Pelican population increases at North Dakota wildlife refuge
BISMARCK, N.D. (AP) — Abnormally dry weather may have helped boost the number of American white pelicans nesting in north-central North Dakota known as North America’s largest refuge for the big-billed birds.
Results of an aerial survey released Friday by the U.S. Fish and Wildlife Service show 16,600 pelicans nesting at the Chase Lake National Wildlife Refuge, an increase of about 2,400 birds from a year ago when high water gobbled up much of their nesting grounds.
The Chase Lake pelican population has ranged from around 6,000 birds in 1974 to 35,460 in 2000, wildlife officials say.
The refuge went through two years of abandonments and die-offs in 2004 and 2005 that were blamed on coyotes and a combination of weather and disease.
The main nesting island was first used by pelicans in the early 1990s. Wildlife officials say the island has shrunk dramatically in recent years, as lake levels have risen from snow and rain runoff, and from groundwater overflow, heavy rains and water that has migrated from other nearby lakes.
Jennifer Jewett, a wildlife refuge specialist, said the island is only about half the size it was seven years ago, but should “be stable for a few years.”
Drought conditions that have parched North Dakota may have helped curb rising water levels main nesting island, she said.
Biologists began conducting aerial surveys of the nesting grounds in 1972. They scan photographs of the refuge into a computer program to estimate the number of breeding birds.
The pelicans winter mainly in the Gulf Coast states but some fly to North Dakota beginning in April from as far away as Florida and California to nest. The birds normally stay in North Dakota through September, caring for their hatchlings and feasting on crawfish, small fish and salamanders from small prairie ponds within a 100-mile radius of the refuge.
The refuge near Medina normally draws thousands of tourists annually to see the birds that weigh up to 20 pounds, have a wingspan of nearly 10 feet, and measure 6 feet from bill to tail. The white pelican lives about 25 years, and breeds only once a year. Males and females take turns caring for their young. Typically, two eggs are laid in each nest, but only one chick survives.
Pelicans have been monitored at Chase Lake since 1905, when the birds numbered about 50. U.S. President Theodore Roosevelt designated the site as a bird refuge in 1908, after many of the birds were being killed for their feathers or shot for target practice.