Whooping Crane Migration Update: April 26, 1999
Today's Report Includes:
Whoopers Bid Farewell to Texas
The cranes have all left their winter home at the Aransas National Wildlife Refuge in Texas. Crane biologist Tom Stehn writes:
April 22, 1999
Dear Journey North,
We did nearly four hours of flying yesterday and we didn't find any cranes. The forty-one whooping cranes present on April 15 had apparently all started the migration. The past few days, winds have been howling from the south, providing the birds strong tail winds. Also, sunshine has provided the thermal currents that aid the birds flight by allowing them to spiral up to about a mile in altitude and then glide at up to 60 mph to the north. By taking advantage of these thermals and tailwinds, the birds really don't have to flap their wings that much which saves them energy.
Although migration conditions were ideal, I'm still surprised that a few of the non-breeding whoopers (ages 1 to 3) weren't still around. The past few years, a few whoopers have been lingering at the refuge until the end of April or even the first week in May. The fact that they apparently are all gone makes me think the migration on average was about one week ahead of normal this year. I'm going to do one more short census flight next week just to be sure I didn't overlook some.
Mixed Feelings and Planning for the Future
I'm always excited when the birds migrate because this is a 2,500-mile journey the birds must make for the population to grow. I am already hoping for a good nesting season and looking forward to counting the parents with their young when they return in the fall. The cycle continues, and overall the population has been growing about 4 percent annually. This is the time for hope and big expectations for that record nesting season!
Cranes Coming and Going through Nebraska
Biologist Wally Jobman reports on the migration between Texas and Wood Buffalo National Park.:
Monday, April 23, 1999
April 18-20 should have been a good migration period since it was warm with south winds. Cloudy, cool, damp weather moved in on April 21 and continues today. Heavy snow in northeastern Colorado and southeastern Wyoming began falling on April 22, but no snow in the migration corridor. I am hoping for additional sightings in Nebraska, but it may not happen.
Enclosed is a list of sightings reported to me since my April 19 report. I have North Dakota records beginning in 1955, and the sighting in Sargent County, North Dakota was one of the farthest east sightings confirmed since 1955 (i.e., only one sighting farther east).
Challenge Question #11
"What are some of the hazards that Whooping Cranes face on their long flight between Aransas National Wildlife Refuge and Wood Buffalo National Park?"
Cranes Welcomed to Canada
The first Whooping Cranes passed through Wally Jobman's area and have arrived safely in Canada! Biologist Brian Johns writes from Saskatoon, Saskatchewan:
Dear Journey North:
As you know Whooping Crane migration is in full swing and Tom's report from Aransas indicates that they have all left the wintering grounds. The first report of cranes in Canada was on April 9. To date we have had sightings from southern Saskatchewan and also southwest Manitoba. The Manitoba sighting is unusual in that birds are not usually that far east. It may be related to the strong winds that blew those six cranes into Iowa in early April.
Meeting an Old Friend
The pair that was sighted in Manitoba was there from April 14th to the 17th. One of those birds had a Green-white-Green band on the left leg. The banded bird is a male who was originally banded with a Green-white-Green band on the left leg and a Yellow-black-Yellow band on the right leg. GwG-YbY was hatched in 1987 in the Alberta portion of Wood Buffalo National Park. GwG-YbY and his unbanded mate established their territory in Alberta and have nested since 1993. Unfortunately they have not yet been successful in raising a chick. Lets hope that 1999 will be the year that this pair is successful.
On April 21 a group of 4 cranes were sighted near the middle of the province of Saskatchewan. From there it is only about a 2 or 3 day flight to the nesting grounds. On April 23 one of the wardens from Wood Buffalo National Park, flew over the nesting area and observed 4 pairs of Whooping Cranes on their territories. GwG-YbY and his unbanded mate made up one of those pairs. Upon arrival the cranes usually take a few days to checkout the territory they held last year before selecting a place to nest. None of the 4 pairs had started nesting so they had likely just arrived.
Spring Comes Early
Spring has come early to the crane marshes with daytime temperatures this past week around 15 degrees Celsius. It has been so warm that the Red-sided Garter Snakes began coming out of their winter dens on April 13th, which is about 10 days earlier than normal. The Sass River and Preble Creek, two of the major streams that flow through the Whooping Crane breeding area, are already ice free and flowing. In some years these creeks are still frozen solid even into the first week of May.
Canadian Wildlife Service
How to Respond to Today's Challenge Question
1. Address an e-mail message to: email@example.com
2. In the Subject Line of your message write: Challenge Question #11
3. In the body of your message, answer the question.
The Next Whooping Crane Migration Update Will be Posted on May 3, 1999
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