The whooping crane, Grus americana, is the largest bird in North America. Its feathers are completely white except for black wing tips, a red patch on its forehead, and black patches on its head. Standing five feet tall and soaring on an eight-foot wingspan, these cranes are surprisingly endangered. It is hard to imagine a bird that large and think of it as anything but invincible. Unfortunately, whooping crane numbers plummeted in the late 1800s and early 1900s. Driven by habitat loss and hunting there were only 15 left by 1941. Without the creation of conservation organizations and programs in response to factors hurting whooping cranes, they might be extinct.
Whooping Crane Meets Crane Trust
Our organization, the Platte River Whooping Crane Maintenance Trust, otherwise known as the Crane Trust, was founded in 1978 when Grayrocks Dam was being constructed on the Platte River in Wyoming. In the construction process, this dam was seen as a threat by the state of Nebraska and the National Wildlife Federation. It had the potential to reduce irrigation and harm wildlife. To keep building this dam and satisfy the requirements of the Endangered Species Act the Missouri Basin Power Project, owners of Grayrocks, funded the Crane Trust’s work. The Crane Trust was designed to protect, restore, and monitor a swath of land and river on the Central Platte River Valley. A vital stop for migrating whooping cranes traveling between Aransas National Wildlife Refuge, in Texas, and their breeding grounds in Wood Buffalo National Park, in Canada.
Today, through exhaustive conservation efforts such as land management, scientific research, and education we, as part of a larger conservation community, have succeeded in bringing their numbers up to 836 individuals as of 2022. 134 individuals are in captivity as part of a captive breeding program, 293 are in wild reintroduced populations, and we protect and restore land that the only self-sustaining wild migratory flock of 543 use on their migratory journey.
We manage the landscape to support the Platte River, lowland tallgrass prairie, and shallow wetland habitats (wet meadows and shallow marshes) for whooping cranes and other migratory bird species. The Platte River is disked when water levels are low to prevent woody species from taking hold. Woody plants overtake riverine and shallow wetland habitats by stabilizing sediments, overtaking prairie plants, and reducing visibility. Shallow wetlands, much like the river, are full of live prey, which provide whooping cranes with a balanced diet when mixed with leftover corn.
Our science research makes managing the land and river to the best of our ability possible. If a new management tool or method is used, our biological monitoring program will unveil its negative consequences through data collection and analysis. As years go on, our management style will become more refined, but never perfect since there are more unnatural stressors today from things like river water diversions, invasive species, and climate change. Understanding the reason for each thing we do and then testing current “best practices” provides us with an understanding of how to improve management in the future.
All this acquired information leads us to share our findings with you through blogs, social media platforms, scientific papers, speaker series held at the nature and visitor center, and more.
How We Monitor Whooping Cranes
To monitor whooping cranes, we have to know where they are first. Our Threatened and Endangered Species Specialist, Dave Baasch, holds the key to finding wild whoopers. He has access to telemetry data, allowing us to find whooping cranes via GPS coordinates and complete migration behavioral surveys. In case you were wondering, only a portion of the 543 individuals that migrate through the central Platte River valley are equipped with a radio tracking transmitter. The transmitter looks like a black rectangle with white tape along its edges and only sends Dave a new location every four hours. Due to this fact, we were up by 5 am to receive coordinates or go back to bed. In the afternoons we were always ready to drive to coordinates before the whoopers flew off, but were unsuccessful many times. After driving around or waiting for the sun to rise and finding our individual or group of whooping cranes, it is time for a survey.
The surveys we conducted looked at behavior, habitat, proximity to powerlines, nearest stand of trees, the occurrence of aircraft flight overhead, identifying individuals, and more. Within the behavioral portion of the survey, we looked at each individual’s behaviors every minute for 30 minutes when possible. Their actions fall within seven behaviors: foraging, conspecific social interaction (interacting with another whooping crane), interspecific social interaction (interacting with a different species of animal), being alert or defensive (head straight up and looking around), flying or walking, loafing (doing nothing/resting), and preening (straightening and cleaning its feathers).
What Was Found
While collecting data this fall our team recorded 22 unique whooping crane groups in the Niobrara and Platte River Valleys. In total, there were 93 individuals consisting of 78 adults and 15 juveniles. Through the acquisition of 1,587 instantaneous scan samples, we documented 6,387 total behaviors. While documenting behaviors these whooping cranes inhabited cornfields, palustrine wet meadows, lacustrine wetlands, and rivers. Foraging/drinking was the most common behavior in cornfields, palustrine wet meadows, and rivers. Loafing was the most common in lacustrine wetlands. There were seven possible aircraft interactions from 235-500m above ground. Around helicopters and chinooks, whooping cranes jumped and acted as if they were going to take off, but did not and small fixed-wing planes elicited no reaction. There were 6 fish consumed during observation, five ranged in size from 4-5 inches and one was 8 inches. The identified fish species were river carpsuckers or quillbacks, gizzard shad, and a river chub. In one instance an adult passed a fish to a juvenile. Bald eagles were recorded interacting with 15 adult and 2 juvenile whooping cranes on 4 occasions. During the first interaction, one whooping crane chased off the bald eagle, during another the whooping cranes flew off, and in two other interactions the Whooping cranes ignored the bald eagle.
All of this information comes from a recent report prepared by Dave Baasch and Brice Krohn, President and CEO of Crane Trust, from the fall of 2023. If you would like to get a more in-depth understanding of what I outlined above or see pictures of these whooping crane behaviors, you can download this article with the link below.
Whooping Crane Diurnal Behavior and Natural History during Migration in the Central Great Plains: Progress Report – Fall 2023
Why Whooping Cranes Are Important
Despite the whooping cranes' drop in population size, they still have intrinsic value and serve ecological purposes. While they are both cranes, whooping cranes fill a different niche than sandhill cranes. Whooping cranes are more predatory, feeding on larger vertebrates such as fish. Both species use very similar habitats when in the CPRV and may have to compete for proper riverfront property. While we know a lot about North America's largest bird, there are many unknowns to be uncovered. Understanding the full extent of how they affect, and are affected by, the environment is of great importance to all scientists involved in monitoring whoopers. Conservation organizations such as the Crane Trust are driven to aid in the growth of the whooping crane population, so we can see the full strength and majesty of these birds return to the plains.
Whooper Watch
If you see a whooping crane in the Central Platte River Valley be prepared! Look through the Whooper Watch section of our website to learn whooping crane viewing etiquette, how to report a sighting, and what information is included in a report. Below is a link to the website.
Whooper Watch : What We Do : About : Crane Trust
Thank you to Bethany Ostrom, Josh Wiese, Megan Soldatke, Kylee Warren, and Dave Baasch for collecting data on whooping cranes this fall!
See you in the next blog!
Matt Urbanski,
Saunders Conservation Fellow
murbanski@cranetrust.org
References
History : About : Crane Trust
Whooping Crane : Research : Conservation : What We Do : About : Crane Trust
Whooping Crane (cranetrust.org)
Whooping Crane - International Crane Foundation (savingcranes.org)
Whooping Crane | National Wildlife Federation (nwf.org)
