Cool Facts About Whooping Cranes

(Photo by Barbara Niccolai, USGS Patuxent Wildlife Research Center)

At Patuxent, we identify each egg with numbers.
An average Whooping Crane (WC) egg is 102 mm long (4 inches), and weighs 208 grams (7 ounces).
Both parents take turns incubating the egg. They do this by using their bodies to keep the egg warm, and by turning it so the chick grows properly.
WC eggs are incubated, on average, for 30 days.
Egg color varies from a soft blue to a grey-green or tan, usually with tan and brown splotches.
In the wild, both parents feed and raise the chick.
The splotchy color of the egg provides natural camouflage against the russet colors of the nest. This helps keep it safe from predators.
In the wild, whoopers normally lay 2 eggs but usually only one chick survives.
At Patuxent, whoopers lay more than 2 eggs, enabling us to produce more chicks for release.
Whoopers are born with blue eyes that change color as they grow older. At about 3 months, their eyes will be a stunning aquamarine color. At about 6 months, their eyes will be bright gold.
Whooper chicks have down, not feathers, when they hatch.
Their color varies from a light blond to a dark cinnamon-brown.
Our chick's parents are two whoopers the staff calls Spike (the male) and Shelly (the female). Spike and Shelly are one of our best pairs. Their first breeding season was in 1992, and they've given us many chicks since then. Their chicks usually are very healthy without any genetic problems. While Spike and Shelly won't be keeping this chick to raise, they will get to raise one of their own chicks later in the season. They are excellent parents. This chick is from their fifth egg.
Whooper parents catch food for their chicks all day long. At Patuxent, the chicks' human parents have it a little easier. We feed the chicks a prepared diet called Crane Chick Starter Crumbles. It's a green-gray pelleted food that looks a little like rabbit food, that's crushed into a crumbled form. The diet is a balanced formula, with everything in it the chick needs to grow.   This chick, about 4 days old, follows the red-tipped puppet bill as it probes around the food. Technicians work with the chicks every hour, using the puppet head to teach the chick what to do. The technician dips the puppet's bill into a bowl of water, wetting it, then dips it into the crumbles which stick to the bill. The chick will peck the food off the bill, and eventually follow the bill to the food or water, and learn to eat or drink.
Even in the wild, whooper parents have to teach their chicks to eat and drink. They teach them to eat by catching food for them--insects, small fish and invertebrates, and small mammals like mice or voles. Videos taken of crane parents on the nest have shown them teaching their chicks to drink by patiently dipping their own beaks into water and letting it drip from their bill. Most birds are attracted to moving water, so the water dripping from the parent's bill is very attractive to the chick who will try to catch it and end up getting their first drink by accident. We use the puppet head in a similar way, splashing it in water until the chick tries to grab the red tip or the falling drops. We have to be just as patient as crane parents who spend hours teaching their chicks this first lesson of survival.
How do we know our chick is a "he"? Well, actually, we don't. There isn't any way to tell the sex of a whooper chick without a blood test. Since each chick is a distinct individual, with his or her own personality and temperament, the staff often dubs each one as "he" or "she" in a random way. We know we have a 50% chance of being right! We don't name all the chicks, but when we do, we try to pick names that could be given to either sex, such as "Patuxent," "Chesapeake," and "Laurel." The chicks will have a blood test to determine their sex when they're older. We enjoy checking the results with our guesses.
At around 40 days of age our chick will grow feathers that are cinnamon and white in color, and he'll have black wing tips.
After a year of age, he will be pure white with black wing tips and black facial markings. The top of his head will be covered with bright red skin with spare black feathers. This is called a "crown."
Tracking a chick's weight tells us a lot. Medication dosages are given by weight. Whoopers grow so rapidly that the evening dose will be different from the morning. Birds on treatments get weighed twice a day. Chick weights are often the first thing affected when a chick becomes ill, and can signal a problem before there are other symptoms. If chicks gain weight too fast, they can develop leg problems. Tracking weights allows us to make adjustments to the diet and exercise program to prevent such problems.
Exercise: Walking. Everyone needs regular exercise to be healthy. Crane chicks are no different. In the wild, chicks walk with their parents in search for food. They cover a lot of ground while foraging, and the steady walking helps the chicks grow those long, straight legs. Chicks being hand-reared don't need to search for food, and even though they have outside pens to wander around in, they can be lazy. To make sure the chicks grow up healthy, the staff takes the chicks out for walks to provide this critical exercise.
