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Greetings all!

The following report is forwarded with permission from Tom Stehn, USFWS biologist and US Whooping Crane Coordinator.

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An aerial whooping crane census was conducted April 10, 2008 at the Aransas National Wildlife Refuge and surrounding areas.  A total of 34 whooping cranes were located.  The rest of the flock has started the migration. 

 

The estimated size of the flock remains a record 266.  The flock consists of an estimated 144 adults, 83 subadults, and 39 juveniles.  There is no evidence of any whooping crane mortality having occurred this winter.

 

Recap of cranes found at Aransas (34):

 

 

 

Adults + young

Refuge

    12 + 0

Lamar

      2 + 0

San Jose

      7 + 0

Matagorda

      9 + 0

Welder Flats

      4 + 0

Total

    34 + 0 = 34

 

              

The whooping crane survey was conducted in a Cessna 210 piloted by Gary Ritchey of Air Logistic Solutions of San Antonio, Texas with USFWS observers Tom Stehn and Darrin Welchert.  The 3-hour flight covered nearly the entire wintering area, but the wide transects flown may have resulted in a few cranes being overlooked.  Census conditions were okay with sunshine, but were very hazy which limited visibility.

 

I estimate that 87% of the whooping crane flock has started the migration.  Seventeen groups of whooping crane have been reported so far all the way from central Texas to South Dakota.  Most sightings have come from Kansas and Nebraska.  It is interesting to note that the cranes currently as far north as Nebraska will be held up by a snow storm and unfavorable winds in that state over the next few days.

 

At Aransas, all 34 cranes still present may be subaults.  In only one instance was a duo seen on Ayres Island that could have been an adult breeding pair.  Thus, the breeding pairs have started the migration earlier this year than in years past, since frequently some adult cranes donít start the migration until mid-April.  I think this earlier migration may be tied to the good food resources available to the cranes throughout most of the winter, leaving them in good condition to start the migration.  The pre-migration body condition of the cranes at Aransas is very important since the 3-4 week migration to Canada will not include much feeding, and conditions may be still very cold with only limited food available when they first reach the nesting grounds. Migration is generally a hard time for wildlife species with long-distance movements allowing little time to find food to eat.

 

The family group of territorial cranes seen all winter from the refuge observation tower has apparently started the migration.  On the flight, 31 cranes were in salt marsh habitat and 3 cranes were on an upland island on San Jose Island that is surrounded by marsh.  No cranes were on prescribed burns or at fresh water sources.  Tides were moderately high, with flooded marsh seen on the Lamar Peninsula, but average conditions seen on San Jose.  The water on the gulf beach was nearly up to the dunes with little beach exposed.

 

The next census flight is scheduled for April 22.

 

 

Tom Stehn, Whooping Crane Coordinator
U.S. Fish and Wildlife Service
Aransas NWR
P.O. Box 100
Austwell, TX 77950
(361) 286-3559 Ext. 221
fax (361) 286-3722
E:mail: tom_stehn@fws.gov

 

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Where applicable, CWS stands for Canadian Wildlife Service; USFWS is US Fish and Wildlife Service. Crane monitoring involves cooperative efforts and support by both countries, plus many volunteers and non-profit organizations along the way.