of Phalaropes a Mystery
(Published by The Quoddy Tides, September 27, 2002)
One of the Quoddy region's greatest natural mysteries remains unsolved. Twenty years ago, the red-necked phalarope could still be seen from late July to early September in great numbers off the coast of Eastport and Lubec, and Deer and Campobello Islands in New Brunswick. Like other migratory birds, this small shorebird with a sandpiper-like appearance relied on the abundance of marine life found in the nutrient rich waters of the Bay of Fundy.
"The red-necked phalarope once passed through this region in numbers as high as 2 million, perhaps a fourth of the world population," conservation biologist Charles Duncan reports. "This was reported as far back as John James Audubon."
Duncan was a resident of East Machias for 17 years, and taught at the University of Maine at Machias until 1999. He is now working with The Nature Conservancy's Migratory Bird Program, which focuses on habitat protection.
"From 1985 to 1990, I saw the red-necked phalarope numbers drop from 20,000 a day to 2,000 a day, to 200, to 20, then zero. No one has found another spot where they may have shifted their migration. This decline is absolutely unexplained," Duncan says.
However, much speculation rests on a change in the availability of their food source, a tiny marine animal called a copepod. Roughly 80% of the red-necked phalarope diet was composed of a large copepod (about 3 millimeters in size) with the scientific name Calanus finnmarchicus. This species of copepod is extremely abundant in the Bay of Fundy, and is the same copepod that right whales feed on at depth. The copepods do not like sunlight, and migrate away from surface waters during daylight hours when the birds are feeding.
"What phalaropes need are oceanographic features such as tidal upwellings to push these animals up to the surface. Copepods can't fight a strong vertical current," says seabird researcher John Chardine of the Canadian Wildlife Service (CWS). "The tremendous tides in the Bay of Fundy region create these upwellings and concentrate the copepods at the surface."
Food was so abundant and close to the surface in the Quoddy area that phalaropes did not have to resort to their normal feeding method of rapidly twirling in the water to bring food to the surface. Instead they just jabbed with their needle-like bills at individual copepods.
This past August, a study was initiated by Chardine to take another look at the food resources available to the birds in the areas where they once congregated. "Over the years, more and more interest has been shown toward finding an explanation for the red-necked phalaropes disappearance," says Chardine. "We are now trying to determine if the preferred food of the red-necked phalarope is still available. Our study was conducted during a one-week period right at the height of when the birds should have been there, in late August."
Chardine repeated methods used for a similar study conducted in the early 1980s through the Huntsman Marine Laboratory and the University of Guelph in Ontario, when the Bay of Fundy still boasted tremendous numbers of migrating red-necked phalaropes. The researchers towed a net behind a fishing boat in different areas around Deer and Campobello Islands. "We caught whatever was in the top 20 centimeters of surface water with a very fine mesh, catching everything of interest to birds," explains Chardine.
For the recent study, they also conducted bird surveys and plankton tows over at Brier Island, Nova Scotia, where red-necked phalaropes are still known to occur with their relatives the red phalarope, in order to have a control site with which to compare the Quoddy data.
Chardine states, "We now have 150 mason jars full of copepods and other shrimp-like animals to analyze. While we don't know exactly what's in them yet, it does not look like we got any of the large copepods that were the preferred food of the red-necked phalarope on the Deer Island side."
This does not mean the copepods are not there, but it may mean that they are not rising as far up in the water column as they did in the past, and are now out of reach of the red-necked phalaropes' bill.
The red-necked phalaropes prefer the inshore areas and feed on these larger copepods, while the red phalaropes prefer the offshore islands, and tend to feed on smaller copepods. The bird counts off Brier Island show roughly twice as many red phalaropes as there are red-necked phalaropes. "There is the suggestion that there are more red-necked phalaropes off Brier Island than there used to be," says Chardine.
According to Chardine, there are indications that both red-necked phalarope and red phalarope numbers are declining in their Arctic breeding grounds partly because of global warming and the over-population of snow geese.
On the wintering grounds, red-necked phalaropes are vulnerable to El Nino events. Offshore of western South America, where the phalaropes spend the winter, a lot of cold upwelling brings animals up to the surface, just as in the Bay of Fundy. El Nino stops these upwellings from occurring, so the birds have nothing to feed on. A strong El Nino occurred in South America in the early 1980's, and twice in the 1990s.
Chardine is not without hope, however. "I strongly suspect they are out there somewhere. They could be more spread out in smaller pockets here and there." With so much coverage on the coastline by birdwatchers these days, he feels it would be hard to miss a large gathering. And, there is some anecdotal information that red-necked phalaropes are being seen off Mt. Desert Rock in large numbers.
"In terms of conservation, I doubt we will find anything that we can do anything about," Chardine says. "It is more that we are trying to find out what is going on, and confirm that the red-necked phalarope population is okay."
While a sure explanation is as elusive as the birds themselves, it is interesting to consider that a slight change in environmental conditions can trigger a tremendous change in animal behavior. If anyone has information on sightings of red-necked phalaropes or red phalaropes off the coast of Maine, please contact John Chardine at email@example.com or (506) 364-5046.
This column was prepared by Cheryl Daigle. Cobscook Soundings was a monthly column produced by the Maine Chapter of The Nature Conservancy. Its purpose was to share what is known about the workings of the Cobscook Bay marine environment, so that all who make decisions about the use or care of the bay have the best available information.
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