Alfred Russel Wallace

“ The Anseres, or Swimmers, being truly aquatic birds, possess, as might be expected, a large number of cosmopolitan families and genera. No less than 5 out of the 8 families have a world-wide distribution, and the others are characteristic either of the North or the South Temperate zones. Hence arises a peculiarity of distribution to be found in no other order of birds; the Temperate being richer than the Tropical regions. The Nearctic and Palæarctic regions each have seven families of Anseres, two of which, the Colymbidæ and Alcidæ, are peculiar to them. ”

“ Equally remarkable is the development of these large forms of wingless birds in Australia and the adjacent islands, and especially in New Zealand, where we have evidence which renders it probable that about 20 species recently coexisted. This points to the conclusion that New Zealand must, not long since, have formed a much more extensive land, and that the diminution of its area by subsidence has been one of the causes—and perhaps the main one—in bringing about the extinction of many of the larger species of these wingless birds. ”

“ The Ethiopian, Australian, and Neotropical regions, which all extend into the South Temperate zone, have six families, with one peculiar to them; while the Oriental region, which is wholly tropical, possesses the five cosmopolitan families only. ”