Seventh Aerial Census of 2009-10 Conducted

The seventh aerial census of the 2009-10 whooping crane season was conducted March 9th, 2010 in a Cessna 210 piloted by Gary Ritchey of Air Transit Solutions of Castroville, Texas with USFWS observer Tom Stehn. Sighted on the flight were 193 adults and 18 juveniles = 211 total whooping cranes. Fog rolling in off the Gulf in the late afternoon prevented completion of the census. No evidence of mortality was noted on the flight other than the one juvenile that had died earlier in the winter. The flight again provided solid evidence of 20 family groups currently at Aransas. With one juvenile last seen in Oklahoma December 25th that apparently separated from its parents during migration and is presumably okay and wintering in an unknown location, and the S. Sundown Island chick that has died at Aransas, this accounts for 22 of the 22 juveniles found in Canada during the mid-August fledging surveys. With the one documented mortality this winter, the current flock size is estimated at 242 + 21=263.

March 9th – Recap of whooping cranes (211) found at Aransas:

[TABLE=9]

* Census incomplete due to presence of fog.

Some cranes continue to leave their marsh territories and are searching for food on the uplands. Upland areas on the barrier islands are flooded, with numerous wet swales on the uplands up to the beach dunes. Overall habitat use documented on the flight included 27 cranes on unburned uplands (13%, or half of the previous flight’s total), 2 in open bays, 3 at a game feeder at Welder Flats, 0 on prescribed burns, and 179 (85%) in salt marsh. Low numbers of 2-3 inch blue crabs have moved into the marshes with recent high tides, and more foraging on crabs has been noted, although blue crab numbers are still low.

Flight Conditions: Winds were light and flight conditions were smooth. Visibility was challenging throughout the flight due to all the moisture in the air. Late afternoon sunshine was often shining in our faces so that it was only possibly to see cranes reliable heading away from the sun. Late afternoon fog rolling onto the barrier islands prevented us from completing the census. The largest group sizes observed were 9 birds seen in the marsh on San Jose and 7 on the uplands on Matagorda Island.

Spring Migration, 2010

The single white-plumaged whooping crane confirmed present at Salt Plains NWR in northern Oklahoma on February 24th and 26th apparently moved on to the Platte River in Nebraska where it was confirmed on March 5th. No other whooping cranes are believed to have left Aransas.
– Tom Stehn, Aransas National Wildlife Refuge