Researchersmonitor continuing decline in seabirds

Published on Thu, Mar 3, 2005 by ack Kintner

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Researchers monitor continuing decline in seabirds

By Jack Kintner

“You have to get up early for ducks,” said Dave Nysewander, a trained biologist and project leader for the Washington Department of Fish and Wildlife (DFW). Last Friday he and his team of eight people were nearing the end of a three weeks project that involved trapping, measuring and tagging Scoters (rhymes with “motors”), a species of diving sea duck, in four areas of the Puget Sound basin, and after Olympia, Bainbridge Island and the Whidbey-Camano Island area, Birch Bay was to be their last stop.

Nysewander said that Scoters along with other species, such as Grebes, have shown significant declines in the past 25 years. The reason for this is complex, he said, but based on his survey data the DFW is fine-tuning its wildlife management practices to help preserve the remaining populations. The decline in available eel grass beds due to unregulated shoreline development may be one factor, he said, since Scoters feed on herring roe in the spring before migrating northward to breed in Alaska and Canada.

The DFW’s 26-foot aluminum boat named “Harlequin” led a convoy of several smaller boats out of the Birch Bay Village marina at 4 a.m., well before dawn, to set out mist traps strung like invisible tennis nets between two poles mounted on floats that were molded like decoys. “The ducks fly shoreward before dawn,” Nysewander explained, “and when they get tangled in the net then one of our smaller boats will retrieve it and bring it to our larger boat where it’s put into a small animal carrier.”

Once back at the marina, Nysewander patiently and gently measured each individual bird in the same way, holding it in his lap until it calms down. He weighed it, calling out “1,364 grams” (about three pounds) to Brad Otto, the record keeper for the day. He measured the culmen, or length of the bill, and its width, the tarsus (lower leg) and the chord of the wing, determined by measuring the ninth primary feather. On one bird he noticed a dislocated toe and made a mental note to point it out to the DFW’s consulting veterinarian Dr. Briggs Hall.

Hall would be coming by in the late morning to surgically implant tracking transmitters in some of the ducks. “It’s opened up a whole window of information for us,” Nysewander explained, “and we’re beginning to get some insights about where they go when they leave here.” Last year 49 transmitters were implanted into White-winged and Surf Scoters in different areas of the Puget Sound basin. Twenty-five of the transmitters were small vhf units that broadcast “line of sight” to a receiver, meaning that to pick up the signal a researcher has to have an unobstructed view of the bird even if it’s too far away to literally see. The receivers cost about $500 apiece and are usually detected by overflying aircraft.

The other 24 ducks were fitted with $2,700 satellite transmitters that can be tracked virtually anywhere, and have given Nysewander and his team a graphic representation of where the birds go once they leave our area and where they nest. “They’re expensive, all right,” Nysewander said, “and we’re anxious to get them back if people find them.”
Hall said that the implant operation is not particularly hard on the bird and takes “about 45 minutes per duck, give or take. We have one satellite transmitter that’s about to take a ride on its third duck.”

The batteries in the units last through a season because they’re turned off most of the time. “We’ll run them for six hours or so,” Nysewander said, “and then turn them off for four to six days, especially when the females are nesting up north.” The males, on the other hand, seem to take off once the females are brooding, giving in to a kind of duck wanderlust.
Several tracks showed males leaving the nesting grounds in northern Saskatchewan and heading straight for the Arctic Ocean, then to the Bering Sea before heading straight back to western Washington, almost as if they’d hitched a ride on Alaska Airlines.

“There’s some interesting data,” Nysewander said. “The Scoters all return to the same wintering areas where they were captured. When they go north to breed, 75 percent of the birds that originate in this area (Birch Bay) go to northern B.C. and then east into Saskatchewan and the Northwest Territories, but if they come from the southern sound they tend to go to Alaska.”

“After molting, females return to our area with the young birds in groups,” he continued, “almost as if helping each other make the long journey through the mountains of B.C. The males are highly diverse in their behavior, eating what they can here and there.” Nysewander explained that Scoters have a bill like a can opener “because that’s what they do, pry shellfish out from underwater rocks, although one male Surf Scoter seems to be hooked on herring roe.” The individual stayed in the northwest all year and never went north in the spring to the breeding grounds. It molted in Florence, Oregon, and then came back north to Olympia, then went back to the Oregon coast and continued down to Crescent City, California. He was essentially following the herring spawn all over Washington and Oregon before finally going north last spring.

One thing that Nysewander emphasized was the importance of the Cherry Point, Birch Bay and Semiahmoo eel grass beds for all the Scoters migrating through the area and for other sea birds as well. “The area from Boundary Bay south to Bellingham Bay is crucial,” he said, “as the birds come here in the spring as a staging area prior to migrating north. If they don’t get enough to eat then the stress of flying all the way to the breeding grounds and brooding can be too much.”

Nysewander said that he’s working on a beta version of a website where tracking data can be shown. Until then, he can be contacted at the Marine Bird and Mammal Component, Puget Sound Ambient Monitoring Program, Washington Department of Fish and Wildlife, 600 Capitol Way N., Olympia, WA 98501-1091. By telephone or email: 360/902-8134; nysewdrn@ dfw.wa.gov.