White-throated Sparrow by Gary Mueller/PFW
We’ve said many times that
entering data into our eBird
program is a great way to
make your hobby count toward something
bigger. Now a paper in the journal
Public Library of Science Biology (PLoS)
says so, too.
The report describes eBird, a
nine-year-old project by the Cornell Lab
of Ornithology and Audubon, as an example
for researchers interested in the
power of human computation—tapping
the human brain to do things that computers
can’t yet do. For eBird that task is
identifying birds, but other projects involve
identifying galaxies, deducing the
folded structures of proteins, and digitizing
books one word at a time.
The paper’s authors—all members of
the Cornell Lab’s Information Science
program—discuss how eBird has succeeded in recruiting a volunteer workforce.
They stress the importance of
knowing their audience, offering tools
(such as personal checklists and sightings
maps) that give back to the user,
and devising ways to ensure data quality
without making data entry onerous. The
reward for successfully balancing these
concerns has been the emergence of a vibrant
community of eBirders and the immense,
global database of observations
they have built.
One way those data have begun bearing
fruit is in the form of a new kind of
range map—one that moves before your
eyes. eBird’s new animated occurrence
maps statistically model a species’ occurrence
across North America for each
week of the year—in essence producing
52 separate range maps for each species.
By flashing them on your computer
screen in sequence, you can watch a species ebb and flow over the continent.
As an example, consider the White-throated
Sparrow. Field guides tell you
these handsome little sparrows winter in
the East and move northward in summer.
But we’re basically left to guess about the
routes and timing of migration.
The figure at right shows three excerpts
from an animated occurrence
map. Shading corresponds to the likelihood
of occurrence—another difference
over typical range maps. The first
map shows how the birds start the year
mainly in low-elevation parts of the
East. By May they are moving north,
mainly through Minnesota and Michigan
but also in Wisconsin and New
England. By early June they’re almost
all gone from the United States. When
will they return? See the full 52-
map animation here.
Watching these new maps change
as a year sweeps past can be as mesmerizing
as it is informative (see maps
for 50 common species here). Just remember to keep
birding and to enter your own data into
eBird, where your contributions can take
shape right before your eyes.