Breeding Studies
Our team is conducting studies to determine breeding success among Sandhill cranes. The results should indicate how their cousins – the Whooping cranes will fare.

Whooping Crane

"Checking in on the chicks..."

May 23, 2018

by Heather Ray, Operation Migration

Breeding Study at White River Marsh

Our team is currently conducting a study in the White River Marsh area of Wisconsin to determine breeding success among Sandhill cranes. The results should indicate how their endangered cousins – the Whooping cranes we have been working to safeguard – will fare in that area.

Breeding Study at Necedah National Wildlife Refuge
The same study is taking place at Necedah National Wildlife Refuge and is in its second year. The first year results, although preliminary, seem to indicate Sandhill cranes are having just as much difficulty as Whooping cranes raising offspring to the critical age when they can fly and escape predators.

Searching for Nests
The way it works, is we first search for Sandhill crane nests so that we know where chicks will be once the eggs hatch. This may sound simple enough until you learn the way to locate a nest is to walk into the marsh where nests may be located.

Sandhill cranes (and Whooping cranes) construct nest mounds using cattails and grasses. Both of these can grow to be very tall and walking through water and mud up to your knees (or higher) can be tiresome.

So far, we have located 12 nests and have tagged 2 small chicks! Here is one of the nests we located.

Whooping Crane
This nest is officially known as JD07N.
J. Duff

Bowl-shaped Nest
See how the nest has a bit of a bowl shape in the center? This is from the adults incubating the eggs but it also means the eggs won’t roll out of the nest. Each nest is made so that it sits higher than the water level surrounding it. If it rains a lot, adults will often begin pulling additional vegetation onto the mound to make it higher and prevent flooding.

Surrounded by Water
The water surrounding the nest acts as an “alarm system” for the incubating cranes. Any predators, or people who approach make noise splashing through the water and the adults take flight. This is how we know there is a nest nearby and we try to find it quickly so the adults can return to their incubation duties.

Checking Regularly
We check known nests 2 or 3 times each week until eventually, we see the adults in a nearby field foraging with their tiny chick(s).

We captured this fluffball late last week.

Whooping Crane

This feisty 3-week-old Sandhill Crane chick appears to want to eat Jeff.
Heather Ray

Planning Approach
Jeff, Brooke, Joe and I planned our approach: Brooke and I walked into the field from the south, while Jeff and Joe approached from the road. There was a marsh near the road and we didn't want the parents to lead the chick into the marsh when they spotted us.

Scooping Up a Chick
As we drew near, the two adults flew off and we began searching for the chick in the vegetation. After about 20 minutes, Brooke spotted it and scooped it up.

Weighing In
First order of business is to place it in a clean pillowcase to get a weight on it. This little critter weighed in at 665 grams. By comparison, the first chick we captured and radio-marked was 110 grams - waaaay smaller.

Adhering a Transmitter
Next Brooke held the chick while Jeff and Joe prepared and placed the 2.2 gram transmitter on the chicks' back. It will be held in place by eyelash glue until it eventually falls off. The battery life on these tiny transmitters is 115 days - plenty of time to learn if it survives to fledge.

Whooping Crane

The fabric patch containing the tiny transmitter has been colored
to be the same color as the chick.
Heather Ray

Measuring to Estimate Age
Once the transmitter is in place, we measured the tarsus, which, along with the mass, will give us a good idea of the age of this chick. This guy had a tarsus measurement of 11 centimeters, making him/her approximately 3 weeks of age. This also means its parents continued to incubate during the mid-April storm. Impressive!

Ready for Release
In total, we had this little fluffball in hand for less than 6 minutes. Once he was ready to be released, Brooke carried him about 15 feet away and placed him on the ground.

Whooping Crane

It didn't take long before he ran away from the four of us scary humans. 


We're happy to report both mom and dad returned to join him after approximately 15 minutes! Check out our Daily Field Journal to see a video clip that captured the moment the chick was released.

Over and out…

Heather Ray
Operation Migration