eBird Abundance Models provide an unparalleled window into the full annual cycle of bird populations in the Western Hemisphere. These species distribution models have been specifically developed for eBird data by statisticians and researchers at the Cornell Lab of Ornithology. These models were first released in 2009 and have since been used in a number of papers and reports including three State of the Birds Reports, most recently in 2016.
eBird Abundance Models take all of the eBird data from birdwatchers in the Western Hemisphere, add a suite of environmental variables, and produce predictions of where birds are on the landscape. The power of these models is the ability to standardize the variety of data that people collect in their eBirding, and extrapolate the data that we have to make predictions in places where nobody has ever eBirded. Each 8km pixel in these models gives a specific prediction for the expected number of individuals you could expect to encounter at a given location if you went birding for one hour at 7am covering one kilometer of distance.
Notable in these models is that they’re actually predicting the number of birds you’d encounter, which is why counting birds matters! Understanding abundances of birds is immensely more valuable for conservation, since it lets you know where the bulk of the population is at any given time, instead of just understanding whether any individuals of that species is present (which is all that you can know from an “X” on your checklist).
Our Help Center has more information on eBird models.
Wood Thrush (Hylocichla mustelina) is a well-known forest species, especially so in the eastern United States where its melodic song rings through eastern forests from May to July. It migrates to Central America for the winter, where it also prefers dark, close-canopy broadleaf forests, very similar to its breeding grounds. During the winter it is much less conspicuous, largely detected by its chattering call notes and occasionally flushed from forest trails.
Indigo Bunting (Passerina cyanea) is a familiar summer bird in the eastern United States and southern Canada, with males sporting an almost unnatural hue of bright blue that is richer on the face than on the breast and back. In the fall and winter males lose their blue plumage and resemble the brown females.
Barn Swallow (Hirundo rustica) may be the most widespread and well-known passerine, with highly migratory populations that span the Americas as well as Europe, Asia, and Africa. Related species, and some Barn Swallow subspecies, are resident in Africa, the Middle East, and Australia. This remarkable variability makes Barn Swallow a great case study in migratory behavior. The varied migratory behaviors in this species globally are also seen on a smaller scale in the Americas, as this new eBird Abundance Model map helps illustrate.