No Turtledoves for Christmas?

The birds face a catastrophic decline because of industrial agriculture. One new idea: Pay farmers to plant dove-friendly crops.
(Photo: Mike Powles/Getty Images)
Dec 18, 2014· 2 MIN READ
John R. Platt covers the environment, wildlife, and technology and for TakePart, Scientific American, Audubon, and other publications.

Can you sing “The Twelve Days of Christmas” without two turtledoves? Well, that just might be the future of the holiday classic. Populations of the iconic birds have plummeted in the past few decades, falling 77 percent in Europe since 1980 and 96 percent in the United Kingdom since 1970.

The turtledoves’ decline stems from a change in their diet, or more specifically the food that became available to them starting in the 1950s and ’60s. That’s when industrialized farming took hold in the U.K. and crowded out native plants such as fumitory and chickweed, which the birds relied on.

“As farming efficiency has increased, more herbicides have been used, and the availability of these non-cropped plants in the wider landscape has declined,” said Jenny Dunn, conservation scientist with the Royal Society for the Protection of Birds (RSPB), who has been studying turtledoves since 2010.

The farmed crops are also much denser than natural vegetation, which doesn’t provide ideal conditions for turtledoves when they nest or search for food. “They tend to choose habitats with a fairly open structure and quite a bit of bare ground,” Dunn said.

The birds also face an additional threat: A protozoan parasite called Trichomonas gallinae, which can cause lesions in the throat and gullet and can be fatal. Tests by Dunn and her colleagues found the parasite on 95 percent of sampled turtledoves in the East Anglia region of the U.K. “This compares to around 50 percent of other U.K. dove and pigeon species, such as wood pigeons and stock doves,” she said.

To help solve all of these problems and give the turtledoves a needed boost, Dunn and fellow researchers from the RSPB and the University of Leeds have been studying ways to reduce both the shortage of food and the excess of disease.

That includes trials of seed-rich plots on farms across East Anglia. “The farmers we’ve worked with throughout this research have all been very positive about the idea,” Dunn said. “Turtledoves are such an iconic bird, and people notice if they’re not around. The idea that there might be something they can do to directly benefit these birds has generally had a very positive reaction.”

The farmers actually get an incentive to replant a small portion of their land. Under the U.K.’s Higher Level Stewardship Scheme, farmers can receive payments for making some of their properties more hospitable to wildlife. In this case, the farmers take the portion of their land devoted to nectar flowers—which are intended to attract pollinators—and switch it over to a trial mix of plants designed by Dunn and her colleagues.

“We’re trying to provide a range of seed-producing plants that start seeding early in the year and continue seeding throughout the summer within a patchy vegetation structure, so that there’s space for the birds to land and access the seed,” she said.

Early results show promise. Although it’s too soon to know if turtledove breeding has increased, Dunn reports that pollinator numbers have stayed the same on these plots, meaning they serve the same role for farmers as the previous nectar-based plantings.

The researchers still hope to discover the exact mix of seeds and plants that will best serve turtledoves’ needs. Part of that requires studying the birds’ droppings to see what they eat. “When this project started in 2010, the only way to tell what birds had been eating was to look at seed husks that remained in their feces through the microscope,” Dunn said.

Technology has advanced since then: Now the researchers can learn even more by studying the leftover DNA present within the droppings. That DNA residue would reveal any foods, such as sunflower hearts, that don’t leave a husk behind. The research team has launched a crowdfunding campaign to help them accomplish this next stage of their investigation. They hope to raise about $7,800 by Jan. 23.

Dunn said they can do some of the work without the crowdfunding dollars, but the extra boost will allow them to learn much more. “It’s really important that we know what the birds are feeding on, and what they’re feeding their chicks,” she said. “This allows us to see whether they’re using the trial seed plots, what other habitats they may be using for foraging, how much they may be relying on anthropogenic sources of food such as those put out at bird feeders, and whether chick diet might influence growth rates or the chances of them fledging successfully.” That could be the key to increasing breeding populations.

Although turtledoves have almost disappeared from the British Isles, they remain one of the most iconic birds in the region. “Whilst the analysis of fecal samples isn’t exactly ‘sexy,’ we’re hoping that the public will get behind us,” Dunn said.

Without that help, turtledoves may become rarer than a partridge in a pear tree.