I think my favorite product or application from eBird has to be their “Occurrence Maps” produced by their innovative Spatio-Temporal Exploratory Model (STEM) maps. Here’s how they describe the process and the data used to construct these maps, direct from the eBird website:
“We are excited to display the preliminary results of our modeling research using eBird data. These maps, which are called STEM (Spatio-Temporal Exploratory Model) maps, use eBird stationary and traveling count checklists that report all species. The location of each checklist is associated with remotely-sensed information on habitat, climate, human population, and demographics generating a suite of approximately 60 variables describing the environment where eBird searches take place. By relating these environmental variables to observed occurrences, STEM is used to make predictions at unsampled locations and times. Models are trained one species at a time. Following model training, the expected occurrence for that species is predicted on each of 52 days, one per week throughout 2009, at some 130,000 locations sampled throughout the conterminous US. This massive volume of information is then summarized on maps, which in many cases reveal novel information about the annual cycles of North American birds. These maps showcase the power of eBird – year-round, continental-scale monitoring of all species.”
Here, for example, is a STEM map for Louisiana Waterthrush (the Pinnacle of Avian Evolution) for March 15th:
. . . and for May 31:
Louisiana Waterthrush is a great example to study, because the description on the site explains what works about the model (migration timing) and what doesn’t (the birds are predicted in the Black Hills – where they don’t occur – and overpredicted in the extreme Northeast where they might be present but are quite rare).
The STEM maps are cool enough as static images, but the real magic happens when you see them animated. I was part of a group gathered around eBird’s Brian Sullivan at the Partners in Flight meeting last August as he essentially took requests from the audience to display STEM maps for various species on a big flatscreen TV. STEM is just one way that eBird is helping us visualize distributions and migration as never before.