Journey North Whooping Crane Spring 2005

Tom Stehn

Photo Heather Ray

April 6, 2005

Dear Journey North,

The whooping crane migration is underway with an estimated 61 cranes having departed the wintering grounds. This amounts to 28% of the flock. The cranes travel in small groups, often in groups of 5 or less. Single cranes sometimes even make the migration by themselves. Can you think of advantages for having the cranes migrate at different times and not in large groups?

The migration is right on schedule. I expect a majority of the remaining cranes to start the migration in the next 10 days. Weather forecasts look favorable on April 9 and 10 for migration. With west winds blowing April 6 and 7, the cranes will stay put until the winds switch around to the southeast and provide tailwinds to aid the cranes' trip north.

Below is my flight report from my 7-hour census flight on April 6. (It takes that long to cover the 35-mile stretch of coastal Texas marsh that the whooping cranes occupy during winter!)
___________________________
An aerial census on 06 April, 2005 of the Aransas National Wildlife Refuge and surrounding areas estimated the number of whooping cranes present at Aransas at 128 adults + 26 young = 154 total. The current estimated size of the Aransas-Wood Buffalo population is 182 + 33 = 215.

Recap of cranes observed on the flight: (154)
adults + young
Refuge 34 + 8
Lamar 3 + 1
San Jose 34 + 9
Matagorda 42 + 7
Welder Flats 15 + 1
Total 128 + 26 = 154

•Excellent viewing conditions were present throughout the day with a complete census flown. With winds from the west, no cranes are expected to start migration April 6 or 7.
•An estimated 61 whooping cranes (54 adults and 7 young) have started the
migration since the last flight on March 23.

•Three cranes were observed by a tour boat high over the refuge leaving in migration on April 3.

•Conditions were excellent for initiating migration on April 3-5. A few cranes also may have started migration on March 29 with favorable conditions present.

•The chick that wintered 75 miles north of Aransas was last reported in Texas on March 18. It was confirmed present on March 28th on the Platte River just east of Grand Island, Nebraska. Although this juvenile did not start the migration with sandhills, it had caught up to them on the Platte. After a stay of six days on the Platte, it was observed heading north on April 2. Six adult cranes were confirmed present in the Rainwater Basin, Nebraska on April 5-6.

•On today’s flight, tides were low and most cranes were in ponds or open water areas. Five cranes were in open bay habitat, all at Welder Flats. No cranes were sighted on prescribed burns or uplands. One subadult crane was located south of Holiday Beach. No cranes were found north of the former Bomber Base on the north end of Matagorda Island where a duo had been present on March 23.

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