Migration Halted as Whooping Cranes Decide to Stop Flying
Whooping cranes stand inside their pen during their journey south. Photo credit: Brooke Pennypacker, Operation Migration
February 3, 2012 – The migration of young whooping cranes following their light-sport aircraft "parents" to their Florida wintering grounds is over, even though the group is only in Alabama.
The decision to stop the migration was actually made by the birds, Joe Duff explained in the January 29 Operation Migration blog. They finally had good weather to fly, but the birds refused to follow their surrogate parents' leads.
So, at the February 1-2 annual meeting of the Whooping Crane Eastern Partnership (WCEP), the group decided to crate and transport the nine cranes by road this Saturday to the Wheeler National Wildlife Refuge in Alabama, about 45 miles from their current site. Once the Class of 2011 is there, they will be held in the top-netted travel pen until the WCEP team arrives with their permanent bands and they are attached to each crane. After a day or two for the birds to recover from being handled and to adjust to their new leg jewelry, OM's Brooke Pennypacker, who will be staying on site with them, will release the birds into the wild.
"Migration is triggered by stimuli that are still not understood, but at some point it ends," Duff wrote. "A period of sedentary behavior follows while they spend time foraging at their wintering grounds until that urge hits again for the return trip. Maybe we have stayed too long in Alabama and for them migration is over. Or, maybe they were just too long in one place. Maybe if we had a few flying days in a row to gain back their confidence, or maybe we just have a few too many aggressive birds with minds of their own."
No matter the reason, it was clear on their last attempted flight that the birds had enough.
"For no reason at all, they broke," Duff wrote in the field journal. "I intercepted them and they followed me back on course. I hoped it was only a momentary lapse into old habits - but they broke again - and again. When I would catch up to them and re-take the lead, it was always #7 leading the V formation. At one point, when I placed my wing in front of her, she opened her beak and jabbed the wingtip in an angry challenge for the lead. She would follow for a while as long as we were heading in the direction she chose, but even then she would break and take the rest of the flock with her in sheer defiance of the aircraft."
After 2-1/2 hours they gave up, bringing the cranes back to the pen one or two at a time.
"Whatever the cause, it is obvious we will not get these birds to Florida this year in time to acclimate them to the wetlands of St. Marks and Chassahowitzka," Duff said. "We have to admit that it is time to concede to the greater influence of nature, and for this year, stop trying to engineer a behavior we donít really understand."
The group started their trek from Wisconsin on October 9, 2011. But besides weather, this year's journey was hampered by the FAA, which grounded them in northwest Alabama while they tried to resolve whether or not OM's pilots were flying their certificated, N-numbered weight-shift trikes outside the sport pilot/light-sport aircraft regulations. The FAA granted a temporary exemption from the regulations in January, allowing the whooping crane flight to continue, and said they would work with OM to come up with a more permanent solution later.