Earth Witness Community
Celebrates the existence of and bears witness to species and natural places on the Earth that no longer exist in their natural state.
www.earthwitness.com
Hawaii's Extinct Species
Lists many of the birds, snails, insects, and plants to have met their demise though human intervention and pervasive alien introductions.
hbs.bishopmuseum.org/endangered/extinct.html
Amazing World of Birds: Extinction in Birds
Notes on recently extinct birds including the dodos, Hawaiian Drepanididae, Passenger Pigeon, Great Auk, and others.
www.earthlife.net/birds/extinction.html
Historical-Era Extinctions
Looks at how escalating human populations and their capacity to modify their surroundings are a significant influence on modern rates of extinction and endangerment.
www.uwsp.edu/geo/faculty/heywood/Geog358/endangr/HistExti.htm