A burglary in the Bahamas and the threat of a volcano eruption on the island of Guadeloupe set in motion one of the fastest and most widespread invasions of a non-native wildlife species — a bird, in this case — witnessed in North America.
Effects on the continent’s native wildlife resulting from those two seemingly unrelated events barely 40 years ago remain unclear. But Texas dove hunters certainly have benefited. This dove season, which began Sept. 1, Texas’ 300,000 wingshooters will take more than a half-million Eurasian collared doves, a bird that didn’t exist in the state — or most of North America — just a quarter century ago but has a wild population now numbering about 5 million in the Lone Star State.
“They have turned out to be incredibly adaptable and prolific,” Owen Fitzsimmons, Texas Parks and Wildlife Department’s dove program director, understated in talking about the non-native collared doves that now live, nest and reproduce across the whole of this sprawling ecologically diverse state.
They also have turned out to be an unexpected but welcome bonus for the state’s wingshooters. Collared doves, with some exceptions, generally inhabit the same habitat as mourning doves and white-winged doves, the state’s most populous game birds. They also behave, fly and taste much like a larger version of those native doves, making them just as challenging and popular with Texas wingshooters. And because they are non-natives and an invasive species, collared doves are not classified as game birds, which allows unlimited take of the prolific aliens.
The first collared doves documented in Texas were seen in the northeast corner of the state in the mid-1990s. Their arrival was the then-latest frontier the birds colonized in what was becoming a fast-spreading invasion with roots in seemingly unrelated events in the Caribbean in the mid-1970s.
In 1974, burglars broke into a pet business in the Bahamas that dealt in exotic birds. The criminals opened a cage holding an estimated 50 Eurasian collared doves, and the flock went free.
Two years later, the owner of a captive flock of collared doves on the Caribbean island of Guadeloupe let loose those birds before fleeing the predicted eruption of the island’s La Soufriere volcano.
Soon after, the first wild collared doves documented in North America appeared in South Florida. Those birds, experts including those at the universally respected Cornell University Lab of Ornithology deduce, originated from those two freed flocks.
This was just the latest beachhead in the species’ long history of invasion and colonization.
Eurasian collared doves are native to the Bay of Bengal region of the Indian subcontinent. In the 1600s, traders brought them to the Middle East and Turkey, where they thrived. From there, they slowly spread west and north until, by the 1950s, they had colonized most of Europe.
The bird’s spread in the Americas has been much faster and prodigious.
From Florida, the birds marched — flew — north, south and west. Within only a few years of their arrival in northeast Texas in the 1990s, they had colonized the entire state and far beyond.
By 2004, Texas held what state wildlife officials then roughly estimated were “several hundred thousand” collared doves. They didn’t really have a solid figure as the birds were just popping up everywhere and the agency had no system in place to census the non-native species. But it was clear the birds were thriving in Texas.
Just slightly smaller than native white-winged doves and half the size of native mourning doves, collared doves are easily distinguished from their close relatives by their size and pale-gray coloring and the distinctive black slash on the nape of their neck that gives them their common name. They can be identified in flight by their larger size, generally slower wingbeat and their “square” tail feathering; mourning doves and whitewings have “pointed” tails.
Collared doves share many behaviors with their native relatives, including their preference for feeding on seeds — agricultural and native — in areas with low or little ground cover. It is not uncommon to see both mourning doves and collared doves feeding in the same field. Less common is to see collared doves mixed with whitewings on feeding fields. But whitewings and collared doves certainly share a trait of being comfortable nesting and roosting around human development.
“They’re a bird that does really well in suburban and some rural areas,” Fitzsimmons said, noting that collared doves, like whitewings, benefit from the expansive nesting habitat created by the large number of mature trees in urban and suburban areas and the abundance of water and forage in those settings.
Back yards beckon
Collared doves quickly find and take advantage of the millions of bird feeders in yards across Texas.
They also are especially attracted to some rural areas, particularly those around farming and ranching operations. Barns, grain storage silos and elevators, and livestock feedlots serve as larders and lodging for the Eurasian colonizers.
“Some of the biggest concentrations of collared doves in Texas are in rural areas, especially in the Panhandle around grain elevators and feedlots,” Fitzsimmons said.
That adaptability to varied habitat gives collared doves a scaly pink leg up on their native cousins.
