Figure 2.20. Percentage of known species threatened in North America, 1990s.

IUCN (1993); WCMC (1992, 1994, 1995).
The number of threatened species listed for all countries includes full species that are classified by the World Conservation Union (IUCN) as endangered, vulnerable, rare, and indeterminate, but excludes introduced species, species whose status is insufficiently known, or those known to be extinct.