Exercise: Swimming. In addition to walking, another good exercise for hand-reared whooper chicks is swimming. Swimming is a natural activity they do with their parents in the wild, since the young chicks are usually too small to walk through the deep water their parents can wade through. If crane chicks gain too much weight too fast, they can have problems with their legs. Swimming is especially good for chicks who may have an injured leg, or when it's too hot to take them for walks.
We don't know how many whooping crane chicks get sick in the wild. But some chicks in the crane chick building do get sick or sometimes they get injured. We are often able to treat these chicks, and many recover. Crane chicks seem especially prone to respiratory problems. Treatments are extensive and recovery can take a long time. Injuries also can be treated, but leg injuries with chicks whose legs grow so long can be fatal. Fortunately, Patuxent's veterinarian, Dr. Olsen, is a world-expert on cranes, so we know our chicks are getting the best care.
Conditioning For Release-- Pond Experience--. To keep the crane chicks in a clean, sanitary environment, their outside runs are dry sod, good for feet and legs. However, in nature, they would spend a lot of time in marshes and ponds. Crane chicks need to see these natural environments and learn what they're about, or, when they're released into the wild, they won't know what to do. So after crane chicks are exercised by walking or swimming, they're taken to a small human-made marsh. A costumed technician with a puppet can introduce the young chick to this natural environment and help him discover it much the way his parents would.   
Because we only want whoopers imprinted on their own species, less than 10 chicks each year are parent-reared. As our young whoopers mature and begin to lay eggs, more chicks can be parent-reared. But because we stimulate the whoopers to lay more eggs than they would in the wild, we will always need to costume-rear most of the chicks. However, letting the whoopers raise a chick of their own has many benefits. It helps strengthen the pair-bond (or the breeding relationship) between the adults. The parent-reared chick is wilder than costume-reared chicks, so later, when grouped with these tame  chicks, this wilder chick will help them become more wary. We can never duplicate all the things crane parents teach their chick. Parent-reared chicks might be able to teach costume-reared chick different behavior patterns.
At Patuxent, non-endangered sandhill cranes act as substitutes for the whooper, to enable us to do studies that might be too dangerous to risk with rare whooping cranes. New medications, medical techniques, or food items are tried first on sandhills. Sandhills also act as surrogate incubators for the extra whooping crane eggs we produce. However, they do not raise whooping crane chicks, even though many of them are excellent parents. This would cause the whoopers to become imprinted on sandhills, and would try to mate with sandhills when they matured. Sandhills have been critical in our migration studies, and we have learned a great deal from them. Sandhills were also essential in release studies done in Florida years before the first whoopers were sent there.
 When Tux is around nine months old, sometime in January or February of 2001, he'll be put on a jet to Florida. There, he'll be given a special leg band with a radio on it, and penned for a month with other birds his own age--the chicks we're raising now. His wing will be tied so he can't fly out of the pen. He'll spend that time, with the rest of his group--his cohort--getting used to the surrounding area which will be new to him. After a month, his wing will be freed. It'll take about a week before the stiffness in that wing will ease, then he and his cohort will fly out of the pen on their own. They may join with other whoopers already in the release area, or his cohort may stay together and discover their new world by themselves. They'll be tracked every day by radio. We can only hope that Tux will grow up healthy and survive in Florida to someday be another member of a successful pair of crane parents. He and the other chicks we are currently raising are all part of the effort to save the whooping crane.
 The most vulnerable part of a growing crane chick is his legs. A crane can live in captivity with an injured wing, but if something goes wrong with his rapidly-growing legs, it can quickly become life-threatening. Some leg problems seem to be genetic. Others can be improved or eliminated with proper exercise and nutrition. Toe-problems and wing problems like angel wing seem to be related to exercise and nutrition, though there may be a genetic component, too. We're still learning how to manage these problems that seem to be a result of a captive environment. At Patuxent, chicks parent-reared by cranes have less of these problems than hand-reared birds.
  Whooping Crane pairs at Patuxent lay from 2 to 6 eggs each year, but they will only raise one chick. So technicians will raise the others. 
Most experienced whooper parents don't mind if the chick they raise isn't their own. Inexperienced parents are given sandhill crane chicks to raise for "practice." 
Parenting skills in whoopers, like in humans, is learned. Whoopers become better parents with experience.
