Erratic white pelicans due to return to refuge

White pelicans at the Chase Lake National Wildlife Refuge in central North Dakota have baffled biologists in recent years with no-shows, massive die-offs and hurried departures. The big-billed birds' expected return to their nesting grounds in a few days may add to the mystery, said Paulette Scherr, a U.S. Fish and Wildlife biologist. "The birds are going to return," she said. "But will they have problems? We don't know that." The white pelicans — among the largest birds in North America, measuring six feet from bill to tail — normally stay at the Chase Lake refuge through September, raising their young and feasting on fish and salamanders from small ponds known as prairie potholes. The first chicks hatch around mid-May. In recent years, the white pelican population at the 4,385-acre refuge north of Medina has plummeted from 35,466 birds in 2000 to about 14,000 last year — the lowest number since 1992. Wildlife officials said nearly 30,000 pelicans left the refuge in 2004, leaving their chicks and eggs behind. A year later, the refuge saw a massive die-off of pelican chicks, followed by an exodus of their parents. Biologists say less than 300 chicks likely survived in 2005. The abandonments and die-offs in 2004 and 2005 have been blamed on coyotes and a combination of weather and disease, though nothing has been proven, Scherr said. "Honestly, we don't have all the answers," she said. The giant birds, which can weigh up to 20 pounds and have a wingspan of nearly 10 feet, usually live for about 25 years and breed once a year. Typically, two eggs are laid in each nest, but only one chick survives. They spend the winter months along the Gulf Coast. The pelicans' puzzling activity does not have biologists too concerned. "We know there will be some boom and bust years," Scherr said. "We're not worried — yet." The U.S. Fish and Wildlife Service has been monitoring the pelicans at Chase Lake since 1905, when the flock numbered about 50. President Theodore Roosevelt designated the site as a bird refuge in 1908, after many of the birds were being killed for their feathers and for target practice. Bradley Moser, president of a local sportsmen's club in Medina, said the pelicans are probably looking for better nesting grounds. He said areas where the pelicans nest are knee-deep in bird waste. "They're just tired of nesting in their own (excrement)," he said. "After 125 years of nesting there, I can't say I blame them." Moser calls it a biological correction. "Mother Nature is smart enough to know that after so much time you got to move to a different area," he said.