Birds
Whooping Crane
Grus americana · also called whooper
In 1941 there were about 15 whooping cranes left in the world, all in one flock. That the bird still exists at all is the result of one of the longest and most expensive rescue efforts ever mounted for a single species, and it is still not finished.
Overview
Grus americana is the tallest bird in North America, standing around 1.5 m with a 2.3 m wingspan, white with black wingtips and a bare red crown. It breeds in the boreal wetlands of Wood Buffalo National Park in Canada and winters on the Texas coast at Aransas. It is an omnivore that probes wetland mud for blue crabs, clams, frogs, and plant tubers.
The trumpet in the chest
The bugling call that gives the bird its name comes from a windpipe over a metre long that coils inside the breastbone, working like the tubing of a trumpet.
Back from fifteen
Recovery has used captive breeding, costume-reared chicks, and, from 2001 to 2016, ultralight aircraft to teach young cranes a migration route. The wild Wood Buffalo–Aransas flock is now around 540 birds, with smaller reintroduced flocks in the eastern US and Louisiana.
Status
Endangered but slowly increasing. Every whooping crane alive descends from the 15 survivors of 1941, so the species carries very little genetic diversity, and it breeds too slowly for a fast recovery.
Whooping Crane: common questions
How many whooping cranes are left?
There are roughly 800 to 850 whooping cranes in total. About 540 belong to the only naturally wild, self-sustaining flock, which migrates 4,000 kilometres between Wood Buffalo National Park in Canada and the Texas coast. Another 150 or so make up reintroduced flocks, including an eastern migratory population and a non-migratory flock in Louisiana, though these do not yet raise enough chicks to sustain themselves. The remaining birds are in captive breeding centres. Every one of them descends from the 15 birds that survived in 1941, which means the species also carries very little genetic diversity.
Why did whooping cranes almost go extinct?
Two things together. Their wetland habitat across the Great Plains and the Gulf coast was drained and converted to farmland through the nineteenth and early twentieth centuries, removing the shallow marshes they need to nest and feed. At the same time they were shot, both for food and feathers and simply as large, conspicuous targets, and a bird that raises one chick a year could not absorb those losses. By 1941 a single flock of about 15 wintered in Texas. Rigorous legal protection of that flock and its wintering ground at Aransas, starting in the 1930s and 1940s, is what stopped the slide.
What is the difference between a whooping crane and a sandhill crane?
Colour and size are the quickest clues. The whooping crane is white with black wingtips and stands about 1.5 metres tall, making it the tallest bird in North America. The sandhill crane is grey, often stained rusty from preening with iron-rich mud, and is noticeably smaller. Sandhill cranes are also abundant, with hundreds of thousands migrating through the central flyway, whereas a whooping crane is a rare sight. The two sometimes migrate and feed in the same areas, and sandhill cranes have even been used as foster parents for whooping crane eggs in past recovery experiments.
Do whooping cranes really get led by airplanes?
They did, for 15 years. Between 2001 and 2016 the Operation Migration project reared whooping crane chicks in isolation from humans, using hand puppets shaped like adult cranes, then taught them to follow ultralight aircraft. In autumn the pilots led the young birds on their first migration from Wisconsin to Florida, after which the cranes could make the trip on their own. The technique successfully established an eastern flock, but those birds have struggled to hatch and raise their own young in the wild, and the aircraft-led method has been discontinued in favour of other release strategies.