Tom Stehn's Report: Keeping Track
March 27, 2009
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As you read Tom's report this week . . .
  1. How is the leg band of a Whooping crane in the Aransas flock different from the leg bands on the cranes in the new Eastern flock?
  2. Why is Tom's main worry as the 2,500-mile migration is about to begin for the cranes at Aransas?
  3. Learn more about when banding of the natural flock was ended, and what banding studies have revealed. Cracking the Code: Banded Cranes Tell Their Story >>

Dear Journey North,

Migration news and my next census flight should be next week. For now I have something that may surprise you. Do you see an aluminum band on the right leg of the wild Whooping crane in this photo at Aransas?
This is a standard aluminum band used by bird banders across North America.The aluminum bands come in a range of sizes to fit everything from the size of a hummingbird or sparrow to something as large as an eagle or Whooping crane. Photo USFWS

The band is engraved with a multi-digit number. If the bird is captured or found dead and the band is recovered, data kept at the USFWS National Bird Band Lab at the Patuxent Wildlife Research Center would identify the bird by its band number. It would also tell when and where the bird was banded. Every bander is required to turn in reports of what they banded to the Bird Banding Lab.

Bands with radio transmitters were never used for tracking birds of the world's only naturally occurring population of Whooping cranes, but they are always used for the birds in the reintroduced Eastern flock. In fact, no birds of the Aransas/Wood Buffalo flock have been banded since 1988. (You can read more about what we learned from banding the wild birds and give a try at using the raw banding data with the help of another long-time USFWS scientist named Wally Jobman at this link.) As recently as 2007 we continued to learn about the life of a bird still wearing bands. And who knows what we may learn this spring if a banded bird is making yet another migration to the nesting grounds in Canada's far north? After the bad conditions at their wintering grounds here in Texas, some of the birds may be weak and malnourished despite the 13 feeders set on the refuge. They will soon begin the 2,500-mile migration, and I hope they are ready for the hard journey north.

Tom Stehn
Aransas National Wildlife Refuge
Austwell, Texas