Tom Stehn's Report: Leaving Mom and Dad
Feb. 27, 2009
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Meet Tom Stehn
Whooping Crane Coordinator, U.S. Fish and Wildlife Service

As you read Tom's report this week, look for answers:
  1. At what times does a juvenile crane usually separate from its parents?
  2. What does Tom think caused some juveniles to separate early from their parents this winter?
  3. How do whooping cranes stay safe from predators when they are sleeping at night? How would a whooping crane be able to fight off something as big as a coyote?
  4. How did instincts help a young crane who still had more to learn from his parents?


Dear Journey North,

Juveniles still have some rusty brown feathers.

Photo:Diane Loyd

An important and dangerous time in the life of a whooping crane is when the juvenile (a bird less than 1 year old), separates from its parents. This separation usually occurs in late May, just before the parent cranes re-nest in Canada. Biologists have even observed the adult cranes showing their youngster a suitable marsh near their nesting territory and dropping off their juvenile before they settle to defend their nesting area.

Occasionally a juvenile will separate from its parents in Saskatchewan during the spring migration. Sometimes this happens before the family returns to Canada. Sometimes an adult pair will start the spring migration from Aransas and the juvenile stays behind. It can even occur sometimes during the fall migration. For some unknown reason, “junior” gets left behind as its parents continue the migration all the way to Texas. This is a very dangerous period since the youngster no longer has its experienced parents there to watch for and guard against predators. How do whooping cranes stay safe from predators when they are sleeping at night? How would a whooping crane be able to fight off something as big as a coyote?
How do juveniles cope without their parents to help them? This week I'll tell some real-life stories that help us explore these questions.
The Lone Nebraska Juvenile: A Happy Prediction >> Mohawk's Story: Unknown Fate. >> Two Unlucky Juveniles >>

I think something about the food shortages this winter are causing the juveniles to separate from their parents. A photographer noticed one juvenile whooping crane getting attacked by a neighboring pair of cranes. The parents of the adult flew off and away from the aggressive neighbors, but apparently the juvenile was too weak to fly. Although the juvenile was not injured in the attack, it was no longer with its parents and too weak to fly. A predator killed it that night. I found the carcass. Tests indicated the juvenile was starving and very thin, but the health experts could not tell me why or isolate a disease that the crane may have had.

So far this winter, 9 juvenile whooping cranes and 3 adults have died at Aransas. I’ll try to find out on my next census flight if any more of the whooping cranes are missing. This is a horrible winter for the cranes. But they are a long-lived bird, and most of the flock will survive these tough times! (And when you read Scarbaby's Triumph, you'll know there's still good news happening.)

Tom Stehn
Aransas National Wildlife Refuge
Austwell, Texas