A brisk wind blew east to west over the island of St. Croix Sunday morning. Big birds were silhouetted by a dark blue sky and the occasional puffy white clouds, darting as opposed to gliding, as if the weather was worrisome.
Small barn swallows, however, flew lower, skimming above the field outside the East Marine Park office.
Bill Boyton and his partner, Tony Vanderperk, counted 30 of the birds with the orangish breasts and blueish-black backs. The pair got a special treat as a yellow warbler flew around them and landed on their vehicle. The bird, which probably flew down from North America for a winter residency, was making sure he was included in the Audubon Society’s Annual Christmas Bird Count.
This was not the only treat of the morning for Boyton, who organizes the annual bird count on St. Croix, and novice Vanderperk, who was getting training. At a pond farther west on the South Shore, near Ha’Penny Beach, they saw an osprey catch a fish and then perch in a tree eat it.
“It was an absolutely wonderful experience,” Vanderperk said.
Boyton said he and Vanderperk expected to visit eight sites during the morning.
“We go. We count the birds. We move on,” he said.
The total number of birds counted on St. Croix would’t be compiled until Monday, but it appeared to Boyton that the count at the ponds on the eastern part of the island was going to be down again this year. The count there was down last year because of drought conditions. The ponds were relatively full this year, but Boyton pointed out that the food for the birds – crustaceans, mollusks, amphipods, insects, fly larvae, and algae – does not quickly regenerate after a pond has dried.
This was the 117th year the international organization has conducted the count. People on St. Croix have been participating for the past 17 years.
“The count helps scientists evaluate the environment," Boyton said. "The growth or decline of overall bird population often indicates changes in the local environment that otherwise would be overlooked.”
Changes in numbers and in the types of species on the island helps determine whether or not a bird is put on the endangered list. It also gives support to identifying environmental dangers that are present on the island.
“With the wet conditions that we have had lately and the blessing of no major storms this season, we are looking for a count with record numbers this year,” he said.
The 2015 tally was 3,615 birds, including 75 different species. Identifying the birds can be tough, as illustrated when Boyton was identifying some sandpipers. There are 22 different species of sandpipers.
The bird count lasted from sunrise to sunset, but most of the counting was done in the morning, before, as Boyton said, “the birds flee the hot temperatures of the mid-day.”
Volunteer were counting all over the island Sunday. Boyton said a volunteer could do a count in one area or several. He said it depends on what the volunteer can and wants to do. Volunteers are given a tally sheet and bird-identification card. On the day of the event, they are asked to do a slow walk through the areas assigned and tally the number of birds of each species they sight.
Readers can click here to hear the yellow warbler’s song.
Detailed information about this year’s Christmas Bird Count and 2015’s results are available online at the Aududon website, which also maintains a historical record of all past bird counts.