Patuxent Wildlife Research Center


Captive Rearing Overview

Most of the Whooping Cranes from Patuxent originated from eggs collected from the wild flock in Wood Buffalo National Park, Canada. Whoopers lay two eggs, but usually only one chick survives. By collecting the second egg, researchers were able to establish the breeding flock at Patuxent while still allowing the wild pair to raise a chick. This helped preserve the valuable genetics of the wild flock without affecting their population. While researchers collected eggs for Patuxent, the number of birds in the wild flock continued to increase. After establishing a captive breeding flock of Whooping Cranes, below is a summary of what each nesting and chick rearing season looks like at Patuxent:

Because the Whoopers at Patuxent lay more than two eggs a year, we need more cranes to incubate some of the extra eggs. This Sandhill Crane at Patuxent helps by incubating a Whooping Crane egg during its critical period. Sandhill Cranes at Patuxent are also used to help ensure the safety of procedures that may eventually be used on Whooping Cranes. They are called "surrogates", or act as substitutes for whoopers.

Sandhill surrogate

Whooper eggs can safely be incubated mechanically in the later stages. Most of these eggs are raised by technicians. The eggs will be examined, candled, and weighed to see how their development is progressing. Eggs lose weight during incubation as the chicks grow and use up yolk and fluid. When an egg loses weight too quickly, we often slow water loss by  placing it in an incubator with high humidity.  Eggs that are scheduled to be raised by Whooping Crane pairs (parent-reared) are left under whoopers to hatch.


From the moment that a whooper chick can see outside of its egg, it will be handled only by a person wearing a crane costume to prevent the chick from imprinting on humans. A technician is wearing a poncho-like body costume and a hood which covers her face. The camouflage netting on the hood allows her to see, but disguises her face from the chick. The puppet head she's holding will be the "parent" to the chick.

A technician examines this just-hatched whooper chick. The technician will make sure his umbilicus is closed, that his yolk sac is completely absorbed, and will spray his umbilicus with an iodine spray to prevent bacterial contamination. Next, the technician will weigh him, put a leg band on him to identify him, and then put him back in the hatcher to dry off. All he wants to do is sleep after all the hard work of hatching.


This 12 day old whooper has a coat of fluffy cinnamon-colored down, bright blue eyes, and a good appetite. He’s learned to eat crumbles from a bowl. His "mother" and "father" are a stuffed model and a puppet head in his pen, but he has a live whooper adult as a neighbor next door. Watching that adult will help him learn how to be a whooper himself. Everything the chick is exposed to--the stuffed model, the puppet, and the live adult--helps in proper imprinting.

12 day old chick

Technicians then take the young chicks out for a walk. They've been following in the grass for good exercise for growing legs and feet. During the walk, technicians purr or play brood calls to the chicks like their parents would, and use the puppet head to show them the mealworms and encourage them to eat.

This whooper chick is around 25 days old. It's amazing how rapidly they grow from that small 6-day-old chick shown earlier.  Regular exercise and a good diet have ensured this chick's rapid growth and good health.

Walking chicks

This whooper chick is around 25 days old. It's amazing how rapidly they grow from that small 6-day-old chick shown earlier.  Regular exercise and a good diet have ensured this chick's rapid growth and good health. 

In another 20 days the change is even more dramatic. These chicks are around 45 days old. They are beginning to grow real feathers, including primary feathers, but the chick down is still there at the tips of the new feathers making them very fluffy. They’ll preen the down away as they new feathers grow until they are sleek all over. 

20 day old chicks

At 65 days of age, the chick is almost fully grown. He's starting to fly, and all his down is gone. His feathers are a combination of cinnamon and white, except for the black wing tips he already has. The color combination helps to camouflage him in the wild. His eyes have changed from blue to gold, though there is still a hint of green in them. As he gets older, the cinnamon feathers will shed, one-by-one, and be replaced with white ones until, after a year, he'll be completely white.

65 day old chick

After a year, the chick will be completely white with black wing-tips like this whooper. His eyes are gold, and the red crown on the top of his head is covered with spare black feathers.

1 year old chick

Captive Rearing Timeline

Day 1

The chick hatches!

Day 2

The chick is an unsteady walker and learns to eat and drink from a red-tipped puppet bill. Technicians work with the chick every hour, dipping the puppet bill into a bowl of water, wetting it, and then dipping the bill into the crumbled food, which sticks to the bill. The chick will peck the food off the bill and eventually follow the bill to the food and water, learning how to eat and drink on its own.

Day 3-4

The chick continues to gain weight and it weighed daily.

Day ≈5

The chick ventures outside for the first time.

Day ≈7-25

The chicks are prescribed walks and swimming sessions with the technicians to combat excessive weight gain, strengthen their leg muscles, and straighten their toes. 

Day ≈25

The chick is transferred to the White Series, which is what we call our collection of large, outdoor pens.

Day ≈70

The chicks are moved to an even larger outdoor pen with ponds in the center. This early exposure to ponds is important. The time spent in the ponds helps train them for life in the wild. Learning to roost in deep water overnight protects cranes from being attacked by predators such as bobcats.  <pond video>

Day >70

The chicks live in their ponded pens until it is time to be shipped to either Wisconsin where they will begin their ultra-light migration path to Florida or Louisiana where they will join other non-migratory whooping cranes for their first winter. 

802 gets drinking lesson

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Webmaster