It's not often that a new bird becomes established in the Rogue Valley. There have been few in the last 30 years. The barred owl has made its way slowly down from Canada. Their numbers in Jackson County are not large, but they are causing concern because of their interactions with spotted owls. Northern mockingbirds have established a modest breeding population after working their way north from California.

It's not often that a new bird becomes established in the Rogue Valley. There have been few in the last 30 years. The barred owl has made its way slowly down from Canada. Their numbers in Jackson County are not large, but they are causing concern because of their interactions with spotted owls. Northern mockingbirds have established a modest breeding population after working their way north from California.

The latest immigrant has not entered the valley meekly. The Eurasian collared dove has exploded into the valley. Several years ago I first met the collared dove in Florida, where it had made its way in the 1980s after escaping as a cage bird in the Bahamas. People warned me that it was headed our way and fast. Already it was spreading rapidly throughout the southeastern states. About six years ago, scattered birds were seen in places around Oregon, and a few individuals set up residence in White City. Birders throughout the region made the pilgrimage to see these novel birds.

A collared dove is a bit larger than our native mourning dove. It has a narrow black collar and a square tail with much white, unlike the pointed tail of a mourning dove.

As of this spring they are breeding in more than a dozen neighborhoods around the county from Phoenix to Medford to Central Point to Sam's Valley and even Shady Cove. Some people have more than 20 birds visiting their feeders. I have yet to hear of them in Ashland, but it won't be long.

What are we to make of this new arrival? Unlike the barred owl and mockingbird that are natives responding to some change in their environment, the dove was introduced. Should we greet the doves warmly, or should we be concerned and fight off the invader? With introduced species it's difficult to tell until it's too late. Some immigrants are innocuous while others become "invasive species." The term indicates an alien that is disruptive to native communities.

House sparrows qualify as an invasive species and have caused a decline in swallow populations and other species. Likewise, European starlings have hurt western bluebird populations. Both compete with our native birds for nesting sites and will even destroy the eggs and kill the young of others.

Even the wild turkey has had a negative impact upon our native wildlife. Turkeys have a taste for lizards and small snakes and depress their populations. Other invasive species like the bullfrog, Himalaya blackberry, and the fungus, phytophthora, have been ecological disasters.

Collared doves may have less impact than some because of their close association with people. If they remain in cities and backyards like the rock pigeon, they may make polite neighbors. However, if they spread beyond the bird baths and feeders of people's backyards, they may prove unwelcome in ways we can't imagine yet.

Regardless, collared doves are coming and in force. About all we can do is to enjoy them and hope for the best, but there is an important lesson here. Avoiding the introduction of a potentially invasive species is far easier than eliminating one once it has become established. The state of Jefferson supports a unique and diverse natural heritage, and we would be wise to be vigilant and offer it our best protection.

Stewart Janes is a biology professor at Southern Oregon University. He can be reached at janes@sou.edu.