Study uses GPS to determine nesting sites mottled ducks like

MORGAN CITY, La.—A Louisiana State University doctoral student is hoping solar-powered GPS transmitters help her track down what sort of territory mottled ducks prefer for their nests.

Populations of these puddle ducks are declining along much of the upper Texas coastline, apparently due to habitat loss, but very little is known about what’s best for their nests, Elizabeth Bonczek told The Daily Review.

She and state wildlife biologists went out into Rockefeller Wildlife Refuge while Hurricane Harvey was in the western Gulf to get transmitters onto the ducks, which are related to mallards. Male and female mottled ducks look a bit like female mallards, but their heads and necks are tan rather than dark brown.

Studies in the early 1980s also focused on the Rockefeller refuge but got little good information because it is hard to find those nests out in southwest Louisiana’s vast marshes, Bonczek said.

The GPS transmitters are much more accurate than the radio transmitters previously used to track the ducks. They can locate something within 30 meters, while the VHF radio is accurate only to about 1 kilometer.

Bonczek says her study will look at how the type of landscape is related to nest site, nesting success, adult survival, and females’ likelihood of breeding.

She and teams from the Department of Wildlife and Fisheries went out to catch ducks in late August because that’s when they molt, losing feathers they need to fly. They went out after dark, using airboats and hand-held lights.

Every bird was banded but only the biggest and healthiest got transmitters, to make sure they could handle the extra weight of 16 to 18 grams (about six-tenths of an ounce).

She says she had her target— transmitters on 65 ducks—in two nights.

The transmitters cost $1,700 each. In addition to Wildlife and Fisheries, Ducks Unlimited, Gulf Coast Joint Venture and the LSU School of Renewable Resources helped with money and logistics.