Biologists are buoyed by the first wave of white pelicans returning to the Chase Lake National Wildlife Refuge in central North Dakota.
BISMARCK, N.D. Biologists are buoyed by the first wave of white pelicans returning to the Chase Lake National Wildlife Refuge in central North Dakota.
But they're still clueless as to why thousands of the big birds abandoned their nesting grounds last year on the refuge, which for a century had been the site of the largest nesting colony of white pelicans in North America.
The nesting grounds were left littered with eggs and chicks, none of which survived, said Ken Torkelson, a spokesman for the U.S. Fish and Wildlife Service in Bismarck.
Ten breeding pairs of pelicans were spotted on Tuesday at the refuge, Torkelson said. Pelicans also have been spotted en route to the refuge from their wintering grounds along the Gulf Coast to Florida, he said.
Biologists are hopeful the big birds will arrive by the thousands over the next few weeks, but it's too early to determine if they will reproduce.
Normally, the pelicans stay at the refuge through September, raising their young and feasting on crawfish, small fish and salamanders from small prairie ponds within a 100-mile radius of the refuge.
"We're encouraged," Torkelson said. "There are still no guarantees that things will be back to normal ... It will be awhile before we can say we're out of the woods on this."
About 28,000 pelicans showed up to nest at the 4,385-acre refuge north of Medina in early April last year, but they took off in late May and early June. A couple of hundred "loafers," or pelicans not yet of breeding age, stayed to feed at prairie potholes in the Chase Lake area, refuge managers said.
Wildlife officials have checked air, water and soil quality at the nesting grounds. They also have checked for diseases, food supply, predators and other possible factors.
The mystery of the pelican exodus may never be solved, Torkelson said.
"I think we've done everything we can do," said Kim Hanson, who heads the Arrowwood complex, which includes Arrowwood and Chase Lake National Wildlife Refuges. "Now it will depend on the birds, I guess."
Biologists plan to capture 10 adult pelicans after their eggs have hatched. Some $40,000 worth of electronic tracking equipment will be harnessed to the pelicans to monitor their movements when they leave the colony, Torkelson said. Long-range video surveillance cameras and extra crews also will monitor the pelicans this year.
Fences and signs have been installed around parts of the refuge to keep out predators and people.
Hanson said people are "pretty understanding" when told the nesting grounds will be off-limits this year. They still can see pelicans in the area when the big birds are making feeding runs, he said.
In fact, Hanson said, the birds should be hard to miss. The white pelican is one of the largest birds in North America, measuring 6 feet from bill to tail and weighing up to 20 pounds, with a wingspan of nearly 10 feet.
Source: Associated Press