Tom Stehn's Report: They Know When to Go
March 25, 2011
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As you read Tom's report this week . . .
  1. When do most Whooping cranes usually leave Aransas?
  2. Are any of the birds from the Western flock migrating?
  3. How do migration departures the past two years compare with previous years?



Adult and juvenile danciing
Image: Klaus Nigge

Dear Journey North Kids,

Every spring I see the palm trees bent over by strong coastal winds, yet the whoopers stay put until late March. So give the cranes another week and maybe we'll start seeing some movement the last few days of March and first week in April. They have evolved not to leave Aransas too early or they will encounter frozen landscape when they get into the Dakotas. So they've evolved to start the migration when the days get to be a certain length in the spring. I'm always amazed how a bird can tell that the days are getting longer, but somehow they can.

Timing: Is It Changing?
Stationed in Nebraska with the USFWS, Jeanine Lackey reported a pair of birds was confirmed in Kansas on March 16, and by March 22 she confirmed a group of four and another twosome. A single was also confirmed in Nebraska. Until last year, the general "rule" was that very few Whooping cranes ever started the migration before March 25th. But that may be changing. Last year (2010) the first Whooping crane had departed the Texas coast by February 23rd, a very "early" record. Between March 16 and March 23, another 12 Whooping cranes had been reported spread between Texas and Nebraska in the Central Flyway. There were a few early starts this year, too.

What do you think will happen next? I'll have more news in a week!

Tom Stehn, Whooping Crane Coordinator
Aransas National Wildlife Refuge
Austwell, Texas