In this week's whooping crane report you'll find:
* News from the cranes' wintering grounds in Texas, by biologist Tom Stehn.
* Reports of sightings along the migration route, collected by biologist Wally Jobman.
* In a separate message, news about the 1000 Crane Club, a club featuring cranes as a symbol of peace.
Remember, you're invited to Ask the Expert by sending your questions about whooping cranes to:
Here's the news from Texas:
"Dear Students,
"I've been so busy that I didn't have time to write last week. I did an aerial census flight on April 18th to count cranes and could only find 10. That means that 62 whoopers started migration between April 6th and April 17th. (Previously, 60 cranes had left between March 23rd and April 6th.) The cranes leave in small groups, often just two or three birds together.
"The 10 birds still here at Aransas are all young cranes, less than 3 or 4 years old and not old enough to breed. We refer to them as subadults. They aren't in any hurry to return to Canada since they will not nest, but they still make the journey . Isn't it amazing that even the subadults will travel 2,500 miles back to the nesting grounds in Wood Buffalo National Park, Northwest Territories, Canada every summer?
"The Nyarling pair left on April 7th. I often says cranes migrate during "banker's hours", roughly about 9 AM until 4 PM. They normally wait until mid-morning to start a migration flight. This is when thermal currents are available for them to soar upwards, up to a mile high in the sky! Why do you think these currents are advantageous to crane flight? And why do you think cranes usually fly just during daytime and not at night? Often, when winds are blowing from the north, the cranes will not migrate and stay wherever they happen to be for several days at a stretch. Why do you think that makes sense for the cranes?
"Reports are coming in on cranes in the flyway. There have been reports from Kansas, Nebraska and South Dakota. Seven birds were together in a group near Pierre, South Dakota on April 16th. I'll bet that those seven cranes did not fly together all the way from Aransas though. Instead, two or more groups of migrating cranes probably crossed paths somewhere on the journey and spent some time together.
It fascinates me that each crane pair seems to have its own clock and timetable. I remember one spring when two teams of biologists were following two separate cranes by radio transmitter. Even though the two cranes had left Aransas two days apart, they crossed the Canadian border within 30 minutes of each other! However, one of the birds then landed and stayed in Saskatchewan prairies for a week while the other crane apparently continued straight on to Wood Buffalo.
"I'll be continuing to watch the cranes here to learn when the last 10 birds finally leave for Canada. I know the Canadian biologist who studies cranes plans to be in Wood Buffalo Park on April 28th and will start searching for nests. I hope there is lots of water on the nesting grounds this year. More chicks are able to survive when the marshes are full of water.
"Please help me wish for a successful breeding year for the whoopers. Id' really like to see our flock of 133 birds grow back up to the record 146 birds that we had in the 1990- 1991 winter.
"Cheers,
Tom Stehn/Refuge Biologist Aransas National Wildlife Refuge"
Here's Wally Jobman's report from Nebraska:
"Dear Students,
"The weather in the Northern Great Plains was once again a big factor affecting the whooping crane migration during the period of April 15th-21st. The most favorable migration days were April 15th and 21st. Moderate to strong north winds (gusts up to 50 mph), rain, thunderstorms and snow prevailed on the other days. Heavy windblown snow (1-3 feet) in northern Nebraska and eastern South Dakota fell on April 17th and 18th.
"Included in the sighting from Kansas was the first color- banded bird reported. The bird had a red band on each leg, which tells us it was banded as a chick in Canada in 1988. It has an unbanded mate and is expected to nest this summer.
"Two sightings of 2 birds each have been confirmed thus far in Saskatchewan, Canada. Both sightings were made on Easter weekend (April 15th & 16th). One was near Govan, Saskatchewan and the other was near Luseland."
Wally Jobman U.S. Fish & Wildlife Service Grand Island, Nebraska
Date # Sighted Location April 14 2 Gibbon, Nebraska April 15 1 Govan, Saskatchewan April 16 1 Luseland, Saskatchewan April 16 7 Hayes, South Dakota April 16 3 Ford, Kansas April 17 2 Holdrege, Nebraska
Journey North 125 North First Street Minneapolis, Minnesota 55401 Phone: (612)339-6959