Tom Stehn's Report: More About Whoopers
April 6, 2007
Meet Tom Stehn
Whooping Crane Coordinator, U.S. Fish and Wildlife Service

As you read Tom's report this week . . .
  1. When do many of the adult pairs start the migration from Texas to Canada? Explain why.

  2. What's Tom's "tall tale" this week?

  3. What are some important differences between Sandhill Cranes and Whooping Cranes?

  4. When is the most dangerous time in a crane's annual cycle?

Dear Journey North,

I can't tell you exactly how many Whooping Cranes have started the migration from Texas. That's because the aircraft I hire to fly in is having routine maintenance done. I hope to fly on April 10, right around the time when many adult pairs choose to start the migration. I'll have the latest counts for you next week, so stay tuned!
Photo B. Krein

A Tall Tale — and the Real Truth
It was exceptionally windy here the last week in March. Every day brought wind gusts as high as 40 miles per hour. I always joke with people that when it's windy like that, saying the Whoopers (which weigh only 12-15 pounds) could simply jump in the air with their wings spread and get blown north for the first mile of the migration before they would come down. That's a tall tale. Yet most of the Whooping Cranes chose to remain in Texas, knowing with their internal clock that it is still too cold up north to start their trip. The majority of the flock always starts migration the first two weeks in April. This allows them to reach Canada and build their nests in early May, just after the ice and snow have melted.

Whoopers are Different from Sandhills
Sandhill Cranes have a different internal clock than whoopers. Most Sandhills are currently on the Platte River in Nebraska and some are already starting the second part of their migration. The Sandhills spend up to 6 weeks on the Platte River, a phenomenon biologists refer to as staging. On the Platte, up to 600,000 sandhill cranes will feed and choose mates before they fly to their nesting areas. Whooping Cranes don't have any staging area in the spring. When they leave Texas, they get to Canada as fast as the winds and weather will allow them to go — a trip they can complete in 2 to 3 weeks. The Whooping Cranes that migrate between Florida and Wisconsin also have a rapid journey that they can sometimes complete in 10 days.

Some Good Questions
Once North America had as many as 10,000 Whooping Cranes but they declined to no more than 1,400 birds by around 1870. By 1941 the number fell to an all-time low of 21 birds.

  • Why are there over 600,000 sandhill cranes in the Central Flyway and only 237 whooping cranes?
  • Why has the sandhill crane been so successful?
  • Why, of the 15 crane species in the world, are most of the ones that are white in color the most endangered?
Jot ideas in your journal. Then see what I think. >>

An Important Step Taken
One of the most important steps in saving the Whooping Crane was the protection of their summer and winter homes. The Wood Buffalo National Park in Canada was established in 1922, and Aransas was protected from 1937.

Today, a majority of the mortality of Whooping Cranes occurs during migration. That is why it is so important to learn as much as we can about what they need to successfully complete their migration. You can help by spreading the word and telling what you know!  

Tom Stehn
Whooping Crane Coordinator