Also to their advantage, collared doves are amazingly fecund creatures. Just as with native mourning and whitewing doves, a pair of collared doves construct a seemingly flimsy nest onto which a pair of eggs are laid. All three species are serial nesters, often making multiple nesting attempts each year. But collared doves take it to an extreme. Mourning doves and whitewings may make two or maybe three nesting attempts a year. Collared doves regularly make four nesting attempts a year and even more. Often, collared doves will begin constructing their next nest while they still have fledglings in an earlier nest.
“There’s documentation of collared doves nesting as many as six times in one year,” Fitzsimmons said.
That robust reproduction coupled with adaptability and wanderlust has seen collared doves expand their number and range in startling fashion. In less than 40 years of their arrival in North America, they had spread south to Panama, across almost the entirety of North America, including all of the contiguous United States, into southern Canada and even into Alaska. Collared doves were first documented near Fairbanks, Alaska, in 2014, where the birds spent the winter and survived.
That behavior — staying in a cold, often frozen region instead of migrating to warmer areas — appears one way collared doves differ from native doves. While mourning and whitewing doves make migratory moves to the south in autumn and winter, returning north in spring and summer, collared doves appear to forgo such annual long-distance movements. The birds appear to simply shift locations within a fairly limited region, moving only far enough to find food and suitable habitat.
Since the birds’ arrival and subsequent boom, wildlife managers have launched research and monitoring efforts to try quantifying the population and qualifying their impact or potential impact on native species. So far, that impact appears minimal. While the non-native collared doves share some habitat with native doves and obviously compete for resources, no significant detrimental effects have been discovered.
There is concern that the non-native collared doves could prove to carry and transmit Trichomonas, a the virulent avian virus or other transmissible viruses or diseases, Fitzsimmons said.
“It’s something we’re watching,” he said.
A bonus of sorts
While the ecological impact of collard doves remains unsettled, their benefit to Texas wingshooters isn’t. The birds have become a player in the state’s hunting community.
Because collared doves are a non-native species, they do not fall under the Migratory Bird Treaty Act, the federal law that regulates hunting of native migratory birds such as mourning and white-winged doves. Similarly, Texas state law does not classify the alien doves as game birds and their taking is not regulated. In Texas, collared doves can be legally hunted at any time and taken in any number, the same as their close cousins, feral rock doves (pigeons).
This liberal loophole allows licensed Texas hunters the latitude to take collared doves when the opportunity presents itself. Over the last several years, some hunters, especially in the Panhandle, have taken to year-round hunting of collared doves, focusing on the feedlots and other area where the big doves concentrate.
“There are even some outfitters and guides now offering collared dove hunts,” Fitzsimmons said.
But most collared doves are taken incidentally by Texas wingshooters targeting mourning or whitewing doves during the autumn hunting seasons for those birds. The collared doves are “bonus” birds for dove hunters. While the daily aggregate bag limit of mourning and whitewing during Texas general dove season is 15 birds, there is no limit on the number of collared doves that hunters can take and those collared doves do not count as part of the 15-dove daily limit.
Part of the landscape
To prevent potential issues concerning identification of the unprotected collared doves and closely regulated native doves, hunters taking collared doves are advised to not clean the birds before getting home or at least leaving a fully feathered wing on all doves so game wardens can easily identify the species.
Those collared doves are welcomed by most dove hunters, who find them just as challenging a target as the native doves and equally wonderful on the plate. And they take a lot of them.
“We estimate the annual harvest of Eurasian collared doves in Texas is now 700,000 to 800,000,” Fitzsimmons said. That’s not nearly as many as the 3 million whitewings and 5 million mourning doves that Texas hunters annual take. But it’s far from insignificant.
“They are a part of dove hunting, now, for a lot of Texas hunters,” Fitzsimmons said.
For that, Texas wingshooters can thank burglars and a volcano.
About Pigeon Patrol:
Pigeon Patrol Products & Services is the leading manufacturer and distributor of bird deterrent (control) products in Canada. Pigeon Patrol products have solved pest bird problems in industrial, commercial, and residential settings since 2000, by using safe and humane bird deterrents with only bird and animal friendly solutions. At Pigeon Patrol, we manufacture and offer a variety of bird deterrents, ranging from Ultra-flex Bird Spikes with UV protection, Bird Netting, 4-S Gel and the best Ultrasonic and audible sound devices on the market today.
Voted Best Canadian wholesaler for Bird Deterrent products four years in a row.
Contact Info: 1- 877– 4– NO-BIRD (www.pigeonpatrol.ca)