Update from the Whooping Cranes' Winter Headquarters
I felt fairly confident that one territorial pair was definitely missing and may have started the migration. In all, an estimated 10 whooping cranes may have departed the wintering area and headed north. I won't know for certain until I get to fly next week and see if I had simply overlooked finding some of them. Of course, the best way of knowing that the whooping cranes have migrated is if someone spots them in the flyway and calls in to report them. This was the case with 3 birds reported in Wildarado, Texas (close to Amarillo) on February 27. Whooping cranes normally don't start the migration until the last week in March or first two weeks in April. It would be unusual if 10 whooping cranes have started north this early. However, food continues to be short here at Aransas. The blue crabs just aren't available for the cranes to eat, so they are forced to eat clams. Imagine swallowing clams whole and relying on your gizzard to grind up all that shell and salvage a little bit of nutrition from the little piece of meat inside a clam! Are you ready for a discussion question? If foods are short on the wintering grounds and the whooping cranes are not getting enough nutrition (as is the case this year), in what way will the migration be affected? a) The birds will leave early hoping to find more food during the migration. b) The birds will leave late since their energy reserves are not sufficient for the trip. c) The birds will leave on time since the migration is governed by daylength and not food. d) Some of the birds won't migrate at all due to illness. I'm not sure anyone knows the answer to this question. But I'll try to provide some thoughts on it in my next report. Tom Stehn, Whooping Crane Coordinator U.S. Fish and Wildlife Service Aransas NWR P.O. Box 100 Austwell, TX 77950 Copyright 2001 Journey North. All Rights Reserved. Please send all questions, comments, and suggestions to our feedback form
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