Patuxent has sent captive-reared whooper chicks to be released in Florida since 1993. Patuxent is also working on studies that will determine if another flock of whoopers can be established in Wisconsin. This flock will be migratory.
There are currently over 80 birds in the Florida flock. Many of them are from Patuxent, but chicks have also been sent from other institutions: The International Crane Foundation, the Calgary Zoo, and the San Antonio Zoo.
Whoopers in Florida have been showing nesting activity since 1997. However, this is the first year that a pair has successfully hatched and reared chicks. Low water levels in central Florida have had a negative impact on the birds' ability to nest successfully.
At Patuxent, whooping crane chicks are raised in dry pens for sanitation and health reasons. However, young cranes have to learn to be wading birds. So, when chicks are young, costumed caretakers take them out to a small, human-made pond to learn to forage and wade.  
  This early "pond exposure" helps the chicks quickly adjust to the large pond pen they will live in after 70 days of age. Fledged birds who have never had any pond exposure might find the pond too strange of an environment and might spend less time in the water. The early exposure makes the pond a familiar environment. 
Even though the pond pens at Patuxent are protected against predators, it's important for the birds to learn to roost in deep water (over 8 inches) at night. When the birds are sent to Florida, roosting in water at night will help keep them safe from their most prevalent predator, the bobcat. 
All our whooper chicks have fledged! They're all older than 70 days, and are capable of flying, so they've graduated from the crane chick rearing facility, and are now living in the pond pens in the White Series. The chicks which have been parent-reared by crane pairs have been separated from their parents and are also living in the pond pens.
The time the chicks will spend in the ponds helps to train them for life in the wild. The chicks will learn to live in "cohorts" -- small groups of similarly-aged birds. In the wild, there is safety in numbers, so having friends to move around with is good for young cranes. There are 28 crane chicks scheduled for release in Florida.
We now know the sex of our chicks. By analyzing blood samples, we know which of our birds is male or female. Tux is definitely a male, but so is his "sister" Chessie. We need to know the sex of the birds so that, when releasing chicks in Florida, we don't skew the sex ratio too severely one way or the other. We want to make sure the birds have an adequate number of potential mates to chose from.
Mississippi chicks and whooper chicks look similar. But to people who work with them, the differences are obvious. Mississippi chicks are 20-50 grams lighter, hatching at 100 grams as opposed to the whoopers' 140 grams. The Mississippi chick is lighter in color than the whooper, with pink legs. Their eyes seem larger, and their bills smaller. The whooper is usually dark with dense down and dark legs. Since they come from different environments, this makes sense: the whoopers need thick down to survive in their northern breeding range, while the Mississippis' native home along the Gulf coast is much warmer.
Before any research can be done on whooping cranes, it is first tried on non-endangered sandhill cranes such as Florida sandhill cranes or Greater sandhill cranes. Once the research seems safe with a good chance at success, only then is it done on whoopers.   
When Mississippi sandhills were at Patuxent, these rare birds were given the same concerned care. Breeding and release programs were tried out on Florida and Greater sandhills before begun on the Mississippis. Success with these programs was a promising prediction for similar work with whoopers.   
Releasing animals into the wild from a captive population can be risky. Captive animals can carry organisms which might be dangerous to wild animals that have never been exposed to them. The quarantine procedures at Patuxent are an attempt to prevent the transmission of illnesses between our captive flock and Florida's wild cranes. 
Some of the tests taken to ensure the health of the release whoopers are: physical exams including weights, fecal tests and treatment for parasites, blood chemistry, virus serology (to check for antibodies to certain crane viruses), tests for salmonella, coccidia, avian tuberculosis, and high zinc or lead levels from metal ingestion. Blood is also kept for future research.
When cranes swallow metal, it might pass harmlessly through their digestive system. However, some sharp pieces can puncture vital organs. Even metal that doesn't cause injuries can stay in the digestive system long enough to cause high levels of zinc or lead in the blood. These toxic metals can impact the bird's ability to survive in the wild. That's why it's important to test the blood for these metals and to x-ray the birds to make sure they are metal-free.
Whoopers are born with blue eyes. Their eyes gradually change color until they are a bright gold. At 7 months, Tux's eyes are a clear yellow, having lost all hints of blue. The yellow color will grow darker as he matures.
