Geography Reference
In-Depth Information
When noisy miners, black redstarts, and Bewick's wrens displace other
native species, I am concerned but take some consolation in the fact that these
aggressive and successful species too are natives. Unfortunately, interactions
with nonnative species pose a much more serious risk to biological diversity.
Nonnative predators have decimated island bird communities around the
globe. Nonnative competitors are common in plant and invertebrate commu-
nities where they are a major factor in recent extinctions. Such competitors
seem to pose less of a problem to birds. Black drongos may challenge some
birds of Micronesia; barred owls obliterate spotted owls. But in general, I
think that the many parrots, mynas, upland game birds, and songbirds that
have been introduced around the world coexist with natives as benign or even
benei cial partners, especially in food-rich urban areas. An exotic dove, how-
ever, is changing my mind.
Eurasian collared doves exploit cities and towns throughout their native
ranges in Asia and Europe. Since their invasion of Florida in the early 1980s,
they have been well along the way to doing the same in the United States.
This nonnative pigeon of moderate size is well distributed across the south-
ern states and is moving north. A small number of them even live in Seattle's
subdivisions and neighboring towns, as far as one can get in the continental
United States from Florida. Recently, they've been spotted even in Alaska.
Several native doves coexist in the southern United States, raising concerns
about whether there is room and food enough for one more.
In Socorro, New Mexico, high in the Chihuahuan Desert, mourning
doves were a common suburban bird twenty years ago. That was before larger
white-winged doves expanded their ranges northward and began breeding in
Socorro. With the arrival of the white-wings, mourning doves shifted their
distribution from residential areas to the surrounding desert. Inca doves,
which are small ground-feeding birds, also moved north and into Socorro's
residential area at this time. In some places one could i nd all three doves co-
existing, but by 2006 most residential areas held only Inca and white-winged
 
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