As part of a national bird census organized by the Audubon Society, a Christmas Bird Count has been held in the Fermilab area every year since 1976. The count is performed by groups of volunteer birdwatchers who spend the day counting all the birds they can find in a circle which is 15 miles in diameter and centered on the northern boundary of the Fermilab site. The exact date of the count varies but is always on a Saturday about a week before Christmas day. (So far, the earliest date was Dec 14 and the latest was Dec 21.) These pages summarize the results from the Fermilab part of the count as well as the results from the entire count circle.
Both the number of individual birds and the number of species counted has increased over time. This trend in large part reflects an increase in the number of volunteers and hence in the total area covered by the count. Despite this bias, some interesting changes in some of our bird populations are evident in the data.