Western Flock News
April 24, 2009
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Meet Tom Stehn
Whooping Crane Coordinator, U.S. Fish and Wildlife Service
Western Whooping Crane Census Flight

Clear skies and moderate winds made April 21 ideal for conducting the eleventh aerial census of the 2008-09 crane season at Aransas. Gary Ritchey piloted a Cessna 210 plane with Tom Stehn aboard. They flew over nearly all parts of the crane's wintering range. Tom explains what they discovered.

Dear Journey North,

Here's what we learned about the migration:
Today's flight tallied 20 adult cranes plus 1 juvenile for a total of 21. That means that the other 91.5% of the flock has started the migration. That's 226 birds out of 247, and it includes all known adult pairs. Eighty-eight of these cranes began to migrate since the last census flight on April 7th. Whooping cranes in migration have recently been reported as far north as Saskatchewan, Canada. Some cranes probably headed north today since conditions were very good for migration with sunny skies and mostly southwest and south winds after several days of unfavorable migration weather.

Eight of the 21 cranes located on today's flight were singles. The one juvenile present was closely associated in a group with 3 white-plumaged cranes, the largest group observed on today's flight. The juvenile's parents presumably started migrating and left "junior" behind. "Will he be okay?" you might ask. This juvenile crane will be fine. It has the knowledge to make the return migration to Wood Buffalo National Park on its own or with other subadult cranes.

Whooping Crane Numbers
The current flock size is estimated at 225 adults + 22 juveniles = 247. The estimated peak winter flock size at Aransas was 232 adults + 38 juveniles (270 total), but there were some losses.

Habitat Use: A Changing Food Source
For the first time all winter, all the whooping cranes found today were in a salt marsh. The cranes are believed to be feeding on fiddler crabs since blue crabs in the marsh ponds are still scarce. This is due to the continuing drought. A blue crab count done on April 1st found zero crabs in the marsh. The refuge has discontinued its program of supplemental feeding with corn since most of the cranes have migrated.

A lightning-caused wildfire that started April 18th on Matagorda Island burned approximately 10,000 acres of upland prairie lands. The fire, located between Pringle Lake and Power Lake, was contained on April 20th and allowed to burn out. The burn will benefit the prairie habitat by recycling nutrients and controlling brush.

Tom Stehn
Aransas National Wildlife Refuge
Austwell, Texas

Meet Brian Johns
biologist, Canadian Wildlife Service

Dear Journey North,

Please check back soon for this report on the Canadian nesting grounds!




Brian Johns
Canadian Wildlife Service
Saskatoon, SK
Wood Buffalo National Park