Tom Stehn's Report: A Bit Unusual
March 26, 2010
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As you read Tom's report this week . . .
  1. What has been the general "rule" about the date when Whooping cranes start leaving Aransas in spring?
  2. How many Whooping cranes are probably still at Aransas?
  3. What might explain the unusual timing of departures this year?
What is Tom doing to help cranes? Hint: It's MUDDY! "I wish all ofyou could have been here to help," he says. See slideshow story.

Dear Journey North,

I am very disappointed I was unable to do a Whooping crane count this week because of mechanical issues with the census airplane. I will be grounded for the next few weeks until the plane can be repaired.

I think something a bit unusual is going on this spring. Prior to this spring, the general "rule" is that very few Whooping cranes ever started the migration before March 25th. This year just seems to be different. It seems like a considerable number of whooping cranes have started the migration earlier than normal. 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 have been reported spread between Texas and Nebraska in the Central Flyway. However, there are still a lot of whooping cranes at Aransas, probably more than 200.

I can only guess why some of these cranes left Aransas a bit early. I think food resources were not very good at Aransas this winter and spring, so there were no scrumptious meals holding the cranes at their winter home. So some of them are already on their way to Canada.

QUESTION: Can you think of reasons why it might be an advantage for whooping cranes to (1) migrate in small groups and (2) leave at different times?

Tom Stehn,Whooping Crane Coordinator
U.S. Fish and Wildlife Service
Aransas National Wildlife Refuge
Austwell, Texas