Crane Count
Each year, we survey Sandhill Crane numbers across the Central Platte River Valley.
These surveys track Sandhill Crane migration timing and habitat use along the Platte River between Chapman and Overton, Nebraska. Weekly flights are conducted during peak spring migration (mid-February to mid-April), typically for 9–10 weeks depending on conditions.
Beginning in 2024, additional fall and winter surveys were added in response to increasing numbers of cranes using the Platte River outside the traditional spring migration period.
Table from Ostrom, B.L. and A.J. Caven. 2026. Spring Aerial Sandhill Crane (Antigone canadensis) Counts of the Central Platte River Valley, Nebraska: Weekly Public Updates from 2016 to 2025. Report, Crane Trust, Wood River, NE, USA, 86p.
Access the article here.
Survey Timing, Route, and Team Structure
Each survey begins about 30 minutes before sunrise, when cranes are still gathered on the river. The team flies a consistent 85-mile route along the Platte River from Chapman to Overton, completing the survey in about an hour. On board are a pilot, a trained crane counter (Bethany Ostrom- middle), and a data recorder logging locations and counts (Elsa Forsberg- Left).
Roost Mapping and Population Estimation Methods
As the flight follows the river, roosts are mapped using GPS, and a subset is photographed to improve accuracy. Observers estimate flock sizes by counting smaller groups and scaling those counts to larger roosts, allowing thousands of birds to be assessed quickly.
Interpreting Data as Population Index
These surveys produce a reliable population index rather than an exact count. Some cranes leave the river or move beyond the survey area before they can be observed, and detection decreases farther from the river corridor. Because of this, the method consistently undercounts birds, but in a predictable way.
Our aerial crane surveys began in 1998.
Early work focused on documenting roost locations using video, later shifting to GPS-based mapping for improved accuracy. Since 2002, surveys have been conducted using standardized weekly aerial flights, with a brief gap in data collection during 2011–2012.
Over time, methods have been refined to improve accuracy, including the introduction of bias correction techniques in 2016. Public updates began in 2015 and became a consistent weekly effort shortly after.
Today, these surveys continue as one of the longest-running datasets tracking Sandhill Crane migration in the region.
These surveys do more than count cranes.
They help researchers track changes in crane abundance over time, understand migration timing and stopover patterns, and monitor how cranes use habitat along the river. They also provide insight into how land management practices, such as river restoration and vegetation removal, influence crane behavior.
Because cranes gather in large, dynamic groups, raw counts can vary from survey to survey. To improve reliability, researchers apply bias correction methods and confidence estimates, producing a more accurate abundance index rather than a precise headcount.
Together, this long-term dataset provides an understanding of how Sandhill Cranes interact with a changing river landscape.
Counting Cranes
Platte Basin Timelapse
Prefer to see our scientists in action? This short film from our friends at Platte Basin Timelapse walks you through how crane counts are done.
Frequently asked questions
Why do surveys happen in the morning?
Cranes are most reliably roosting on the river at sunrise, making them easier to count before they disperse.
Why use airplanes instead of ground counts?
The cranes are spread across an 85-mile river corridor, making aerial surveys the most efficient and consistent method.
How accurate are the counts?
A subset of flocks is photographed and compared to estimates to measure and correct for counting bias.
Why don’t surveys happen every week of the year?
Crane Trust focuses on peak migration from mid-February to mid-April, when the majority of cranes pass through the region, as well as a growing overwintering population that arrives in October and departs in March or April.