Migration Complete
All of the Whooping cranes have returned north. What do tracking maps show - and how did a late-season storm affect nesting?

Whooping Crane

After returning briefly about 3 weeks ago, siblings 4-17 and 6-17 have traveled hundreds of miles exploring Wisconsin. This behavior is called "spring wandering."
Photo: Operation Migration


May 4, 2018
by Heather Ray, Operation Migration

Migration Complete
All of the Whooping cranes have returned north. A couple ventured into neighboring Michigan and one of those cranes, number 39-17 did find her way back south and around the bottom of Lake Michigan! From there, she flew north through Illinois and back into Wisconsin! Here's the tracking map:

Whooping Crane

Why Such a Long Route?
Whooping cranes use warm, rising columns of air to fly long distances. As the sun heats the surface of the earth, these warm air currents act like elevators, which lift migrating cranes and other soaring birds to great heights. Once the thermal begins to fade out, the cranes simply glide until they find another thermal elevator.

Unfortunately, there are no thermals over large bodies of water such as Lake Michigan, so cranes must go around the lake, instead of simply flying across to the other side.
Here is a map showing the GSM remote tracking unit ‘pings’ showing the route 39-17 took from Michigan to Wisconsin.

It’s interesting that once #39-17 made it back to Wisconsin, she didn’t return to the area at Horicon Marsh where she was released. Instead she continued north to Outagamie County where she seems to have settled.

Spring Wandering
Number 39-17 isn’t the only young Whooping crane logging mega-miles! Siblings 4-17 and 6-17 successfully returning to White River Marsh in Green Lake County about 3 weeks ago. Since then they have been exploring. Take a look at their GSM hits for just a 4 day period in late April. These two have covered a LARGE portion of the eastern half of Wisconsin. This is something we refer to as “spring wandering” and is something young, un-paired Whooping cranes do. After all, with no mate or no breeding territory to defend, there is no need to rush back to a specific location. Travel while you’re young!

Whooping Crane

Late-Season Snow and Nests
An unsually late snowstorm in mid April dropped 12 – 20 inches of wet, heavy snow over central Wisconsin. What this meant for the Whooping cranes is that, sadly, a number of nests failed.

From 3-5 first nests at Necedah NWR were abandoned likely due to a snowstorm and a freezing of the marshes. Pairs 9-03/3- 04, W1-06/1- 10, 13-03/9- 05, and likely also 36-09/18-03, 16-07/1- 04 were incubating on 13 April prior to a snow storm, and as of 27 April were no longer incubating.

It is still early in the season though, so we’re hopeful there will be some re-nests very soon. In the next update, I hope we’ll be able to tell you about some re-nesting attempts!

Over and out…

Heather Ray
Operation Migration