DU studies gadwall habitat

Of all the ducks that make a wintering home in Louisiana, the gadwall is one of the most popular.

However, when it comes to information about this particular bird, surprisingly little is known.

Since fall 2006, Ducks Unlimited has been conducting studies to try to change that.

"The primary objective is to gain better information on gadwall habitats," said Mike Brasher, biological team leader for the Gulf Coast joint venture. "We want to study the movement patterns and distribution of birds during the winter months.

"We then try to better relate those things to availability, and the things we believe move birds around."

To accomplish this goal, Brasher has placed tracking devices in the birds to find out how they move in the winter months.

A pilot research study was conducted during fall and winter 2006-2007 to assist with the development of a full-scale study during 2007-2009.

Researchers equipped 16 female gadwalls with backpack-mounted satellite transmitters and tracked them throughout the winter and subsequent spring migration.

The most notable was a decision to use implant satellite transmitters - those physically implanted into the abdominal cavity of captured female gadwalls - rather than backpack style transmitters, because backpack transmitters appeared to have higher than desired adverse impacts on survival rates of the radiomarked gadwalls.

The information obtained helps biologists like Brasher put together conservation strategies, which in turn allow for better conditions for ducks, meaning more ducks for hunters.

But catching ducks and planting homing devices on them is no easy task. Gadwalls spend extensive time feeding during the winter, hence habitat quality and quantity and disturbance may be important factors influencing choice of wintering areas, regional movements and over-winter survival rates, according to the Ducks Unlimited Web site.

Of the 11 birds implanted, five made it to this season.

One of those five was harvested by a hunter in Vermilion Parish this month. The duck was originally captured in Cameron Parish and had traveled all the way to Saskatchewan.

"What that nugget tells us is that there is a high degree of likelihood that these birds will return to the same wintering areas year after year, almost like with breeding sites," Brasher said.

Because gadwalls are one of the most abundant species, studying their behaviors and migrations patterns is important to every other species.

"That's why we chose to study them," Brasher said. "They're very important for conservation strategies or activities. It plays a pretty large role in what we recommend."

Essentially because there are so many gadwalls, they will receive the most attention. As DU tries to accommodate the gadwalls' patterns and behaviors, other birds will feel the effects of those recommendations.

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Information from: The Advertiser, http://www.acadiananow.com