Whooping Cranes
The whooping crane (Grus americana) is named for the “whooping” sound that it makes. It is the tallest bird of North America and is only one of two crane species native to North America, the other being the sandhill crane (Antigone canadensis). It is estimated the lifespan of a whooping crane is between 22 and 24 years in the wild.
Our journey to see the endangered whooping crane began with our arrival into Corpus Christi from Sacramento, California. We had chartered a boat and crew that specializes in observing the cranes as well as other wildlife in the area around Rockport, Fulton and Aransas National Wildlife Refuge (see map above). 
A mature adult whooping crane is white with a red crown and a long, dark, pointed bill. However, immature whooping cranes are cinnamon brown. While in flight, their long necks are kept straight, and their long dark legs trail behind. Adult whooping cranes’ black wing tips are visible during flight. 
Their calls are loud and can carry several kilometers. The birds will make “guard calls” which are thought to warn their partner or offspring of imminent danger. The whooping crane couple will jointly unison call, usually just after waking, after courtship or when defending their territory. The first unison call ever recorded in the wild was taken in the whooping cranes’ wintering area of the Aransas National Wildlife Refuge during December 1999.
Listen to Ryan Jackson Logan’s recording of an immature whooping crane as it was feeding with its parents:
Above, boat tours in the water off the Aransas National Wildlife Refuge, offer close-up, unobtrusive views of whooping cranes.
It is believed that whooping cranes have never been naturally common in North America. However, in the 1800s and 1900s the species suffered major declines in population due to the destruction of their habitat and overhunting. Yes, people eat these magnificent birds! Despite a ban on hunting, there is still a great deal of illegal hunting that continues, and enforcement is difficult.
By 1870, the population of whooping cranes went down to under 1,400. Prior to the settling in North America by Europeans, it is estimated that the whooping crane population was over 10,000 birds.
Conservation efforts, not just in America but worldwide, was limited and woefully inadequate before 1940 because of the effects of the Great Depression. By 1938 the whooping crane population had shrunk to a single migratory flock of 15 adults and 13 birds living in a non-migratory population in Louisiana. Unfortunately, half of these non-migratory birds were killed during a hurricane in 1940 and the balance never reproduced.
By 1940, due to unrestricted hunting policies, the same that wiped out the passenger pigeon, and the destruction of much wildlife habitat, the population of whooping cranes was down to 21 wild specimens and 2 captive birds. It was beyond time for the federal government to lead conservation efforts.
In 1950, when John J. Audubon’s portfolio of his bird drawings was published in a book club edition, the editors noted that only about 30 birds survived in the wild. At that time no one even knew where these magnificent birds bred or where they spent their summers.
It is estimated that the range of the whooping crane had at one time spread through much of the American Midwest all the way to Mexico. Finally, in 1954, researchers were able to identify that the summer breeding grounds were in Canada’s Wood Buffalo National park. This muskeg ecosystem has become the last remnant of their breeding grounds.
Research efforts began in earnest, and it was observed that typically whooping cranes produce two eggs, however, they raise only a single chick. Knowing that the second chick would not survive, researchers began to harvest the second egg and introduced it to a captive breeding program at the Patuxent Wildlife Research Center in Maryland. It was proven to be a successful program that used the more numerous sandhill cranes as surrogate parents, and it also showed that the removal of the second whooping crane egg had no affect on the reproductive success of wild whooping cranes.
Since its establishment in 1936 as the first wildlife experiment station in the United States, the Patuxent Wildlife Research Center has been a leading international research institute for wildlife and applied environmental research for transmitting research findings to those responsible for managing the United States’ natural resources, and for providing technical assistance in implementing research findings to improve natural resource management.
Whooping cranes nest on the ground, usually on a raised area in a marsh. The female typically lays 2 eggs, usually in late-April to mid-May. The blotchy, olive-colored eggs average 2½ inches in width and 4 inches in length (60 by 100 mm) and weigh about 6.7 ounces (190 g). The incubation period is 29–31 days. Both parents brood the young, although the female is more likely to directly tend to the young. Usually no more than one young bird survives in a season. The parents often feed the young for 6–8 months after birth and the ending of the offspring-parent relationship occurs after about 1 year.
Whooping cranes make the 2,500-mile journey from their Canadian breeding grounds in northern Alberta’s Wood Buffalo National Park to the coastal marshes of Texas each year. The migration south to Texas can take up to 50 days.
During their migration, whooping cranes seek out wetlands and agricultural fields where they can roost and feed. The Salt Plains National Wildlife Refuge in Oklahoma is a major migratory stopover for the crane population hosting over 75% of the species annually. The birds often pass large urban centers like Dallas-Fort Worth, Waco and Austin. Though whooping cranes rarely stay in one place for more than a day during migration, it is important that they not be disturbed or harassed at these stopovers. As a federally protected species, it is illegal to disturb or harass these birds.
