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
Storrs L. Olson world's foremost paleornithologists. He was also the 1994 recipient of the Loye and Alden Miller Research Award. He was formerly curator of birds at the United States National Museum of Natural History; , he holds an emeritus position in the institution. Several prehistoric bird species have been named after Olson, including "Nycticorax olsoni", "Himantopus olsoni", "Puffinus olsoni", "Primobucco olsoni", "Gallirallus storrsolsoni", and "Quercypodargus olsoni". Storrs L. Olson Storrs Lovejoy Olson (born April 3, 1944) is an American biologist and ornithologist who spent his career the Smithsonian Institution, retiring in 2008. One of the world's foremost avian paleontologists, he is best