This is a great program to participate in; it is associated with Cornell University and has been monitoring bird populations all over the country for a number of years. The data is used to follow bird numbers from year to year. Participants have access to their data and to data from their area as well as all over the country. You can observe for just one day or for all four days. If you like birds and nature, this is a great and satisfying program to participate in! Click on the photo below to go to their web site.