Practice Makes Perfect
An unexpected outcome of the ultralight plane flights is that these flocks, known as the Eastern Migratory Population, are the most intensely monitored birds in the world. And the wealth of data gleaned from the monitoring is making it possible for researchers to tease out answers to fundamental questions about bird behavior.
This past year, biologists from the University of Maryland confirmed not only that whooping cranes learn from one another during migration but also the degree to which they learn. For example, their analysis showed that young cranes that migrate with older birds stay the course better than those who fly with flocks their own age. Rather than deviating an average of 60 miles, 1-year-old birds that fly with at least one older bird stray an average of only 40 miles. Further, the birds got better each year until they were 7 years old, with an overall improvement
of 38 percent.
“If you look at individual age, that doesn’t explain how well or how poorly they do,” says Thomas Mueller, an ecologist at the University of Maryland and lead author of the study. “Even if they are young, if they fly with an older bird, they do better.” Because the researchers also controlled for genetics, he says, learning was the only possible source of the improvement.
Granted, this learning is more akin to how young children watch older kids on the playground and imitate them versus an intentional effort to pass on knowledge. The latter only happens between whooper parents and their offspring, which may help explain why captive-raised cranes breed poorly. (In 1976, Archibald became famous for dancing with a captive whooping crane to inspire it to breed.) Although the adults are laying eggs, their success in rearing their chicks is tenuous. Some of the secrets of parenting, Mueller says, may need to be relearned. And as with migration, that may take time.
Other examinations of the data show that the whoopers in the Eastern Migratory Population are also demonstrating a surprising degree of adaptability. Instead of making a beeline to Florida, some are wintering anywhere from Tennessee to Alabama to South Carolina. “And these areas aren’t brackish water wetlands at all [like those chosen by wild whooping cranes],” says Archibald. “These are freshwater wetlands with lots of agricultural fields around them, which is completely different from what the wild birds are doing.” The wild flock is expanding its range some, too, however. Scientists believe this could be a positive development for the continuing recovery of the wild flock, since expansion into new areas may provide additional security if a catastrophic event such as a late-season hurricane were to impact refuge areas.
This year’s clutch of ultralight plane-led juveniles arrived at Florida’s St. Marks National Wildlife Refuge on Jan. 4, after 96 days en route. Inclement weather had grounded them for days on end. Joe Duff, CEO and co-founder of Operation Migration, as well as one of its three pilots, strutted about like a proud papa once he had landed. He owes it to the animals that taught humans how to fly to protect one of its senior species, he says as an explanation of why he participates year after year. “Hey, the whooping crane [lineage] has been around for 60 million years. If we can do something to save them, then we must.”
HOLLY KORAB is a freelance writer based in Charlottesville, Va. She has written about science and the natural world for a variety of publications for more than 20 years.