 9% as near threatened and of the remaining 78% many populations are declining. There is a general consensus among scientists who study these trends that if human impact on the environment continues as it has one-third of