Tom Stehn's Report: A Big Week
April 20, 2007
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Meet Tom Stehn
Whooping Crane Coordinator, U.S. Fish and Wildlife Service

As you read Tom's report this week . . .
  1. How many cranes remain at Aransas NWR in Texas?
  2. What is very unusual about one of the cranes that's still at the refuge?
  3. How old was the crane that died in North Dakota?

  4. What did you like best about the life of the crane that died?
  5. How many cranes were found in each area of the wintering grounds? Go here to see>> and fill in your Aransas Departure Log >>

Dear Journey North,

We did a census flight over the refuge on April 19th. All but 7 of the 237 whooping cranes (3%) have started the migration from Aransas. I estimate that 65 birds started migration since the last flight on April 10th. Sighting reports in the migration corridor tell us that the Whooping Cranes are currently spread out across North America, and some have reached southern Canada.

All Juveniles Migrating
All the juveniles have departed Aransas. This includes the “twin” juveniles that had stayed behind when their parents left on migration. The cranes still at Aransas are all believed to be subadults, or non-breeders. Since they won’t pair up and nest in 2007, these birds do not feel the same urgency to pack their bags and leave the food-rich marshes of Aransas and face the long, hazardous trip north.

Healed Crane: No Urge to Migrate?
Three of the birds at Aransas may be the 3 cranes that failed to migrate north in 2006. Yes, they spent all summer at Aransas! One of the three suffered a severe injury as a juvenile in April, 2004. I think it was either bitten by a poisonous snake or was hit in the head with the talons of a raptor. The bird nearly died, with extreme swelling of the neck and head observed. The bird did not eat for up to 10 days. It spent lots of time sitting down in the marsh — something cranes rarely ever do. The crane got better and seems fine now, but somehow it seems that the urge to migrate was knocked out of it. I think the bird is a male. I wonder what will happen when it gets a mate — and the mate is in the habit of migrating. Who will the win the discussion about should we stay or should we head north for the summer?

"Senior Citizen" Bird Death on Migration
The total flock size was revised down on April 18 by one bird, (from 237 to 236 birds) when a dead Whooping Crane was found in a farm field in North Dakota. The cause of death was unknown, but it appears the bird had a broken neck. The bird will be shipped to wildlife health experts to see if they can figure out what happened. The bird had a red band on one leg. When photos of the band were sent to me, I identified the bird as r-Y, a male crane hatched in 1983, making it a very old bird. (How old?)

Besides its age, the bird was special for other reasons:

  • It first nested in 1986 and brought its first chick to Aransas in 1987. In 21 years of nesting, it successfully brought seven chicks to Aransas. It was still a very productive male, having brought six chicks to Aransas out of the last 10 years.
  • The dead bird and its mate both were equipped with radio collars in the early 1980s, recalled Stehn. “We called them the ‘radio pair.’ Not only did they produce seven offspring, but they provided us with a lot of valuable information about whooping crane movements.
  • It was involved in the fastest whooper migration across the United States ever recorded,” he related. In the fall of 1983, this bird and its parents were in a flock of six whooping cranes that landed near Pierre, S.D. on Nov. 8. They were found on the Texas coast just three days later.

Photo North Dakota Fish and Game Department
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Tom Stehn
Whooping Crane Coordinator