Wild Cam: Harvest may contribute to shorebird decline

In the coastal areas of Guyana, hunters get creative when trapping birds—sometimes “shocking” whole flocks with wires. Tying a 12-meter wire to a pole and laying it down in a straight line in the mud, teams work to flush birds toward the trap. Once their quarry crosses the wire, a harvester will pull the line taut so it strikes the bird in flight, killing or stunning it long enough for capture.

They’re even inventive when it comes to where to get the wires. “In the past, they melted down radial tires and took the wire out,” said Brad Andres, National coordinator of the U.S. Shorebird partnership with the U.S. Fish and Wildlife Service. “[The hunting method] is pretty indiscriminate.”

According to ongoing research, legally harvesting birds in Guyana using methods like the one described contributes to the removal of tens of thousands of shorebirds—some considered threatened or species of concern in North America.

“We have a good idea that the harvest is pretty substantial,” Andres said.

Shorebirds have declined by about 40% across North America since 1970, despite receiving protection in Canada and the United States through the Migratory Bird Treaty, said Amelia Cox, a quantitative biologist with the Canadian Wildlife Service who works with the migratory bird management program. Through this treaty, the U.S. enacted the Migratory Bird Treaty Act and Canada enacted the Migratory Birds Convention Act, both of which prohibit most seabird harvest.

But many of these North American bird species spend considerable time outside of these two countries. Some spend their winters in warmer climates in Caribbean Islands and the Caribbean coast of South America, where they are not protected.

Researchers have been tracking how many birds are being taken in French overseas territories like Martinique, Guadalupe and French Guiana, but they were unclear about harvest numbers in Guyana. In research presented at The Wildlife Society’s virtual 2021 Annual Conference, Cox and her colleagues described their findings about harvest numbers in Guyana.

“Guyana had really been one of those gaps where we didn’t know much of what was going on,” said, Andres, who worked with Cox on the research.

From August to November in 2020, Andres and Cox worked with Leon Moore, a local conservationist and bird tour leader in Guyana, to survey locals involved in the harvest and trade of shorebirds, whether it was people shocking the birds themselves or market vendors who sold the resulting bushmeat, like that shown in the photograph above.

They found 13 different species were harvested. About 90% of the harvested species were small shorebirds, including species like semipalmated plovers (Charadrius semipalmatus), semipalmated sandpipers (Calidris pusilla) and white-rumped sandpipers (Calidris fuscicollis).

The most harvested large shorebirds were lesser yellowlegs (Tringa flavipes), considered threatened by the Committee on the Status of Endangered Wildlife in Canada. These birds spend their summers breeding in the Boreal Forest of Alaska eastward through Canada to just past the border of Quebec and Ontario. They migrate southward during the colder months.

The researchers estimated that at the two sites they surveyed, between 17,000 and 38,000 birds were harvested in the month of September—the month the largest number of shorebirds are in Guyana. They estimated an additional 8,000 of these birds were sold at the market every year, from August when the migrants begin to arrive until the beginning of November when they have mostly all flown eastward and southward for the boreal winter.

“The beach harvest is seasonal,” Cox said.

Andres cautions that these numbers are preliminary, particularly since they haven’t gotten a good handle on many other sites where harvest occurs. People there might be selling harvested birds directly to restaurants, or using them for personal consumption.

Even though the work is far from complete—researchers still don’t have any idea of the numbers of shorebirds harvested in Venezuela, for example—Cox said that it’s likely that harvest combined with climate change, habitat loss and other factors likely contributes to population declines.

As far as yellowlegs are concerned, Andres said that harvest in the Caribbean likely contributes to at least local declines in the eastern populations that breed around James and Hudson Bay in Canada. “We could be driving these local populations down,” he said, adding that so far, it appears not many shorebirds are harvested on the Pacific Coast of South America.

This photo essay is part of an occasional series from The Wildlife Society featuring photos and video images of wildlife taken with camera traps and other equipment. Check out other entries in the series here. If you’re working on an interesting camera trap research project or one that has a series of good photos you’d like to share, email Josh at jlearn@wildlife.org.

Header Image: Many shorebird species migrate between northern North America and the Caribbean coast of South America. Credit: Leon Moore