eBird Launches New Animated Migration Maps
eBird is a free online tool for birders that allows you to record the birds you see and keep track of your lists anywhere around the world. Each time you submit an observation to eBird, the record is permanently archived, made available to birders, and also to researchers and conservationists. Our simple hypothesis is that data collected by birders can help scientists better understand bird population dynamics and occurrence.
Recently, we've started to reveal some of the preliminary results of our efforts to model bird distribution at large scales using eBird data. Basically, these models correlate bird occurrence (i.e., your bird observations) with a suite of remotely-sensed variables (e.g., land-cover, climate) to create predictive surfaces of bird distribution at very large scales for each day of the year. By looking at these surfaces across time, we can begin to explore patterns in how bird populations migrate. Check out the Swainson's Hawk animation for a good example of differential migration. This analysis technique, called Spatio Temporal Exploratory Modeling, was recently published in Ecological Applications, but we're also featuring new results on the eBird website.
The image above is an estimated occurrence map for American Pipit on 25 October 2008, at the tail-end of fall migration.
Each visualization on the eBird site has a brief analysis authored primarily by Marshall Iliff. These notes help the reader interpret what's happening on the maps, and also provide some biological grounding for observed patterns. Marshall also does a great job outlining the caveats associated with these maps, and while there's no doubt that these are far from perfect in some cases, we're really excited by these results. We invite you to enjoy these new migration animations, and comment about them here or on the eBird Blog.
Your continued participation in eBird will greatly improve our ability to model bird distribution at large scales, and we appreciate all your efforts!