The end of advanced-placement testing is not the end of classwork for the AP biology class at Ledyard High School. Instead, they got on a Project Oceanology boat first thing in the morning on May 24 to continue a longstanding research project looking at bird populations on islands in Long Island Sound.

Every year, the AP biology class visits South Dumpling Island, just over the border in New York, to investigate the impact of cormorants and gulls on the island and each other. This year, the class also visited Sandy Point, an island that straddles the Connecticut/Rhode Island border, to look at nests there.

Adam Crawford and Haley Nash-Thompson, two of the 14 students who went on the excursion, said the field trip was a lot different than others they had been on. Instead of watching or listening to other people conduct research, they were actively counting nests and eggs.

Students donned hard hats and armed themselves with sticks to protect themselves from birds and droppings, though Ben Vajdos said he was an easy target for attacks because of his height, and Ebony Haywood said she got hit twice with guano.

Gulls are very territorial, and students said they were told by the Project O staff that they would eat unattended eggs and chicks. A few were able to pick up gull chicks from their nests, as long as they put them back and moved away before the parents noticed.

David Bednarz, biology teacher at Ledyard High School, said South Dumpling was home to about 100 cormorant nests, with about 70 of them clustered in one area on the ground. He said this was unusual because cormorants normally nest in trees, but their guano is so caustic that it has killed most of the trees on the island.

The class counted twice as many nests and eggs on Sandy Point, and Bednarz said that was likely because the island is significantly bigger than South Dumpling.

Haywood noted that South Dumpling also housed a small population of ducks, with nests that were full of eggs. In comparison, there were no duck nests on Sandy Point, though the class ran into personnel from the U.S. Fish and Wildlife Service conducting a piping plover study in the dunes there before departing for South Dumpling.

Later that week, the students used the data from the trip to compare to previous years and support or refute a hypothetical argument about whether to try to control bird populations on the islands.

Nash-Thompson said she was leaning toward not managing the island based on her experience on the trip because the students found more biodiversity on South Dumpling, where the trees were decimated by cormorant droppings.

Bednarz said other schools in the area also study the bird populations, and he was looking forward to seeing how the nest and egg counts would change for trips at the end of the semester, especially after Memorial Day on Sandy Point, a popular tourist destination.

a.hutchinson@theday.com