Whooping Cranes were charter members of the Endangered Species Act when it was signed in 1973, however, by 1976, the wild population numbered only 60 birds and had increased at an average of only one bird per year over the past decades. Through dedicated efforts by numerous volunteers and private entities like the National Crane Foundation, the wild crane population began a steady increase, such that in 2007 the Canadian Wildlife Service counted 266 birds at Wood Buffalo National Park, with 73 mating pairs that produced 80 chicks, 39 of which completed the fall migration, while a United States Fish and Wildlife Service count in early 2017 estimated that 505 whooping cranes, including 49 juveniles, had arrived at Aransas National Wildlife Refuge that season. As of 2020, there were an estimated 677 birds living in the wild, in the remnant original migratory population as well as three reintroduced populations, while 177 birds were at the time held in captivity at 17 institutions in Canada and the United States, putting the total current population at over 800.
With the recent Whooping Crane Eastern Partnership Reintroduction Project, whooping cranes nested naturally for the first time in 100 years in the Necedah National Wildlife Refuge in central Wisconsin, United States, and these have subsequently expanded their summer range in Wisconsin and surrounding states, while reintroduced experimental non-migratory populations have nested in Florida and Louisiana.
Breeding populations winter along the Gulf coast of Texas, United States, near Rockport on the Aransas National Wildlife Refuge and along Sunset Lake in Portland, Matagorda Island, Isla San Jose, and portions of the Lamar Peninsula and Welder Point, which is on the east side of San Antonio Bay. Several whooping crane watching boat tours can be found in the area and it is advised that reservations be made well in advance.
Whooping cranes forage while walking in shallow water, marshes or in fields while probing with their long, pointed bills. They are omnivorous but tend to be more inclined to a carnivorous diet.
In their Texas wintering grounds, this species feeds on various crustaceans, mollusks, fish (such as eel), small reptiles and aquatic plants. Potential foods of breeding birds in summer include frogs, small rodents, small birds, fish, aquatic insects, crayfish, clams, snails, aquatic tubers, and berries. Six studies from 1946 to 2005 have reported that blue crabs are a significant food source for whooping cranes wintering at Aransas National Wildlife Refuge, constituting up to 90 percent of their energy intake.
Waste grain, including wheat, barley, and corn, is an important food for migrating whooping cranes, but whooping cranes don’t swallow gizzard stones and therefore digest grains less efficiently than sandhill cranes. (A gastrolith, also called a stomach stone or gizzard stone, is a rock held inside the gastrointestinal tract of some species and are used to grind food in animals that lack grinding teeth.)
The whooping crane has many predators, aside from human beings, that include the American black bear, wolverine, gray wolf, cougar, red fox, Canada lynx, bald eagle, and common raven. Golden eagles have killed some young whooping cranes and fledglings. Regardless, it is known that American alligators have taken a few whooping cranes in Florida, and that bobcats have killed many captive-raised whooping cranes in Florida and Texas. In Florida, bobcats have caused the great majority of deaths among whooping cranes, including several ambushed adults and the first chick documented to be born in the wild in 60 years.
Due to the cranes large size, adult birds in the wild can fend off most predators or avoid attacks by medium-sized predators such as coyotes when aware of a predator’s presence. However, captive-raised cranes that have not learned to roost in deep water makes them vulnerable to predator ambush. Since they do not have the experience juvenile cranes are typically vulnerable to ambushes, mainly by stealthy bobcats. Patuxent Wildlife Research Center scientists believe that this is due to an overpopulation of bobcats caused by the absence or decrease in larger predators (the endangered Florida panther and the exterminated red wolf) that formerly preyed on bobcats. At least 12 bobcats have been trapped and relocated in an attempt to save the whooping cranes.
Despite the efforts to increase the whooping crane population, a major hurdle with some of these reintroduced bird populations has been deaths to due illegal hunting. Over a period of two years, five of the approximately 100 whooping cranes in the Eastern Migratory Population were illegally shot and killed. One of the dead cranes was the female known as “First Mom”. In 2006, she and her mate were the first eastern captive raised and released pair to successfully raise a chick to adulthood in the wild. This was a particular blow to that population because whooping cranes do not yet have an established successful breeding situation in the East.
When sandhill crane and waterfowl hunting seasons open and whooping crane migration is in full swing, the Texas Parks & Wildlife Department (TPWD) urges hunters to be extra vigilant. Whooping cranes are sometimes found in mixed flocks with sandhill cranes, which are similar in flight but gray and slightly smaller. With their all-white body plumage and black wingtips, whooping cranes may also resemble snow geese, which are much smaller and have faster wing beats. A video detailing the differences between snow geese and whooping cranes can be found on the TPWD YouTube Channel.
In case you need help identifying a snow goose, a sandhill crane, or a whooping crane:
The above is a snow goose.
The above are sandhill cranes.
The above is a whooping crane.
In 1994 the endangered North American whooping crane and Chinese black-necked crane were featured on postage stamps that were jointly issued by China and the USA, in hopes that they would advance wildlife conservation and friendship between the two countries. Artists at the Clarence Lee Design Studio in Honolulu developed several different concept designs and Chinese nature artist Zhan Gengxi created the final artwork, influenced by one of the concept designs:
If you enjoy nature and birding in particular, a trip to see the magnificent whooping crane may just be a trip of a lifetime. To see them in the wild is amazing and will certainly add another drop in the bucket!
All photographs are the copyright of Jim Jackson Photography. Please contact me with any questions, comments, or for authorization to use photos or for signed, high-resolution prints.
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Please see https://savingcranes.org for more information.
