Facing the open ocean on the far edge of Sitka Sound, St. Lazaria Island is a seabird magnet that is rarely visited by humans or other mammals due to its foreboding topography. The lack of predators makes it an ideal nesting grounds for fork-tail and Leach’s Storm-Petrels, tufted puffins, rhinoceros auklets, glaucous-winged gulls and pelagic cormorants to name some species that raise chicks there. Leslie Slater, a wildlife biologist for U.S. Fish & Wildlife, has studied nine sea bird species on the island over the past 14 years. Perennial monitoring of population trends, productivity patterns and diet samples may yield significant insights, Slater said. For example, when a seabird species begins to lay its eggs earlier and earlier over an extended period of time it may be an indicator of climate change.
Wildlife biologist Leslie Slater, right, and biological science volunteer Liz Goldsmith reach into a rhinoceros auklet burrow to retrieve the chick from its subterranean chamber. Slater and her work crew have implanted a handful of artificial burrows into the earth to more easily conduct their research and locate the chicks. The auklets generally return to the same burrow year after year and their underground lodgings can be quite extensive; with the longest one documented measuring about 20 feet in length. “They can interconnect with other burrows because they do some maintenance each year,” Slater said. “You can have storm-petrels or rhinoceros auklets using the same burrow but just different branches of it. Because they keep digging or because roots grow in and it changes the structure of the burrow,” Slater said.
Liz Goldsmith places a rhinoceros auklet chick into a sack to weigh it. After it hatches, the infant auklet will sit and wait for its parents to return with high-energy fish like sandlance or herring to feed it, Slater said. This routine runs most of the summer until the day the chick’s parents fail to return. Then it’s only a matter of time before hunger pushes the bewildered orphan out of the burrow and into the world.
Biological technician Kitty Roush, left, and biological services volunteer Liz Goldsmith, look through spotting scopes at the cliff face where the thick-billed murres raise their chicks in clefts in the rock. They keep track of eggs, as well as hatch- and jump-dates. Behind them is the remnant of an antenna that once transmitted footage from a live video-cam trained on the murre colony. It broadcast to a monitor in Harrigan Centennial Hall in Sitka for a handful of years, beginning in 2003. While visitors could gaze into the Anasazi style, cliff-dwelling habitat of the murres, it’s rumored it also drew in local fishermen who might glean a weather report for the conditions out near Cape Edgecombe. The biologists installed the camera to conduct research. “We wanted to see which fish were being brought to the chicks and that information just isn’t available anywhere else,” Slater said, “Although the camera would work for the incubation time, it would always break just before the eggs started hatching.” The camera has since fallen into disrepair and the funding for its’ upkeep has dried up.
The thick-billed murre colony balances on a precarious precipice above the Pacific. When it’s time for the murre chick to depart, the father calls up from the sea to encourage it to jump. When it finally leaps, either on its own accord or with a helpful nudge, a few other mature murres ferry down alongside it. After the chick lands, usually with a belly flop, the other murres fly back up to the colony leaving the youngling to swim out to sea with its’ father. They swim out to sea together won't return to St. Lazaria Island for at least two years.
One of the perks of living on St. Lazaria is getting to visit the island’s sea cave during a minus tide. From left, Liz Goldsmith, Kitty Roush, and Leslie Slater peer at the neon sea sponges, oozing urchins and studded starfish that coat the rocks. Working for the summer on St. Lazaria Island can be dreamlike. The island is a bird Mecca, almost holy. On clear starry nights, the researchers often choose to sleep outside where they can hear the dense serrated coos of the Storm Petrels who have returned from a day of fishing to feed their young. Earlier this summer, students from the Cornell Lab of Ornithology Macaulay Library visited for the week to collect seabird audio. While their gatherings haven’t been posted yet, you can listen for free to the sounds of some other Leach’s Storm-Petrel using their search option at http://www.animalbehaviorarchive.org
A glaucous-winged gull soars on the perimeter of its’ colony past the rocks that thrust up from the center of St. Lazaria Island. Though St. Lazaria is only a 45-minute skiff ride from Sitka, the careening, constant cries of the birds, the radical rock formations, and the muscular ocean surge impregnate the island with a sense of remoteness and isolation.
Sunday, September 2, 2007
Posted by satsuma at 5:45 PM