Even though it's February, sandhill cranes are flowing into central Nebraska

Fast and early.

That’s how Andy Caven describes the start of this year’s sandhill crane migration. He’s the director of conservation research at the Crane Trust in Wood River, Nebraska.

About 27,500 cranes were counted on the Crane Trust's first aerial survey on Feb. 14. The report also listed 23,200 dark geese, 73 trumpeter swans and seven bald eagles.

That’s one of the highest week one totals in the 20 years that the Crane Trust has been conducting surveys over an 82-mile stretch of the Central Platte River Valley from Chapman to Overton. The average for the first survey over the past 20 years is between 4,000 to 8,000 cranes.

“We had a high number for this early in the year,” Caven said. “Warm droughty winters in their wintering grounds mean they come earlier. That’s been a trend. We keep getting these early migrations.”

On average, the sandhill crane migration has advanced a day each year over the past few decades, per Crane Trust research published in the Western North American Naturalist. That doesn’t sound like much for just a year, Caven said, but when you look at it long-term, that translates into almost a month earlier migration than in the past.

Sandhill cranes both arrive earlier and stay longer, he said. In more than 50% of the years in the past decade, a few hundred to several thousand cranes have spent the winter along the Platte River. That had occurred only a couple of times over the preceding 50 years per published records.

Crane numbers used to peak in early April, and now that comes most often in mid-March. A one-degree difference in winter temperatures and in drought conditions affects when the cranes migrate.

“Over time with climate change, they are coming earlier,” Caven said. “Climate change and winter food availability. We increasingly get good numbers in February, which didn’t used to happen.”

The cranes that stop in central Nebraska overwinter from coastal Texas to southeast Arizona, south into Chihuahua, Mexico, and north into the panhandles of Texas and Oklahoma.

The clear trend this year in those areas is drought, Caven said, which affects the birds’ food supply and wetland habitat availability. It’s also been warmer.

In Nebraska, the birds are able to feast on waste grain and invertebrates in meadows before heading north to their breeding grounds throughout Canada, Alaska and even into Siberia.

Surveys are done for 10 weeks in the spring. Numbers often double by the second weekly aerial survey and can occasionally increase sharply in the third week depending on weather conditions.

About 1 million birds are in the Central Platte River Valley at the peak of migration and another 200,000 use the North Platte River Valley. Data suggests the population is growing overall.

The exact peak date has been highly variable across the last couple of decades, Caven said.

“It’s very weather dependent, and a cold snap could slow migration down and bring it back to normal,” he said. “Whether or not we sustain this quick migration pace will depend on weather conditions, not only in the CPRV but also in the southern Great Plains.”