One of the most inspirational bird migration stories that I’ve heard of is that of the Whooping Crane (Grus americana), which is severely endangered. As a species, they were reduced to 15 individuals by 1941, due to habitat loss, prompting the initiation of a captive breeding program. Today their population is nearing 500 birds, of which over 350 are surviving in the wild.
Their breeding habitat is the muskeg of the taiga; the only known remaining nesting location is Wood Buffalo National Park in Canada and the surrounding area. 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 terminus of the offspring-parent relationship occurs after about 1 year. Their winters are spent in Texas in the Arkansas National Wildlife Refuge.
Attempts have been made to establish other breeding populations in the wild. One project by the United States Fish and Wildlife Service and the Canadian Wildlife Service was initiated in 1975 involved cross-fostering with Sandhill Cranes to establish a second self-sustaining flock. Although 85 chicks from the 289 Whooping Crane eggs transplanted into Sandhill Crane nests learned to migrate, the Whooping Cranes failed to mate and reproduce; the project was discontinued in 1989. A second involved the establishment of a non-migratory population near Kissimmee, Florida by a cooperative effort led by the U.S. and Canadian Whooping Crane Recovery Team in 1993.
The third attempt is what is depicted in the tall image to the right, and is really quite fascinating. It involves the reintroduction of the Whooping Crane to a new flyway established east of the Mississippi river. This project uses isolation rearing of young Whooping Cranes and trains them to follow ultralight aircraft, a method of re-establishing migration routes pioneered by Bill Lishman when he led Canada Geese in migration from Ontario, Canada, to Virginia and South Carolina in 1993. The cranes are costume reared from hatching, taught to follow an ultralight aircraft, fledged over their future breeding territory in Wisconsin, and led by ultralight on their first migration from Wisconsin to Florida; the birds learn the migratory route and then return, on their own, the following spring.
Other fun facts:
- They are the tallest birds in North America. Males are almost 5 feet (1.5 m) high, with a wingspan of about 7.5 feet (2.4 m). Females are slightly smaller–yet these huge birds weigh only 11-16 pounds. They can also live to 50 years old!
- Whooping cranes take their name from their distinctive whooping call. During the early spring courtship, a pair of birds may perform a duet, or unison call. A nesting whooper frequently bugles loud and clear during the early morning hours. This sound carries over several kilometers, and it is used by the adults to advertise their breeding territory to other Whooping Cranes. Adult birds at the nest use a purring sound referred to as a contact call to communicate with newly hatched chicks.
- They eat mostly crabs, crayfish, frogs and other small aquatic life. They rarely eat fish. On the wintering grounds, blue crabs are the whoopers’ favorite food item. Blue crabs in their diet are important in helping cranes build up enough energy reserves to have a successful nesting season.
- Humans have a long history of filling in and draining wetlands, which reduces the safe places where cranes may rest and feed. Now the demand for fresh water needs for the fast-growing human population has become a real problem for whooping cranes’ winter home in Texas. Long ago people shot at migrating cranes, and even now cranes are not safe from hunters. That’s because their fall migration may coincide with goose hunting season, and hunters sometimes forget that not all white birds with black wingtips are Snow Geese. Some are whooping cranes! Humans also build tall communication towers and power lines that whooping cranes can’t see. Power line collisions are the biggest cause of crane deaths during migrations. Poachers/hunters have illegally shot some Whooping cranes too.