As I write this in late July, a pair of Eurasian collared doves are calling in my backyard. They've raised a family in the trees behind my house this summer, even at the relatively high elevation where I live (7700 ft/2347 meters). As their name indicates, Eurasian collared doves are from Europe and Asia, not the New World. In fact, they're a recent arrival here in Colorado. We used to see and hear the native mourning doves all the time in my area, but alas no more.
Eurasian collared dove. (That's not me feeding them!) Note the black collar on its neck.
Photo by Rovdyr via Wikimedia Commons.
How did it get here? Collared doves have traditionally been kept as pets. In 1974, a pet shop in the Bahamas was burglarized, setting some collared doves free. Afterwards, the shop owner set free all 50 remaining birds (why?). Then on the Caribbean island of Guadalupe, more collared doves were set free when a volcanic eruption was imminent. From those two places the doves made their way to Florida and proceeded to take over North America.
No bird species had conquered North America with the speed of the Eurasian collared dove. Now, just 50 years later, the collared dove lives in every state in the Lower 48, as well as parts of Canada and northern Mexico. The bird is classified as an invasive species. It's not yet clear what effect collared doves are having on native birds, but they are known to be an aggressive competitor. I've been a birdwatcher for over thirty years and can tell you that I used to commonly see and hear mourning doves April through October (they migrate to warmer climates in the winter). Now I don't. I haven't seen a mourning dove in years. But the collared doves stay year 'round.
The similar-looking American mourning dove. It has no collar.
Photo by Showmanradio via Wikimedia Commons.
The release of Eurasian collared doves is a cautionary tale when working against Mother Nature. Hopefully it won't have a negative impact on native doves, but it might give a hit to native species in the same way the European Starling and House Sparrow (both from Europe) have. We're watching an experiment in real time, showing us what happens when a nonnative species is let loose in an new environment where it has the capacity to take over and out-muscle native species. Only time will tell how this saga plays out.
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