|A banded white pelican chick at Chase Lake National Wildlife Refuge faces many threats — including storms, disease and predators — before it is mature enough to fledge. Pelicans’ earlier initiation of nesting is putting the chicks at greater risk. Photo: USFWS. Download.|
Each April and May, in a rite of spring, American white pelicans begin arriving in their Northern Plains breeding grounds from the Gulf of Mexico. But for the last several decades, something has put the large birds ahead of schedule. That something, researchers believe, is warming tied to climate change — the same change that’s recently brought egrets, ibis and herons to nest on the refuge, well north of their long-time nesting areas.
The early birds are paying for their two-week head start with more chick deaths from severe spring storms. For the pelicans, this setback comes on top of other major stressors, most notably West Nile Virus. If — and how — the pelicans will adapt is unclear.
One place scientists and wildlife managers are monitoring is Chase Lake National Wildlife Refuge in central North Dakota. The Chase Lake colony is one of the world’s four largest colonies of American white pelicans.
As many as 35,000 white pelicans nest on Chase Lake’s remote wilderness islands. That’s up from 50 in 1908, when Teddy Roosevelt established the refuge to protect the species from being hunted to extinction. Despite the colony’s rebound, the great-winged birds are still considered vulnerable because they have so few breeding areas.