Bewick Swan Research in the Netherlands - Summaries of research on Cygnus (columbianus) bewickii from the Netherlands Institute of Ecology. www.nioo.knaw.nl/training/Pdi-stage2.htm
Bewick's Swan - Short article on Cygnus columbianus in Britain. www.birdsofbritain.co.uk/bird-guide/bewick-swan.htm
Cygnus buccinator - Animal Diversity Web article about the trumpeter swan. animaldiversity.ummz.umich.edu/accounts/cygnus/c._buccinator$narrative.html
Cygnus olor - Article about the mute swan, from Animal Diversity Web. animaldiversity.ummz.umich.edu/accounts/cygnus/c._olor$narrative.html
Did Trumpeter Swans Ever Breed in Eastern North America? - Discussion by Bill Whan and Gerry Rising of the controversial program for introduction of Cygnus buccinator into the eastern US. www.acsu.buffalo.edu/~insrisg/nature/swans.html
Trumpeter Swan - An Alberta Endangered Species - Trumpeters are the rarest swan in the world. They used to be abundant in North America but by the early 1900s, they were nearly extinct. raysweb.net/specialplaces/pages/swan.html
