Biodiversity: North America

Numbers of threatened vertebrates: North America

Note: critically endangered (extremely high risk of extinction in immediate future); endangered (very high risk of extinction in near future); vulnerable (high risk of extinction in medium-term future) The data include all globally threatened vertebrate species with country records in the UNEP-WCMC database (UNEPWCMC 2001a). Marine species recorded by ocean area are not included

Habitat destruction and degradation is the most
pervasive threat to biodiversity in the region (Wilcove
and others 2000). North American wetlands have high
biological productivity, providing critical habitats for
many species and essential ecological services such as
taking up floodwaters and protecting water quality by
filtering pollutants (Schmid 2000). Wetland protection
is therefore a priority issue for biodiversity
conservation in North America. Another key issue is
the threat that non-native species pose to native
species through predation, competition, parasitism and
hybridization.

North America contains many different ecosystems, with biodiversity increasing along a northsouth gradient and the Hawaiian Islands containing the highest diversity of species. North America contains a large percentage of the world's wetlands with Canada holding about 24 per cent, accounting for about 16 per cent of its landscape (NRC 2001). Wetlands cover about 264 million ha of North America.

According to Canada's endangered species list, as of May 2001 a total of 352 species were at risk of imminent or eventual extinction (endangered, threatened or of special concern) while in the United States 1 231 species were listed as endangered or threatened (Alonso and others 2001, COSEWIC 2001). Some 309 vertebrate species are threatened with extinction in the region (see bar chart).

To safeguard biological diversity, North America has set aside protected areas. More than 14 per cent of the region's land area is now protected, with 4 521 protected sites covering an area of some 264 million ha (UNEP-WCMC 2001b). Canada has signed and ratified the Convention on Biological Diversity (CBD) and continues to work towards introducing a federal Species At Risk Act. The United States is not yet party to the CBD but has a strong Endangered Species Act. The latter has been used effectively by NGOs to protect substantial areas of habitat for threatened species.