By Ben Young
And the winner for the North American “Bird of the Decade” award is . . . the Eurasian Collared-Dove (Streptopelia decaocto). That was my determination at the turn of the decade, and I’d make a case for it three years later.
Likely no other bird species on record has stormed the North American landmass as quickly as Eurasian Collared-Doves (EUCDs). After release from captivity in the Bahamas in 1974, they arrived on the continent in the late 1970s. By the late 1980s, the bird had successfully colonized southern Florida.
Roughly a decade later, Montana had its first confirmed sighting of EUCDs in 1997. It was only a matter of time before they arrived in the Flathead Valley. First reports started coming in spring of 2007. West-northwest expansion continued into Canadian provinces up to the final frontier, Alaska, where nesting evidence of EUCDs was first recorded in 2009.
To put this feat in perspective, in the same time that it’s taken for the EUCD to spread from Florida to Alaska (quarter century), European Starlings (Sturnus vulgaris) spread from their introduced location (New York City—1890) to the Mississippi River. This is less than ½ the time it took for the House Sparrow (Passer domesticus) to complete its transcontinental expansion from its introduced location in New York City in the early 1850s.
This should come as no surprise, given the fact that the bird has had practice in the art of conquering continents. Native to the Bay of Bengal region of southern Asia, EUCDs dispersed to Turkey and the Balkans by the 16th century. Thirty years later, the species had colonized nearly every country in Western Europe.
Their mode of dispersal, referred to as jump dispersal, has proved incredibly efficient, making them one of the most successful terrestrial invaders. Small populations of birds move up to several hundred miles ahead of the known range, only to colonize the area between as local populations expand.
A major factor contributing to the success of EUCDs is their high affinity for human-influenced landscapes such as gardens, town parks, pasture land, and other features that provide year-round access to seed sources, roosts, and nesting sites.
Three key questions appear to dominate much of the current research involving EUCDs. First is the mystery surrounding the expansion pattern of this bird in both its North American and European transcontinental movements. In both cases, birds expanded with a northwest trajectory, leaving regions due north of the original populations relatively devoid of established populations. For example, while observations of EUCDs have occurred in the New England states, a bona fide expansion up the eastern seaboard has yet to occur beyond the Carolinas.
Secondly, researchers are monitoring the potential impacts of the invasive EUCDs on the displacement of native avifauna, like the Mourning Dove (Zenaida macroura), by competitive exclusion. To date there exists no conclusive evidence that this is occurring. Rather, studies suggest that impacts of EUCDs on Mourning Doves may be less significant than suspected, as aggression toward and competition with Mourning Doves do not appear to be limiting factors (Poling & Hayslette 2006; Hayslette 2006). Curiously, one study even observed an increase in the site-level abundance of other dove species at sampling locations where EUCDs also increased in abundance (Bonter, Zuckerberg, & Dickinson 2010).
A third research focus is the role which EUCDs play in the transmission of emerging infectious diseases like pigeon paramyxovirus (PPMV). In December 2009 and January 2010, ill and dead EUCDs were observed in Three Forks and Belgrade, Montana. Montana Fish, Wildlife, and Parks collected six individual birds to submit for diagnostic testing. The cause of death in each of the examined birds was infection with PPMV, a virus for which 236 species of free-ranging birds (wild, domestic, and pets) are known to be susceptible.
If you’d like to find a EUCD, chances are that unless you live in a heavily forested area, they are already present. If you have Mourning Doves coming to your feeder, take a closer look for the larger-bodied EUCD. Nearly twice the size by mass of a Mourning Dove (200 g vs. 120 g), EUCDs are also distinguished from Mourning Doves by their broad, squared-off tail, more rounded dark-tipped wings, and thin black collar on the nape of the neck. Check for them on exposed perches like utility poles and wires from which they offer their three-syllable coo. Or drive past some of Kalispell’s city parks and neighborhoods with mature spruce trees, where they roost and nest.
• Bonter, D. N., Zuckerberg, B., & Dickinson, J. L. (2010). Invasive birds in a novel landscape: habitat associations and effects on established species. Ecography, 33(3), 494-502. doi:10.1111/j.1600-0587.2009.06017.x
• Eurasian Collared-Dove – Cornell Lab of Ornithology. (n.d.). All About Birds. Retrieved August 12, 2013, from http://www.allaboutbirds.org/guide/eurasian_collared-dove/lifehistory
• FUJISAKI, I., PEARLSTINE, E. V., & MAZZOTTI, F. J. (2010). The rapid spread of invasive Eurasian Collared Doves Streptopelia decaocto in the continental USA follows human-altered habitats. Ibis, 152(3), 622-632. doi:10.1111/j.1474-919X.2010.01038.x
• Hayslette, S. E. (2006). SEED-SIZE SELECTION IN MOURNING DOVES AND EURASIAN COLLARED-DOVES. Wilson Journal Of Ornithology, 118(1), 64-69.
• Johnson, S. A., & Donaldson-Fortier, G. (2012). Florida’s Introduced Birds: Eurasian Collared-Dove (Streptopelia decaocto). EDIS: University of Florida IFAS Extension. Online: http://edis.ifas.ufl.edu/uw301
• Poling, T. D., & Hayslette, S. E. (2006). Dietary Overlap and Foraging Competition Between Mourning Doves and Eurasian Collared-Doves. Journal Of Wildlife Management, 70(4), 996-1004.
• Romagosa, Christina Margarita. 2012. Eurasian Collared-Dove (Streptopelia decaocto), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/630
• Schuler, K., Green, D., Justice-Allen, A., Jaffe, R., Cunningham, M., Thomas, N., & … Ip, H. (2012). Expansion of an Exotic Species and Concomitant Disease Outbreaks: Pigeon Paramyxovirus in Free-Ranging Eurasian Collared Doves. Ecohealth, 9(2), 163-170. doi:10.1007/s10393-012-0758