These Birds Know How to Fuel Up Before Breeding Season

An unprecedented number of sandhill cranes have made a pit stop in central Nebraska, the United States, eating and strengthening their social bonds before continuing their journey to their breeding grounds in Alaska, Canada, and eastern Siberia.

“We do have occasional small groups of cranes overwinter […], but we have never before seen this large of a group stay here for so long,” says wildlife biologist Bethany Ostrom. “Many factors play into cranes’ decisions when to migrate, many of which we probably do not understand.”

The yearly Nebraska’s spring stopover spans from mid-February to mid-April, with the birds staggering their arrivals and departures. The first count is between 6,000 and 8,000 cranes in a typical year. Last year, at the same time, 6,400 cranes were counted. This year, the number reached 38,000 birds – most likely lured by mild winter temperatures – the highest record since 1998 when aerial surveys began. Their numbers usually peak around mid-March with 500,000 cranes. Each spring, 80% of all the world’s sandhill cranes stop at Nebraska’s Platte River. The bird spends most of this month in Nebraska fattening on corn kernels, putting on as much as 20% of its body weight during its stay.