MINNEAPOLIS -- About a year ago, 30,000 pelicans
abandoned their newborns and unhatched eggs and fled the Chase
Lake National Wildlife Refuge about 120 miles west of Fargo, N.D.
Researchers were stunned to find that the largest pelican
breeding colony in the world had become completely vacant as
the birds had scattered to refuges in the Dakotas, Minnesota,
Iowa, and southern Canada.
The incident drew international attention, with biologists
saying they considered the situation as perplexing a natural
phenomenon as crop circles. While the disappearance of thousands
of white pelicans remains a vexing natural mystery, the birds
are back this spring, though in much smaller numbers.
The arrival of about 11,000 birds this migration season is
seen as a hopeful sign.
''So far, things are going along as normal," said principal
investigator and wildlife biologist Marsha Sovada of the Northern
Prairie Wildlife Research Center in nearby Jamestown, N.D. ''But
if it's going to be the middle of July and we're still at only
5,500 pairs, we'll be scratching our heads some more."
She said 11,000 is only a partial count based on long-distance
observations because researchers are reluctant to spook the
birds by flying overhead, the usual counting method.
If there is another abandonment this year, researchers may
be able to figure out why. Biologists are going out three times
a week with binoculars to observe the birds, and a solar-powered
camera set up before the breeding season is trained on the peninsula
and the trio of islands on Chase Lake where pelicans gather,
Sovada said.
Most of the refuge, a remote 4,385-acre site, is closed this
year to the public. A 400-foot-long electrified fence was erected
near where the pelicans nest to keep out coyotes and other predators.
Later, Sovada said, researchers will place satellite transmitters
on 10 adult pelicans after their eggs have hatched to track
them for three years.
Much of the monitoring, including $40,000 for the satellite
transmitters, is being paid for as part of a study of West Nile
virus in pelicans, Sovada said.
There is no strong evidence to explain last year's abandonment,
said Ken Torkelson, spokesman for the US Fish and Wildlife Service
in Bismarck, N.D. The fence, for instance, is a proactive measure,
although few biologists think coyotes attacked the birds because
coyotes would have had difficulty reaching the islands. Also,
there were no carcasses to suggest an attack.
''We don't know what the problem was, so we're trying to eliminate
any problems we can think of," Torkelson said. So far, observers
report normal mating activity and can see adult pelicans squatting
on nests that presumably have eggs in them, Sovada said.
She said there probably will be fewer birds at Chase Lake
this summer than the usual 30,000 because there was little or
no procreation last year.
Theories abound to explain last year's woes. Ron Reynolds,
a biologist with the US Fish and Wildlife Service in Bismarck,
said a climate change caused the disturbance. Last summer was
among the coldest on record for much of North Dakota, with temperatures
about 5 degrees below normal near Chase Lake. It followed a
very dry spring that shrank wetlands, he said.
''Pelicans feed on the surface of the water, so the cool weather
may have put their prey a little deeper," Reynolds said. ''The
foraging success may well have been poor. . . . Pelicans value
self-preservation over reproduction. It's a physiological hormonal
thing they go through. They decided it was better to live another
year than struggle."
But other specialists note that the coldest summer on record
was 1992 and there was no similar abandonment that year. Biologists
also found that the young abandoned last spring had full bellies
of crayfish and minnows. Specialists say the fact that the offspring
were well fed suggests the adults dispersed quickly.
''For every Ron Reynolds theory, there's somebody equally
qualified with another theory," Sovada said. ''I don't know
if we're ever going to know. It seems like there's a little
bit of truth to every idea. In concert, maybe all of these things
together caused this event."
The abandonment at Chase Lake raised worry in Medina, N.D.,
a town of 450 residents about 10 miles from the refuge. It is
so proud of its connection to the bird haven that a white pelican
is painted on the local water tower.
Birders come from around the country to see the huge flocks
of majestic, wide-spanned pelicans.
''The pelicans are a big deal here," Medina city manager Bradley
Moser said. ''I was just like everybody else, not knowing. There
isn't much we can do about it, but it would be interesting to
know."
Innkeeper Janean Schmidt of the Chase Lake Country Inn in
Medina said the disappearance of the birds actually may have
increased demand last year.
''We still had a good turnout," she said. ''A lot of it was
curiosity. People came up to see what was going on. I don't
think the fact that the pelicans were gone really bothered them
so much."
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