arose from reptiles some 225 million years ago, developing feathers and
lightweight skeletons. In some, the necessary adaptions for sustained flight
evolved, including a cardiorespiratory system composed of a powerfull four
chambered heart and efficient counter-current gas exchange across the lungs.
There are some 1700
bird species in North America, but if you exclude Central America, that
number drops to about 645. This page covers those species found in or around
the Great Lakes.
list of works cited in the "Canada's Aquatic Environments: Birds"
links to other avian sites.
and find information on Canada's aquatic birds.
knowledge of Great Lakes birds by doing a little birdwatching.