North Dakota’s Chase Lake National Wildlife Refuge is the nation’s largest sanctuary for American white pelicans. It hasn’t always been so. Early last century, unregulated hunting of the birds for their plumes had pushed them to the brink. In 1908, President Theodore Roosevelt took action, designating Chase Lake as a bird refuge. Only 50 pelicans were counted there that year. Since then, pelicans have regularly returned – and flourished.

Still, when today’s 30,000-strong flock arrived at Chase Lake Refuge last spring, the pelicans’ primary nesting island had shrunk by about 40 percent since the previous spring.

For reasons yet unknown and despite normal precipitation, the lake’s water level is rising. Since the 1990s, the island has slowly shrunk, leaving less and less pelican breeding habitat. Not since records have been kept, however, has so much habitat disappeared so quickly.

Other anomalies have stumped biologists. In 2004, nearly 30,000 pelicans left the refuge, abandoning their chicks and eggs. The following year, there was a chick die-off. Again, adult pelicans abruptly departed. The exodus defied explanation. It was so massive that biologists hypothesized several factors must be at play.

None of this seems to have had permanent impact on the pelicans; they are raising chicks by the thousands. Still, the anomalies are troubling.

Coincidentally, Chase Lake Refuge hosts a National Ecological Observatory Network (NEON) core site. Refuge manager Neil Shook is looking to NEON to help solve the mystery.

Funded by the National Science Foundation, NEON is building 106 sites nationally to measure causes and effects of climate change, land use change, and invasive species on a continental scale. Once it is fully operational in 2017, NEON will provide free data, educational resources and scientific infrastructure for research.

NEON will also monitor atmospheric conditions (amount of carbon released and absorbed, temperature, humidity) and soil conditions (pH, humic matter, exchangeable acidity). Fiber optic equipment will live-stream data to NEON headquarters in Boulder, CO, where they will be analyzed and made publicly available.

“These data will be offered up in real time to any entity that wants to use them,” says NEON manager Andrea Anteau.

NEON also will deploy seasonal field crews to observe biological systems. For instance, crews will conduct annual breeding bird surveys and trap mosquitos and ticks to study how climate change might affect the insects’ role as disease vectors.

This isn’t the first time Chase Lake Refuge has housed a major scientific research center. Woodworth Station Waterfowl Production Area, site of the refuge’s headquarters, was the primary U.S. Fish and Wildlife Service facility to study the life history, habitat needs and potential management of waterfowl and other migratory birds from 1963 to 1989. It was shuttered when the Service lost its biological research arm, but data remain valuable.

“So much of what we know about wetlands and waterfowl – all of that research – started here at Woodworth Station,” Shook says. “NEON will allow us to leverage that valuable 50-year baseline and also enter into a new and exciting realm: climate change research.”

Species are responding to climate change in unpredictable ways, Shook says. Some once-complementary species are no longer interacting, which disrupts complex interrelationships ecosystems need to thrive.

“We know that some birds are nesting earlier than ever before,” he says. “Pelicans are arriving 16 days earlier than they did when we started documenting their arrivals 50 years ago. Some plants are flowering up to three weeks earlier than they did previously. These relationships are out of sync, and we need reliable data to measure the changes so we can make wise management decisions.”

Meanwhile, Shook keeps an eye on the Chase Lake island mystery and other unexplained changes in prairie plant and animal communities.

Ryan Moehring is a public affairs specialist at the Mountain-Prairie Region office in Lakewood, CO.