North American Bird Phenology Program

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 status 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. Today, those records are being processed and placed online where volunteers, worldwide, can go onto the BPP website and transcribe these images into our database for analysis. This information will be used, along with recently collected arrival times of migrant birds, in conjunction with historical weather data to show how migration is affected by climate change.