Geological history records five major periods of species extinction during the last 600 million years. While events on a global scale range from a meteorite collision to glaciation and climate warming are believed to have caused these massive eradications in the past, the list of wildlife casualties in North America since European settlement tells us human action is now the greatest threat to plants and animals.
The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) is charged with determining
the list of Canada's endangered species. In April, COSEWIC, which is made up of government
officials, conservationists and academics, releases its annual list of species at risk in
Canada. There are currently 307 species on the list, and an average of 10 to 20 species are
added each year. COSEWIC cautions that this does not necessarily reflect the rate at which
species are becoming at risk, but simply reflects the rate at which the committee is able
to examine each species. More than 6,000 additional species within the taxonomic groups that
are currently considered by COSEWIC require attention.
The list categorizes mammals, birds, amphibians, reptiles, fish, molluscs and plants as
endangered (facing imminent extinction), threatened (likely to become endangered if limiting
factors not reversed) or vulnerable (particularly sensitive to human activities or natural
events). There are currently 10 extinct species listed.
(Information from Canadian Geographic Endangered Species map and COSEWIC
Endangered species on the Web
Endangered Species (Adobe PDF document)