In a global first, B.C. researchers have tracked several robin-sized seabirds — fork-tailed storm petrels — as they travelled up to 17,500 kilometres off the west coast of Vancouver Island in just over a month.
“This is the first time it’s ever been done,” seabird biologist Luke Halpin said in an interview. “In B.C. and Alaska these birds are not well studied. We really don’t know much about them.”
Fork-tailed storm petrels are found only in the North Pacific, including the west coast of Vancouver Island and Haida Gwaii. Population estimates are old and vary widely, from 300,000 to 1.3 million birds on the B.C. coast.
A research team captured 11 of the petrels — grey birds, weighing 50 to 55 grams apiece — on a breeding colony in late May in the Gillam Islands at the mouth of Quatsino Sound and fitted them with 800-milligram geolocator tags that measure light intensity to estimate the bird’s latitude and longitude. “There is no GPS technology small enough to use on animals this size,” Halpin explained.
The petrels travelled far and wide in search of food, spending four days on average at sea before returning to their nests.
The eggs and chicks can undergo long periods of neglect, infrequent feeding and limited incubation, he noted. “They are fed a very calorific and nutritious meal from their parents” that gets them between feedings.
“We should know where they feed if we are thinking about their conservation,” said Halpin, noting that their range overlaps that of oil tankers and other ocean-going ships.
After 40 days, researchers recaptured five of the petrels from the breeding colony. “We just pulled them out of the burrows, basically.”
Data from the geolocator tags showed that one bird cumulatively travelled 17,500 kilometres — more than 425 kilometres per day — during that time west of the continental shelf, although the average was 9,600 kilometres.
While one bird flew about 2,000 kilometres during just one feeding foray over a two-week period, most remained 300 to 400 kilometres offshore of the colony. “These birds are highly pelagic, built for spending life on the high seas — travelling long distances, remaining aloft, and expending minimal energy while doing so,” Halpin said.
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article: Larry Pynn
photo: Ingrid Pollet