Back on Territory!
Spring is the time that the previous years young strike out on their own. The juveniles spend their first winter with their parents and during spring migration or soon after arrival on the breeding grounds, they separate from their parents. Cranes do not tolerate other cranes on their territories--not even their own young from another year. If the young do not separate on their
One Procrastinator at Aransas
Find out the final score sheet from Aransas for the winter:
Wally Jobman in Grand Island Nebraska may have received his last whooper sighting for the year. He told us that
only one sighting has been reported since our last update: Four birds, observed April 21-27 in Hughes County, SD,
5 miles east and 3 south of Blunt, SD. Find it on the map and you'll see the whoopers are on the home trail.
Yippee! Hooray! Operation Migration Cranes Fly Away Home!
Are you wondering about the other two sandhill cranes that started out with Operation Migration but didn't return
with the flock? Cranes #8 and #13 may still make it. Crane #13 is the "fashionable late lady" that waited
until March 17 to depart Florida. These two are wearing solar radio transmitters that are not as effective as the
batter-powered units. Stay tuned to Operation Migration Headquarters (above) for breaking news!
A New Chapter in Whooping Crane History
The success of Operation Migration and the return of the sandhills is GREAT news for the endangered whooping cranes that we track each spring on Journey North. Why? The success of this migration experiment paves the way for the reintroduction of a second, wild, migratory flock of whooping cranes. This means all the eggs won't be in one basket, or all the wild whoopers won't be in the same location--a real risk for losing the entire population of this endangered species to a disease or a human disaster like an oil spill. At this writing, the USFWS is working to finalize a proposed rule that would designate whooping cranes in the eastern part of the continent (covering territory between Wisconsin and Florida) as "experimental nonessential" rather than endangered. Project personnel are hopeful that this reintroduction with up to 12 captive-bred whooping cranes will proceed in the fall of 2001. That means by fall, all eyes could be on Operation Migration with WHOOPING CRANES following the ultralight plane---another step in bringing this magnificent and ancient species back from the brink of extinction!
Nesting is Next: Dancing with Cranes
What would it be like to dance with a crane during these courtship rituals? George Archibald knows because he has done it--many times! Why? You'll find the story here, along with an answer to the question, "Do whooping cranes mate for life?"
Hey, Baby! The Next Generation
Each egg is cream or olive in color, marked with brown. (For great information about the nests and territory size, see the answers to Challenge Questions #17 and #18, below.) The eggs are large--about 3.9 inches or 98 mm long. They are also valuable, as cranes have just one brood each season. The male and female will incubate the eggs for 29-31 days. The inner membrane (the air cell) of a crane egg breaks about 10 to 39 hours before the baby cranes start pipping. As soon as the air cell breaks, the chicks start to make little sounds from inside their eggs! They make three different calls: contact, pipping, and stress. The chicks' parents purr, possibly responding to or stimulating, maybe even encouraging the babies to pip.
The chicks weigh an average of 114.2 grams when they hatch. It's a safe assumption that their rusty color (see photo) helps them hide more easily. What's next for the baby cranes?
What Babies Must Learn
We asked Brian what the young must learn from their parents. He replied, "Young cranes must learn many things. Some of the most important are:
It's a tall order! But with practice comes skill. Once they arrive in Canada, we wish this season's new crane
parents lots of success in nesting and raising their young!
Whooping Cranes for the Future
How many cranes will hatch and survive the summer breeding season? That's the news everyone is waiting for.
This is the last word from us on whooping cranes for spring 2001, but a new chapter is just beginning. As soon as pipping is heard from the whooping crane eggs chosen to be the new Operation Migration whooping crane flock, those eggs will need to get accustomed to the sound of the ultralight airplane that will "teach" them the migration route between the new wild flock's summer breeding grounds in Wisconsin and wintering grounds in Florida. If all goes according to plan, next spring (2002) we'll be watching in awe and wonder to see if the 12-or-so young whoopers return again to Wisconsin like their sandhill predecessors did this spring. They will repeat the migrations as they grow and mature until the age of about four, when they'll start laying eggs that will add more birds to the world's brand new wild flock of migratory whooping cranes. Even though the overall numbers were down this year, these are exciting times. You are witnessing whooping crane history in the making!
Talking About Territories: Discussion of Challenge Question #17
Last time Brian Johns told us the average territory size for a pair of cranes is about 5 square km. We asked, "How big is 5 square km? Name something familiar to you that is about the same size as a crane pair's territory."
Well, five square km is only about a sixth the size of Walt Disney World, but 8 or 9 times the size of Disneyland. That's a big territory! Here's another way to look at it. A robin's average territory is about half an acre. A whooping crane's territory of 5 square kilometers is 1235 acres. This means that 2470 pairs of robins could nest on the territory of ONE pair of whoopers!
Nice Nest: Challenge Question #18
Last time we explained how crane nests are built in water and are about 1 meter across. Some nests are built from the bottom of the pond up, while others are floating nests. The top of the nest is usually about 10 cm above the surface of the water. We asked, "Why do you suppose cranes build their nests as described above?"
Each pair of cranes builds their nest in early spring, and the nest has to stay high and dry for the entire nesting cycle. After laying the first egg it might be five weeks or more before the eggs hatch. After they hatch, the babies often sleep in the nest the first three or four nights after hatching. This all happens during the time of year when water levels fluctuate wildly from snow melt, spring rains, and even early summer droughts. In a driving rainstorm with high winds, waves of water can wash into a nest, dangerously chilling the eggs. So nests with the tops well above the water surface are most likely to be successful.
Year-End Evaluation: Please Share Your Thoughts!
Please take a few minutes to share your suggestions and comments in our Year-End Evaluation Form below. The information you provide at the end of each year is the single most important tool used to guide our planning.
It's a Wrap!
This is the FINAL Crane Migration Update for 2001. Thank you for joining in the excitement of tracking this magnificent bird's journey north! We'll be back next year to report on the summer breeding season, the journey south, and the exciting project to create a second wild population of migratory whooping cranes with an ultralight-led, escorted migration of captive-bred young whoopers. You won't want to miss a moment of this monumental year!
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