When is a Junco a Junco?
Scientists continue to change the names of
birds.
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| Why is it that birds of the same species
may look very different in various regions, but have the same name? For instance,
Dark-eyed Juncos in the Pacific Northwest may have a reddish back and a dark
“hood” (Oregon race), while Dark-eyed Juncos in the northeast are generally a
slate-gray color, without a hood (slate-colored race). Who decides where the lines are
drawn between species? Why can birds that look very similar, like Black-capped Chickadees
and Carolina Chickadees, be distinct species, while others that look obviously different,
like Dark-eyed Juncos from the Oregon and slate-colored races, be the same species? |
| Dark-eyed Juncos of the "Pink-sided"
race, like the bird seen here, commonly winter in Colorado, Arizona, New Mexico, western
Texas, and northern Mexico. Photo by Vernon
Dayhoff, Colorado Springs, CO. |
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 A history of name changes
Committees of 8-10 highly experienced ornithologists and taxonomists
make official changes in species names. For North American birds, the Committee on
Classification and Nomenclature of the American Ornithologists’ Union (AOU) maintains
the official checklist. AOU checklists are updated every few years as new information on
bird biology leads the committee members to either divide one species into two or more
species (splitting), or to group species together under one name (lumping). Changes are
often made based on new information regarding the genetics of the birds, how birds
communicate (song-types), or the frequency of hybridization. Some groups of birds have
been split and lumped several times. For instance, Dark-eyed Juncos had been split into as
many as 7 different species before being lumped together under one name (see the history of junco name changes [.pdf file]).And, members of
the titmouse family have been split from 3 species to 5 species since 1983 (see the history of name changes in titmice [.pdf file]). |
| The Oregon race of the Dark-eyed Junco, easily
distinguished by the dark "hood", winters in much of the western U.S. and in
British Columbia. Vagrants may be found across the continent. Photo by James Rockoch, Windsor, MA. |
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Tufted Titmouse is split into two species
| This year, the AOU committee has made a change of note for
FeederWatchers in Texas, where there is now a “new” species that may appear at
feeders.The American Ornithologists’ Union recently divided the Tufted Titmouse into
two distinct species. |
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The Tufted Titmouse, familiar to many FeederWatchers across eastern
North America, continues to be known by the same name. However, the race in south-central
Texas has been “split” off from the Tufted Titmouse and named the Black-crested
Titmouse. The two species look very similar, with the only obvious differences being in
the crest. The crest of the Black-crested Titmouse is indeed black, and is often raised
higher than the gray crest of the Tufted Titmouse. The change was made because scientists
have recently discovered that the two species are genetically and vocally distinct.
Despite the fact that they are now considered distinct species, they do hybridize where
they come into contact with one another along a narrow zone through east-central Texas.
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How to report titmice and juncos to FeederWatch
Texas FeederWatchers submitting data on paper forms should continue
to report Black-crested Titmouse sightings as Tufted Titmouse sightings, as the name
change was made too late for us to change our data forms prior to the 2002 – 2003
FeederWatch season. For the time being, we are labeling all titmouse reports submitted on
paper forms from Texas as “Tufted / Black-crested Titmouse” However,
FeederWatchers who submit data online may add Black-crested Titmouse to their checklist.
To do so, go to the bird checklist inside Data Entry, click on Add a Species at
the bottom of the checklist, type 'Black-crested Titmouse' in the text box, then click Show
Matches, click the check box next to the species name, then click Add the
Selected Species. The Black-crested Titmouse will now appear on your checklist.
And what about those confusing Juncos? While
the Oregon, pink-sided, white-winged, slate-colored, and gray-headed races are all
considered Dark-eyed Juncos, we’d like online FeederWatchers to report which race
is seen at your feeders. With this information, we can map the geographic distribution of
the various junco races in the winter. While the various races of juncos do not
automatically appear on the checklist of likely species found in your region, you may
easily add the various races to your list (follow the method detailed in the previous
paragraph). Learn more about the junco subspecies on the Lab's All About Birds web page .
If you submit your data on paper forms, please do not use the
write-in section of your data forms to report the different races of Dark-eyed Juncos at
your feeder. Instead, participants submitting paper data forms should continue to report
all races simply as “Dark-eyed Junco.” FeederWatchers in the southwest should
note that Yellow-eyed Juncos may visit feeders in southern Texas, Arizona, and New Mexico.
Please submit any sightings of these species on a Rare Bird Form, and use the write-in
section on your standard data forms to report Yellow-eyed Juncos.
Drawing of the various Dark-eyed
Junco races by John Schmitt. |
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