On his Notes from Soggy Bottom blog, Bill Pulliam just posted a fascinating visualization of the spread of Eurasian Collared-Doves in the last couple decades. Using data from eBird, he compiled this animation of the range expansion between 1984 and 2010. The expansion is really quite impressive during the last ten years. One important thing to point out about the map, areas of gray indicate that people were submitting reports to eBird, but not reporting any collared-doves. The yellow are areas where no eBird reports were submitted from. Thanks to Bill for taking the time to put this together. Sounds like he is going to make similar maps for other species which will be very interesting.