Maritime birds find sanctuary on dredge spoil island

By Peter Vankevich

If you have taken the Ocracoke-Swan Quarter ferry, you may have noticed a small island about one mile from Ocracoke village.

This is Big Foot Island, created from dredge deposits of sand. Dredge spoil islands provide attractive nesting habitat for coastal birds. They are often free of predators such as cats, mink and raccoons and do not have human activity. On the other hand, these islands often lack the foraging resources available to birds nesting in bigger habitats. The already crowded Big Foot became more so with the addition of a new species. “

The first record of pelicans nesting (54) on Big Foot Island was in 2014, and in 2015, hundreds are nesting there,” said Sarah Schweitzer, water bird investigations and management project leader of the N.C. Wildlife Resources Commission.  This year, the pelicans abandoned several nearby islands where they had been nesting.

“We don’t know for sure that Big Foot picked up most or all of the refugees, but we assume it,” said John Weske, a biologist of Sandy Spring, Md., who has been banding birds on the island for many years. The reason for this major shift is not a fluke.

Last year, Hurricane Arthur, a category two storm that struck the area on July 4, severely impacted the nesting success of many birds in its path, especially on low-lying islands near Portsmouth. These islands–Beacon, Shell Castle, and North Rock–were once good for nesting island pelicans and several other species, including American oystercatchers. As those islands have dwindled due to erosion, they are more subject to over wash from storms and full-moon tides that adversely affect successful nesting.

This year, no pelicans nested on those islands. According to Lindsay Addison, coastal biologist for Audubon North Carolina which

manages the low-lying Beacon, Shell Castle, and North Rock islands, even though the pelicans did not nest, the islands were far from a bird wasteland. American oystercatchers, black skimmers, Forster’s, common and royal terns, great black-backed and herring gulls, great egrets and tricolored herons are some of the species that nested.

Since Big Foot is relatively high and thus safer from extensive over wash, it did not suffer the major bird casualties from Arthur last year that the other islands and South Point suffered. According to Schweitzer, many of the terns had already fledged which helped with their survival, but many of the young pelicans were washed away.

Some made it to Ocracoke and were safely rescued, thanks to the efforts of the island’s wildlife rehabilitator, Elizabeth Hanrahan, who assisted in getting them to rehab centers. All but one survived and were released. These colonial nesting birds (meaning they live in colonies, not as solitary pairs) are carefully monitored to count the numbers, which helps track whether the bird populations are stable, increasing or in decline.

An important part of this research includes banding, and young birds have a small numeric band clipped to their right leg.

On Big Foot, royal and Sandwich terns and, now, brown pelicans are banded as part of a federally funded banding program out of the Bird Banding Laboratory (a unit within the Biological Resources Division of the U.S. Geological Survey) in Laurel, Md.

Every year in the early summer, the project co-leaders Weske and Micou M. Browne of Raleigh recruit volunteers to herd the young birds into a temporary pen where they can be banded and released in the least disruptive manner. While identifying a young pelican is easy, there are subtle differences with young royal and Sandwich terns which require some identification skills.

Each species has a particular numeric band to be used. Banding occurs two or more times per season, several weeks apart. This is important for pelicans since their nesting season can be several weeks longer than that of terns.

While the final results have not been compiled, all indications are that this season will be a major success. In addition to the 54 nests for brown pelicans, in 2014, there were 7,206 royal tern nests and 1,577 nests for Sandwich terns. Those numbers should be stable.

As a word of caution, kayakers and boaters should not stress the young birds on these islands as that can jeopardize their survival. The chicks will hide in the wrack (dead matted marine vegetation) and wait for their parents to bring them food. When frightened they will stay still and due to their concealment can inadvertently be stepped on.