March 26, 2003
The following report is forwarded with permission from Tom Stehn, USFWS biologist and US Whooping Crane Coordinator.
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.
Anyone wanting to contact Tom about the report or the whooping crane projects can reach him via email at firstname.lastname@example.org. Other information, including archived copies of these reports, can be found at the Texas Whooping Crane web site at http//www.ccbirding.com/
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An aerial census on March 26, 2003 of the Aransas National Wildlife Refuge and surrounding areas estimated the number of whooping cranes present at
156 adults + 14 young = 170 total. The flight indicated that as many as 14 of the flock's 184 whooping cranes had started the migration.
Recap of Cranes Observed
adults + young total Change from March 19
Refuge 40 + 4 = 44 - 6
Lamar 4 + 0 = 4 - 2
San Jose 34 + 2 = 36 - 6
Matagorda 58 + 7 = 65 0
Welder Flats 20 + 1 = 21 0
Total 156 + 14 = 170 - 14
Remarks and Conclusions Mostly clear skies throughout the day provided excellent census conditions. All areas were covered in 7.7 hours of flight time.
Today's flight indicated the spring migration had started with up to 14 cranes having departed since the last flight on March 19. They are believed to have started migration on March 24 or 25, the only days with favorable conditions for migration since the previous flight when all cranes were documented present. It is interesting that no cranes had migrated from Matagorda Island or Welder Flats, but cranes had apparently headed north from the Refuge and San Jose island.
Specifics / Interesting Locations An estimated 2 adults pairs, 1 family group, and 7 subadults were not found and presumed to have migrated. Gone
were the Mustang Slough, Middle Sundown Bay pairs, and the Lakeside family, all from the refuge. The S. Dunham Point pair had apparently returned to their territory after being off-territory for 2 consecutive weeks. Two subadult cranes were no longer south of Holiday Beach on the Lamar Peninsula. However, the Big Tree pair had flown across Lamar to that location. The chick that had separated from its parents on Matagorda continued to be closely associated with a subadult. A subadult with an injured wing was possibly located on the south end of Matagorda, but the wing was not drooping and thus the injured bird may not have been recognizable. It was believed present on Matagorda since the number of cranes present on the island remained unchanged from last week. The 65 cranes present on Matagorda Island ties the all-time high for that location with the record set last week.
The number of cranes on Welder Flats has remained notably consistent most of the winter at 21. Present are 1 family group, 8 pairs, and 2 subadults. The subadult cranes were seen on today's flight being chased by the Grass Island pair, and then shortly thereafter apparently displaced again by the Narrow Peninsula pair. These observations clearly substantiated my earlier conclusion that two subadults were present at Welder Flats.
Habitat On today's flight, no whooping cranes were in open bay habitat, on prescribed burns, at fresh water sources, or on uplands. Some cranes were foraging on crabs; others were in marsh vegetation. The refuge received more than one inch of rain the night of March 25th. Refuge swales were full of standing water, as wet as it has been all winter. Marsh salinities were measured at 8 ppt on March 24th, with bay salinities at 5 ppt. Crab counts completed on March 24 found an abundance of mid-size crabs in the marsh that should provide excellent foraging for the cranes as they prepare to migrate.
- Tom Stehn
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Patty Waits Beasley
Corpus Christi, TX