The Number of Albatross (Diomedeidae) Species

The basis of the widespread practice of recent years to recognise 23 or 24 species of albatross is critically ex- amined. In large part this can be traced back to an analysis which split the traditional species of albatross on the basis of theoretical fiat: the embrace of the narrow Phylogenetic Species Concept. The role of conservation concerns in albatross taxonomy is examined and rejected. Claims that introgression is likely to explain the low cytochrome-b distance found be- tween many "new" albatross species are rejected. An analysis of climatic conditions at albatross breeding colonies can ex- plain plumage differences in the ontogeny of albatross taxa, and plumage colouration can be related to differing environ- mental pressures. It is concluded that the variation among taxa within albatross taxa is ecophenotypic. Finally, it is sug- gested that a plausible mechanism for such variation can be found in epigenetics.