Whoopers lose their cinnamon-colored feathers over time. They lose the colored feathers in distinctive patterns. Each time a cinnamon feather is lost, a white feather grows in its place. Eventually, there are almost no cinnamon feathers, only white ones. The feathers on the head and neck are the last to change, and some can still be seen as the bird nears 1 year of age.
As the whooper loses the last of these cinnamon feathers around the head, the feathers on the very top of the head, which Tux still has, will fall out. In its place will be a patch of rough skin that will, at first, be a dull plum color. As the feathers continue to fall out, spare black, hair-like feathers will replace them, and the rough skin will grow bright red. Eventually, it will be the whooper's crown, a patch of skin that changes with the bird's moods. The crown helps the crane communicate his feelings to other cranes. His bill, too, will become much darker. 
Currently, there are 86 whooping cranes living wild in central Florida. The release effort has been hampered by the drought in Florida that is now in its third year. Low water levels threaten the birds' survival by reducing habitat, food choices, and roosting sites. Cranes roost in water at night to protect themselves from predators. This drought is the longest Florida has experienced in 100 years.
Another serious problem for the Florida whoopers is the over-population of bobcats. This predator no longer has predators who prey on it, so its numbers have escalated. The endangered Florida Panther and native wolves both preyed on bobcats, but are no longer a viable part of the Florida ecosystem, so the bobcat population is unchecked. The great majority of whooping crane mortalities in Florida have been to bobcats. There have only been a few mortalities caused by alligators. A few mortalities have also been caused by car and truck collisions.
We try to release enough birds from every family to ensure good genetic diversity. However, some of the families are better at surviving than others. We're trying to determine why that is, but it will take more research before we have the answers.
There is only one remaining wild flock of whooping cranes. This flock, numbering more than 150 birds, migrates annually from Wood Buffalo National Park in northern Canada to the Aransas National Wildlife Refuge on the Texas Gulf Goast. This arduous journey is almost 2700 miles and takes several weeks. They migrate this path with their young-of-the-year chicks, who are usually around 5 months old when the migration begins. It was this flock which once dwindled down to less than 20 birds around the 1950's. Active intercession on the part of the United States government, the Canadian government, and numerous conservation groups helped pull this flock from the brink of extinction.
Recovery plans call for establishing a non-migratory flock of whoopers, which has begun in Florida, and a second migratory flock. WCRET has researched migration dynamics since the 70's. In 1997, WCRET, in partnership with Kent Klegg, proved that human-reared whooper chicks would follow an ultra-light aircraft and migrate back along a route established by humans. From 1997-2000, WCRET, in partnership with Operation Migration, proved that costume-reared sandhill cranes would follow an ultra-light and migrate along a route established by humans. In 2001, as members of the Whooping Crane Eastern Partnership, we hope to rear and train whoopers who will be used to establish this second migratory flock.
Other research projects include: efforts to improve whooping crane propagation, ways to better understand the whooper's genetic structure, techniques useful in monitoring and surveying populations in the wild, gene pool preservation, cryopreservation, behavioral studies useful in improving captive propagation and the survival of birds released to the wild, veterinary studies to improve the quality of birds released tot he wild and the general health of captive and wild populations.
Our first whooper chick hatched on April 9th. It was one of Spike and Shelly's chicks. That chick is being raised for the Florida release program, and so far he's a healthy, active chick. We currently have 5 whooper chicks on the ground, two of them hatched on Easter day. So far, we have 32 whooper eggs from our breeding flock. It takes a while to determine how many of the eggs are fertile, but they each hold the promise of another whooper to bolster the numbers of this rare species.
We currently have 9 producing female whoopers. This is one more than last year, since a new whooper female, Annie, laid her first egg this year.
Not all the chicks will be raised for the Florida release program. This year we plan to raise some of the chicks for a new migratory release program. Those chicks will be trained to fly behind an ultralight aircraft, and to migrate from Central Wisconsin to Florida. Along with our partners, Operation Migration, we have successfully done this with non-endangered greater sandhill cranes. We hope that this year will be the beginning of the establishment a new, migratory whooper flock.
Our first whooper chick is now over 30 days old. We currently have 18 healthy whooper chicks on the ground. More are on the way.
We've been fortunate to have 2 new females produce eggs this year. It's always exciting to have new pairs come into production.
12 of our current crop of chicks are slated for the Florida release program, and 6 are being raised for the new migratory release program.