Journey North Whooping Crane Spring 2006

Discussion of Challenge Question #7:
Faster Flying Free?

Last week, pilot Joe Duff joked about this: It took ultralight pilots 61 days to lead the cranes to Florida last fall, but it took a group of 14 a mere 8 days to migrate home together! So we asked.

"Why can the Eastern cranes make the journey north so much faster than their very first journey south?"

What Students Say
Thanks to all the middle school age students who gave us a lot to think about! You mentioned factors such as bad fall weather, the "newness" of migration on the journey south, the birds' growing strength and eagerness to get to their breeding grounds, and the fact that the plane is simply slower than the whoopers. Marcus also noted, "Maybe there are more thermals available to them on their spring migration than on the fall one." Let's hear more from Joe Duff about these last two ideas. Read on! (You can see all student responses below.)

Pilot Joe Duff Explains the Short Southbound Flights
Normally cranes migrate during midday when the sun's heat is the strongest and creates thermals (rising columns of air). They soar on these "elevators" like hawks or eagles, seldom flapping their wings. Under good conditions they can stay aloft for hours and cover hundreds of miles at a time with little effort.
(Photo: Operation Migration)

We are not able to fly the way they do and our aircraft, although state of the art, perform at a fraction of their ability. Instead, our birds learn to use the wing of the aircraft and the "vortices" or wake it creates to surf through the sky and ease their workload. This can only happen when the air is smooth and the wing remains stable. If we encounter turbulence and the wing begins to bounce around, the birds must move away and follow from a safe distance. When this happens they are forced to flap-fly and they soon tire. Our flights are therefore limited to the calm air of early morning. That's also when cooler temperatures prevent the birds from overheating. This learned behaviour is temporary. Once on their own, they will instinctively fly like wild birds and use thermals to make their way north.

Student Responses to Challenge Question #7

Marcus (Homeschool in Mount Airy, Maryland, Grade 6.)
There are probably several reasons that contribute to the slower pace of the whoopers' first journey south. Perhaps it takes longer, because they are younger, and not as strong yet, and because migration is new to them. Another possibility is that there are more headwinds when they are going south than when they are headed north, and these often make them have to stop. Also, when they are heading south, they seem to stop at a staging area for several weeks to eat lots of food. They don't use staging areas on their way north, probably because they are already pretty well fed and are anxious to get back to their nesting ground and stake out their territory for the season. Also, maybe there are more thermals available to them on their spring migration than on the fall one.

Emily, TJ, Daniel, and Brittany (Ferrisburgh Central School, Ferrisburg, VT, Grade 5)
The weather and the people were holding the cranes up. When we read the flight reports for last year, it shows that there was very bad weather. There was a lot of wind, rain and some tornados. When the weather is bad, they don't fly at all, but stay on the ground. If it is very windy, the ultralights would be pushed backwards rather than make progress. There were many temperature changes that were happening. The temperature changed rapidly. Also, the ultralight plane can't go as fast as the birds can go. The plane had to stop and get fuel. There were a lot of people that were traveling together and that would also make it go slower.

Pranav, Amrit, Mansimrat, Tripti, Jocelyn, Abhi, Vanessa, Jason, Ana (Iselin Middle School, grade 7)
The first time South for the new Eastern flock was extremely difficult. They had never traveled south before. They had no landmarks to follow and had to be led. Since they are nowfamiliar with the landmarks and obstacles, it should be easier for them to find their way North. The landmarks will guide them and they will have a better understanding of their route. The cranes are also stronger now. Also, the winds pushing the cranes North in the spring are milder then the winds during their journey South which makes flying easier.

Nick, Kathryn (Iselin Middle School, grade 7)
We think the Eastern cranes make their second journey much faster because on the journey South there are more obstacles like weather. The weather is sometimes too poor to travel, like strong winds and major tornados. So, they must stop. But in the spring, there aren't any strong storms and the trip is smoother.