Estimates of recent and future extinction rates

group number of living species number of extinctions per indicated time period (in years) extinctions per million species

per year

Recent extinctions

birds (described 1800-99) 7,079 39/100 55

mammals 4,300 60/200 70

reptiles 4,700 20/200 21

frogs and toads 4,000 5/25 50

freshwater clams 1,082 21/100 194

Future extinctions*

birds 10,000 1,200/100 1,200

mammals 4,300 650/100 1,512

reptiles 4,700 210/100 447

frogs and toads 4,000 89/100 223

freshwater clams 1,082 120/100 1,109

*Predictions of future extinctions for all species, as published by various authors since about 1980, range between 1,000 and 10,000 extinctions per million species per year.

Principal source: S.L. Pimm et al., "The Future of Biodiversity," Science 269:347–350 (1995).