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 December 16, 2002 of the Aransas National Wildlife Refuge and surrounding areas estimated the number of whooping cranes present at 166 adults + 15 young = 181 total. One juvenile has died since arriving at Aransas, making the peak population for the 2002-2003 winter 166 + 16 = 182. The peak population consisted of 132 adults, (maximum of 66 pairs or potential pairs), 34 subadults, and 16 chicks.
Recap of cranes observed: (181)
adults + young
Refuge 48 + 6
Lamar 4 + 0
San Jose 42 + 2
Matagorda 52 + 6
Welder Flats 20 + 1
Total 166 +15 = 181
The 181 crane total is an increase from the 173 cranes present in the spring, 2002. The all-time high for the Aransas/Wood Buffalo flock was 188 in the winter of 1999-2000.
A. I concluded there was no duplicate count of the trio on today's flight, with 181 cranes observed. A trio was sighted on San Jose Island and then replaced geographically by the territorial Spalding Lake pair. We did not find where this trio moved to. After speculating that the trio had split into a single and a duo east of Spalding Lake, comparison with the crane distribution on last week's flight made this seem less likely.
B. The presence of 4 subadult cranes and two territorial pairs on the south end of Matagorda Island in locations nearly identical with last week led me to conclude that there had been no count duplication last week in the area of Bray's Cove. Thus, the count on last week's flight (179) was increased by 2 and matched the 181 cranes observed on today's flight.
Remarks: Mostly clear skies throughout the day provided excellent viewing conditions. All of the crane areas except for Indianola were covered in 8.0 hours of flight time.
The distribution of cranes was similar to last week, lending confidence to the designation of territories and the population estimate. All territorial pairs were found both weeks. The number of subadult cranes (34) increased from last week by 2 on San Jose and 1 on Matagorda, and decreased by 2 on Welders and 1 on the refuge, for no net change. The presence of two fewer subadults on Welder Flats was surprising after two consecutive weeks with 23 cranes present.
A pair was found for the second straight week in the Jay Bird Point territory. However, there was definitely no band present above the foot of the male. Thus, either the band has fallen off, or the Jay Bird Point male died subsequent to nesting in 2002. The bird with a drooping left wing was observed in a duo near the airstrip on Matagorda Island, with the wing not hanging all the way to the ground as was observed 3 weeks ago.
Habitat: Only the marshes on San Jose still had extensive mudflats, with about half of the tidal flats showing exposed mud. The cranes are feeding on wolfberry and crabs, with several of the whoopers observed holding crabs in their beaks. However, a population count done December 13th found noticably decreased numbers of blue crabs and wolfberries compared to 3 weeks ago. Nine cranes were located in open bay habitat on today's flight. No cranes were on uplands or at sources of fresh water.
- Tom Stehn
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Patty Waits Beasley
Corpus Christi, TX