The North American Bird Phenology Program

mIEKAL
- April 06, 2009

The North American Bird Phenology Program houses a unique and largely forgotten collection of six million Migration Observer Cards that illuminate migration patterns and population status of birds in North America. These handwritten cards contain almost all of what was known of bird distribution and natural history from the Second World War back to the later part of the 19th century. The bulk of the records are the result of a network of observers who recorded migration arrival dates in the spring and fall that, in its heyday, involved 3000 participants.

http://www.pwrc.usgs.gov/bpp/about.cfm