Whooping Cranes return to Texas Coast
The majority of the Canada/Texas Whooping Crane population has recently arrived at their winter home along Texas coast.
The following report was provided by Tom Stehn, USFWS biologist and U.S. Whooping Crane Coordinator.
"An aerial census was conducted on 08 November, 2007 of the Aransas National Wildlife Refuge and surrounding areas. The total number of Whooping Cranes located was 211. I estimate that approximately 80% of the flock has completed the migration with 30-50 whooping cranes still in the flyway.
Recap of cranes found: (211)--Adults + Young
56 + 10
6 + 1
44 + 5
59 + 9
16 + 5
181 + 30 = 211
Remarks: Flight conditions were very good with skies mostly sunny,
moderate southeast winds, and good visibility. The flight was conducted by
Pilot Gary Ritchey of Air Transit Solutions, San Antonio, Texas. The
5-hour flight was conducted in a Cessna 210 with Tom Stehn and Darrin
Welchert as observers.
This was the first aerial census of the fall. Prior to the flight, reports from staff, volunteers, and landowners had recorded as of November 2nd fifty cranes present (a minimum number). Many additional cranes arrived following a strong cold front that reached the Texas coast the morning of November 5th. This large arrival is right on schedule since the majority of the whooping cranes always seem to arrive with an associated front during the period November 4-7.
The 30 chicks currently present are an indicator of good survival subsequent to mid-August surveys done in Wood Buffalo National Park. Of the 13 chicks from pairs where both summer and winter territories are known, 12 of the 13 have made it to Aransas safely. The 13th family group is not at Aransas and presumably still in migration.
Results from the flight found one evidence of mortality. Present on the Narrow Peninsula territory at Welder Flats was a single adult with one chick, evidence that an adult had died subsequent to nesting.
Several territorial encounters were observed during the flight as newly arrived pairs staked out their winter territories. One notably large group of 9 cranes split up into groups of 2, 3 and 4 that apparently was a territorial pair showing aggression against subadults.
Recent habitat surveys indicate abundant blue crabs in the marshes and multiple wolfberry flowers that will soon be producing fruit. Salinities are quite moderate at 8-10 ppt. On the flight, no cranes were found on uplands, prescribed burns, or fresh water sources. Prescribed burns were done on November 7 and 8 on the extreme north end of Matagorda Island. Two cranes were standing on a shell road.
One worry about the habitat is the increasing amount of mangrove bushes proliferating on the northern part of the crane range on Matagorda Island. Mangrove is killed by hard winter freezes and its range has for decades remained south of the whooping crane range. With ongoing global warming, the range of the mangrove will likely move north and decrease the value of the salt marsh for whooping cranes.
Cedar Bayou is very close to becoming completely silted in. This bayou between the Gulf of Mexico and the bays within whooping crane critical habitat is important in the life cycle of many marine organisms, including the blue crab. Photographs were taken on todays flight. The bayou apparently was shut or very nearly shut during August, 2007. Studies are ongoing to assess environmental impacts for a proposed dredging project to increase flows in Cedar Bayou."
Tom Stehn, Whooping Crane Coordinator
U.S. Fish and Wildlife Service
P.O. Box 100
Austwell, TX 77950
(361) 286-3559 Ext. 221
fax (361) 286-3722