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 January 08, 2003 of the Aransas National Wildlife Refuge and surrounding areas estimated the number of whooping cranes present at 169 adults + 16 young = 185 total. This is a higher estimate for the peak population of the 2002-03 winter.
Recap of cranes observed: (185)
adults + young
Refuge 48 + 6
Lamar 6 + 0
San Jose 41 + 2
Matagorda 54 + 7
Welder Flats 20 + 1
Total 169 + 16 = 185
Remarks and Conclusions: Clear skies throughout the day and light winds provided excellent census conditions. All areas were covered in 7.8 hours of flight time except for Indianola and the northern end of Matagorda Island. Matagorda Island was flown starting at 0815 hours to take advantage of the excellent sun angle. San Jose Island was covered starting at 1415 hours with transects of 100 degrees flown to allow for viewing away from the sun and yet still have relatively long transects. This new strategy for the census flight worked extremely well. Thanks go to Pilot Tom Taylor for devising this strategy.
A total of 185 cranes was located. This is a new higher estimate for the peak population of the 2002-03 winter. On December 12th, a census flight had also located 185 cranes, but that day a trio was considered as a duplication, which in hindsight was erroneous.
The most surprising discovery on the flight was finding the 16th juvenile by itself on the northern end of the crane range on Matagorda Island. This chick had been missing since November 26th, not located on 5 consecutive flights, and had been considered dead. Perhaps the chick separated from its parents at the end of November, but it seems unlikely it would have left the census area. I have no explanation for why we did not find it on the last 5 flights other than we were looking for an intact family group.
The population of 185 consists of 134 adults, 35 subadults, and 16 chicks. Present are 67 nesting pairs or duos expected to nest in 2003. Note that this is a much higher estimate than the 55 known adult pairs present in Canada in 2002. The potential is high for more nesting to occur in Wood Buffalo in 2003 since this is the second straight winter with 67 pairs or potential pairs present at Aransas.
Specifics: The increase in cranes from last week primarily occurred on Matagorda Island. The 9 additional cranes located on Matagorda this week included:
3 - a trio on the south end, including a crane with a drooping left wing
2 - the Panther Pt. pair overlooked last week
1 - one additional subadult by Power lake
1 - one additional chick on Long Island west of Pringle Lake
2 - one extra duo on Long Island about 1 mile NE of the single chick.
This increase accounted for the huge difference from the 176 cranes located the previous week. Other changes from last week included 1 additional subadult onWelder Flats, and 1 less subadult on San Jose Island. The numbers on the refuge remained the same.
The crane with the drooping wing was re-sighted close to the Matagorda headquarters after having last been seen in mid-December, and not found on the previous two flights. The East Cottonwood family group does not yet have a defended territory and was found just south of Cottonwood Bayou. Two additional subadults were found north of Holiday Beach for the second consecutive week. The chick by itself and a duo about one mile away were both found on Long Island on the west side of Pringle Lake on Matagorda.
Only occasionally are wintering cranes found this far north on Matagorda Island. A band was seen for the first time this winter on the Vinson Slough pair. Present was an aluminum band above the left foot of one adult. The lower marsh water levels aided in seeing the band.
Habitat: The cranes were almost all in water areas, presumably feeding on crabs. A crab count conducted by refuge volunteers January 5th located 27 cranes in an hour of walking in the marsh. This is a notably high count for January, with temperatures unseasonably warm and the tides somewhat below mid-range, measured at 1.74 feet mean low tide. On today's flight, many cranes were in very small ponds with water levels that had declined, perhaps trapping prey. A surprising number of the whooping cranes were in mixed groups with other egrets, making it much more difficult to pick out the cranes. Eight cranes were in open bays, all at Welder Flats. No cranes were located in uplands.
- Tom Stehn
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Patty Waits Beasley
Corpus Christi, TX