Goose camp: Tracking troubled birds

Date:April 28, 2016

Source:University of Delaware

Summary:A research team is studying the Atlantic brant goose in Canada’s Hudson Bay region. The bird's population has been on a moderate decline, and the team is looking to seen if limitations during the summer breeding season have accelerated that trend.

When the University of Delaware's Chris Williams traveled to Southampton Island in Canada's north Hudson Bay in the summer of 2015 to study the nesting sites of the Atlantic brant goose, the last thing he and his research group expected to run into was a fellow Mid-Atlantic resident. But as he scoured the scenery one day, he found someone else who made the trip in the form of a red knot.

Red knots are shorebirds that come north through the Delaware Bay on their trip from South America to the Arctic, eating horseshoe crabs to refuel on their trip.

Williams said he was pleased to get a photograph of the bird, which had a leg flag markings J7V that was last re-sighted in 2010 and 2011 around Cape May, New Jersey.

"It was fantastic to run into this little bird that had made the long trip north just like us," said Williams, associate professor of wildlife ecology who oversees a Waterfowl and Upland Gamebird research program in UD's College of Agriculture and Natural Resources.

Brant in decline

The focus of the research team, which includes UD graduate student Clark Nissley, was on the Atlantic brant goose, a bird whose population has been fluctuating and on a moderate decline for many years, to learn if limitations during the summer breeding season have accelerated that trend.

The brant has a number of factors working against it, beginning with its size. Because the brant is smaller than the other two birds that nest in the area -- snow geese and cackling geese -- it is at a disadvantage when competing for habitat and food.

Also due to its size disadvantage, the brant arrives at its breeding grounds later than the other geese, which can build up larger fat reserves prior to make the trip north, enabling them to make fewer stops to the Arctic nesting grounds. The smaller brant, on the other hand, must stop more along the way in order to feed and rebuild its fat stores. Because of these delays, the brant arrive about 1-2 weeks after lesser snow geese and cackling geese causing them to miss out on prime nesting real estate.

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