Back in 1974 a local pigeon fancier imported a flock of about 50 Eurasian collared-doves to the Bahamas. Ultimately he released the birds, and they took to life in the West Indies.
By the late 1970s some had reached south Florida, and by the late 1980s, some had been seen in Georgia and Arkansas. Since then biologists and birders have reported collared-doves in Alabama (1991), Texas (1995), South Dakota (1996), Montana (1997), Minnesota (1998), Iowa (1999) and Oregon (1999).
Today collared doves occur all across the U.S., though for some reason their numbers are small in the mid-Atlantic and northeastern states. Though the rapid expansion of collared-dove populations has been impressive, it is neither unprecedented nor entirely natural.
Originally native to the Indian subcontinent, Eurasian collared-doves began to wander northwestward into Asia and Europe in the 1600s. By the 1930s collared doves began a rapid range expansion in Europe. It is not known if these movements were natural or facilitated by man. They reached Germany by 1945 and Great Britain in 1955, when four birds were counted.
By 1970 the population in Great Britain had increased to approximately 20,000 pairs. Though Eurasian collared-doves do not migrate, the birds disperse when local populations begin to grow. This may help explain their ability to rapidly expand their range. Furthermore, they seem genetically predisposed to move in a northwesterly direction when dispersing. This may explain why so few collared doves are seen in northeastern states.
Since the 1970s, many additional intentional and accidental releases have occurred in California, Colorado, Missouri, Tennessee, Texas, and throughout the Caribbean.
Thrive in human areas
Collared-doves visit bird feeders for sunflower seeds, millet, and various cereal grains, and seem to do best in areas with higher human populations. In some places collared doves have become relatively common backyard birds. The availability of backyard bird feeders is certainly one factor that has helped fuel their range expansion in North America. It seems inevitable that collared-doves will continue to expand their range and become increasingly common.
When exotic species invade new areas, a major conservation concern is the impact the invader may have on native species. In this case, biologists worry that mourning doves may be negatively affected. And in some towns and cities collared doves have displaced mourning doves.
In more rural areas, mourning doves hold their own. Regulations vary from state to state, but often species that are classified as “exotic” get no protection and can be killed at will. House sparrows and European starlings are examples of unprotected exotic species. The concern is that if collared doves are designated as an unprotected exotic species, native mourning doves might be killed by mistake or out of season.
In West Virginia all members of the dove/pigeon family (Columbidae) are classified as game birds and subject to hunting regulations. So invading doves of any species are immediately subject to existing laws.
Earlier this year the Pennsylvania Game Commission took a different approach. To protect native mourning doves, the Game Commission classified the Eurasian collared-dove as a game bird for hunters possessing a general hunting license and a migratory bird license. They must be counted as part of the bag limit for mourning doves.
The rationale is that if collared-doves had been classified as an exotic species, they could be taken year-round and that could lead to out-of-season kills of mourning doves.
The intent is to insure that mourning doves not be killed by mistake or out of season. Some states have simply offered collared doves no protection – no closed season and no bag limits. It will be interesting to see how mourning doves fare in states where collared doves are totally unprotected. Compounding the problem is that collared doves and mourning doves can be tricky to identify, especially on the wing.
Collared doves are larger (7 oz. vs. 4 oz.), and their tails are square rather than pointed. And of course, collared-doves have a distinctive black band across the back of the neck. Dove hunters should get to know the new species they may encounter this fall, and birders can add a new target species to their life list.