Audubon's 116th Christmas Bird Count ends Tuesday.
Hundreds of central Floridians joined the wildlife census that has drawn bird lovers from across the nation for more than a century.
The data they collect indicates how bird populations are doing. Researchers and wildlife agencies use the data to develop conservation strategies and identify environmental problems.
John Thomton led two groups of bird counters in central Florida. He says development is disrupting habitats, and this winter's warm weather has affected duck populations.
"You think, Oh no what's happening to all our ducks? But you have to remember that it's been really warm up north this year, and there hasn't been as much icing of lakes and ponds up north. And so birds didn't have to come as far south at least so far this winter."
The annual count began in 1900 and is a holiday tradition for many birders.