Meet Tom Stehn

April 6, 2006

Dear Journey North,
The whooping crane migration has really gotten underway in a big way. In the past week, an estimated 61 whooping cranes have headed north. They are goint to Wood Buffalo National Park in the Northwest Territories of Canada. The nesting area is north of Aransas by 2,500 miles. So far this spring, 77 cranes, or 36% of the flock of 214, have migrated. The only migration sighting reports yet are from the Platte River in Nebraska, and one sighting April 5 from South Dakota. That should change this week, as I expect reports to start coming in from the 7 states in the whooping crane migration corridor. Can you name those 7 states? Do you live in one of them?

The Numbers
I had an exciting census flight on April 5th. By the end of the day, I estimated 61 cranes have started the migration since the previous flight on March 29th.

Watching Cranes Leave: An Exciting Flight
On today’s flight, we observed a pair of cranes flying from the marsh towards a fresh water pond, presumably to get a drink. But the pair kept flying past the pond. They seemed to wander aimlessly, flapping and spiraling around in circles. But soon the pair had gained altitude and was at 1,000 feet. We quickly climbed above them in the airplane to keep them in sight. We then noticed a second pair of cranes flying much lower down about 1⁄2 mile away from the first pair, but also flying in a spiral pattern.

So now we had two pairs to keep an eye on. They weren’t really making any progress, but soon the pair that was higher started making progress to the northwest as they glided down a little. The second pair caught up to them, but was still about 500 feet lower. What a sight to see their huge 7.5-foot white wing span with black wing tips, working hard to climb but also resting a lot as they spiraled up. They seemed to be flying in and out of shade from puffy white clouds high above them as they searched for thermal currents. After about 10 minutes, the two pairs had covered about 5 miles and were more than half way across the Aransas refuge. It was clear they had started the migration. We wished them well and headed back over the marshes to continue our census.

Later, we re-flew portions of the refuge and estimated at least 10 cranes had started the migration that morning, all from the same general part of the refuge. What a privilege it is to be able to watch a bird start migration. They have so far to go!

Meet the Long Reef Family
A family group of whooping cranes was on the Platte River April 1-4. One adult had a green band on the left leg. On today’s census flight, I tried to find the three cranes at Aransas with green bands. I found two out of the three; thus I knew which birds had been on the Platte River. We notate this banded adult crane as "Green-high silver" since it has an aluminum band on the right leg and a large green plastic band on the left leg. The banded bird was a juvenile in 1988. This makes him 18 years old. But here's the amazing thing: I saw this bird at Aransas early on the morning of March 29th on their winter territory located next to Long Reef on San Jose Island. That’s my name for this family: the Long Reef family. On the afternoon of April 1, this family group was on the Platte River in Nebraska. They had traveled all that way in just 4 days!

Good Conditions and Two Questions
Conditions for starting migration have been very good throughout the past week. April 1 and April 5 were especially good, with strong southeast winds gusting up to 30 mph. These tailwinds provide the cranes a helpful push, making their flight much easier. The cranes also rely on thermal currents. They climb way up—as high as one mile—using their huge wings to be lifted up on thermal currents.

My Prediction:
I expect another 75 or so whooping cranes to start the migration this coming week. The migration seems right on schedule!

Tom Stehn
Whooping Crane Coordinator
USFWS

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