Description

Frequency of taxon groups on the U.S. Fish and Wildlife Service list of endangered and threatened species (2002).

Format

A data frame with 11 observations on the following 2 variables.

taxon

a character vector

num.species

a numeric vector

Source

U.S. Fish and Wildlife Service. 2001. Number of U.S. listed species per calendar year.

References

http://www.fws.gov/endangered/

Examples