December 5, 2008
The third aerial census of the 2008-09 crane season was conducted December 5, 2008 in a Cessna 210 piloted by Gary Ritchey of Air Transit Solutions of Castroville, Texas with USFWS observers Tom Stehn and Carey Strobel. Visibility was difficult for finding cranes due to heavy overcast skies during the 8.0-hour flight. Located were 198 adults + 31 juveniles = 229 total. This was 37 fewer cranes than the previous flight conducted November 25th.
Recap of cranes (229) found at Aransas on the aerial.
| |Adults + young |
| Refuge | 54 + 11 |
| Lamar | 6 + 3 |
| San Jose | 43 + 4 |
| Matagorda | 79 + 11 |
| Welder | 16 + 2 |
| Flats | |
| farm fields| - |
| Total |198 + 31 = 229|
Explanation of numbers
Experience indicates that only 85-90% of the flock can usually be located when skies are a thick overcast. This was definitely the case on today's
For the second week in a row, only 2 family groups were located on Welder Flats. This makes me postulate that the 4 family groups seen at Welder Flats on the November 14th flight may have cranes that had recently arrived that later moved on to other parts of the crane range. Thus, I cannot add two family groups on to the estimated flock size as I had done after the November 25th flight. Therefore, the current estimated flock size is 230 adults + 40 juveniles = 270. Those numbers are NOT firm and are lower than my previous estimate of 275. Future flights will focus on determining the number of juveniles present and total flock size.
Migration sightings of a pair of cranes were as follows:
11/24 - pair last seen at Cheyenne Bottoms, central Kansas
11/28-11/29 - pair seen at Salt Plains in northern OK
12/03 - pair seen 4 miles north of Aransas in the farm fields
Given the group size and timing, I am guessing these could very well be the same pair tracked across 3 states.
The solitary juvenile crane that had been near Alma in southcentral Nebraska near the Kansas border resumed migration on December 5th despite strong southwest winds. It had been at that same location since at least October 15, so it was not the juvenile from the family group reported in migration near Alma. The crane's roost pond froze up on the December 4th and presumably was a factor in the chick's decision to continue the migration. It has not been reported since it left Alma.
Sightings near Aransas
Whooping cranes are showing up in unusual places this fall presumably related to food shortages and the need to seek fresh water to drink. On December 5th around mid-morning, a single whooper was seen flying near Colomo Creek about 1/3 mile west of FM 1289. Coloma Creek empties into Powderhorn Lake and is located southwest of Indianaloa, Texas north of Aransas.
In the farm fields between Austwell and the refuge, whooping cranes have been sighted among the 600+ sandhill cranes utilizing different fields as follows:
group dates remarks
0+1 November 19 Decembeer 8 juvenile whooping crane by itself
4+0 November 10-14
1+0 November 18-20
2+1 November 23 presumed new arrival from the migration
2+0 December 2-8
2+1 December 9 new arrival or returnee from Aransas marshes?
Fourteen different whooping cranes have been seen at wild game feeders this fall. Locations of the feeders on private property include just north of the refuge headquarters, and three locations on the Lamar Peninsula.
Cranes on the flight included 24 observed at fresh water sources, 16 on burned uplands, 4 on unburned uplands, and 3 in open bay habitat. On a boat trip over to Matagorda Island on December 11th, I noted two pairs of cranes feeding in open bay habitat in Sundown Bay.
Items of interest
On December 1st, I picked up a very emaciated whooping crane from near a water hole by the refuge boat ramp. The crane could not stand and after capture was having difficulty holding up its head. The crane died while I was driving it to a veterinarian in Port Lavaca. The bird was shipped to the National Wildlife Health Center in Madison, Wisconsin and was necropsied the next day. The crane was a 2-yr-old subadult male, extremely emaciated, with a bad left knee. Organisms are being cultured from the knee to see if it was badly infected that could have been making the bird very sick and limiting its food intake. There was no other indication of disease, although additional tests are being conducted. A whooping crane was observed in Saskatchewan in the fall migration with a severe limp of the left leg and could well have been the bird that died at Aransas.
Food sources for whooping cranes seem very low this winter, primarily due to the summer drought. I expect to confirm a record number of whooping cranes at Aransas this winter, but the flock will probably experience additional mortality. A blue crab count conducted by refuge volunteer Katherine Cullen on December 1st found only 1 crab in an hour of walking through the marsh. However, observations by the tour boat captains the first week in December noted some blue crabs were still available for the cranes. Only a few wolfberry fruits and flowers were seen during the crab count. Follow-up searches for wolfberries conducted on Matagorda Island confirmed that this year's wolfberry crop was lower than normal. Tides have been lowered by recent low pressure systems, and bay salinities remain high at 30 parts per thousand. Cut-off marsh ponds had salinities levels of 43 ppt.
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