The Richest Avifauna in the world
South America – over 2,500 breeding species
The Neotropical Region — South America, known as the ‘bird continent’, is already credited with over 2,500 breeding species and much of the area is still largely unexplored.
There is, of course, overlap between regions, and seabirds are more easily grouped by the ocean than land-mass, but the number of breeding species of the other regions can be given approximately as: Palearctic (Europe, Africa north of the Sahara, and arctic, boreal and temperate Asia north of the Himalayas) about 950, Nearctic (North America north of the tropics) 750, Afrotropical (Africa south of the Sahara but excluding Madagascar and the Comoro Islands while including the islands of Zanzibar, Penbra, Mafia and the Gulf of Guinea) over 1,500 and Australasia (Australia, New Zealand, New Guinea and all island about dependencies) 1,100, seasonal migrants apart. Colombia is the country with the highest number of breeding species — over 1,700.
The Poorest Avifauna in the World
The Antarctic ‘Mainland’ – 11 breeding species
Within the Antarctic Circle only 11 bird species breed regularly. These are the Antarctic petrel (Thalassoica antarctica), adélie penguin (Pygoscelis adeliae), snow petrel (Pagodroma nivea), Antarctic skua (Catharacta maccormicki), emperor penguin (Aptenodytes forsteri), chinstrap penguin (Pygoscelis antarctica), southern giant petrel (Macronectes giganteus), Antarctic fulmar (Fulmarus glacialoides), cape pigeon (Pintado petrel) (Daption capense), Antarctic prion (Pachyptila desolata) and Wilson’s storm petrel (Oceanites oceanicus).
A wider variety of species breed within the strict geographical definition of Antarctica, including the entire Antarctic Peninsula, its off-lying islands, sea ice and surrounding ocean and islands northwards to the Antarctic Convergence.
The only terrestrial birds in Antarctica are the snowy or yellow-billed sheathbill (Chionis alba) and black-faced or black-billed sheath-bill (Chionis minor), which are related to the pigeons. These peculiar birds are a possible evolutionary link between shorebirds and gulls.
They have a rudimentary spur on the carpal joint of the wing (the forming the forward-‘wrist’, pointing part of the folded wing) and a broad, strong bill with a horny sheath which partially covers the nostrils. Natural- food includes stillborn seal pups and afterbirths, penguin eggs and droppings, and krill which they force penguins to regurgitate. But they are opportunist feeders with a varied diet and in winter scavenge the rubbish tips of whaling stations and Antarctic survey bases.