Article #6 in a Series
by Jane Duden
Back from the Brink?
What is the goal for the eastern population, and how is it going?
Eastern Flock Goal: 25 breeding pairs from 125 Cranes by 2020
Ups and Downs
Since this chart was begun in 2001, you can see how numbers have changed each year. In fact, the total at the last update in Feb. 2016 has dipped to 101 at this writing. Why?
Not only are there many challenges to crane survival, but imagine how hard it is to count and keep track of every individual bird in a population! It's almost impossible to get exact counts. Whooping Cranes can be hard for trackers to find in wetland or marshy habitat — and hard for pilots and counters to see during surveys from airplanes. Sometimes the cranes' remote transmitters stop working, which mean no signals to track them. Cranes are born, and cranes die. Deaths may not be discovered until after snow melts, or predators may leave no remains to find. Some deaths are never discovered. Cranes that have been missing a long time are presumed dead; those cranes are removed from the population totals even though we don't know what happened to them. It takes time, money, experts and citizen scientists to keep track of a whole flock of North America's tallest birds.
Why the Goal?
In 2001, the world's only migratory Whooping Cranes were all in one flock. These birds migrated between Texas and Canada. But what if something happened to that flock? It could totally wipe out this endangered species. That's why nine groups of experts formed an organization called Whooping Crane Eastern Partnership (WCEP) and in 2001 began a daring plan. They started a new flock of Whooping Cranes in eastern North America, where no Whooping Cranes had been for over a century. The goal? To establish a self-sustaining flock with at least 25 breeding pairs ( a pair that nests regularly and has fledged offspring) from 125 Whooping cranes released in the eastern migratory flyway by 2020. At this writing, the number hovers around 100 whoopers in eastern North America.
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| Image Eva Szyszkoski |
Slow Growth
Whooping cranes need healthy wetlands not only in their breeding habitat, but also their wintering habitat and all along their migration route. That includes safety from humans and their activities, disturbances, gunshots, cars, wind turbines, chemical spills, power lines, aircraft collisions, pesticides and more. Like all living things, cranes are subject to diseases, parasites, predators, and extreme weather events, such as the storm that surged through a Florida Wildlife area and killed 17 juvenile cranes from the Class of 2006. Poor reproduction means slow growth too. Cranes in a small, spread-out population have slim pickings when it's time to find a mate and raise babies, not to mention loss of genetic diversity that affects offspring. Cranes don't even start being parents until after age 3. The new flock has faced swarms of black flies that have driven adults off their nests at the Necedah National Wildlife Refuge. They never raise more than two chicks in a year, and the bigger chick often kills the smaller chick in the first days of life.
Looking Ahead
Nearly 250 Whooping Cranes have been released since the reintroduction began in 2001, about 186 of them involved in aircraft training. What will happen by 2020? Will the goal be met? We hope you will keep up with this important conservation story in years to come as cranes will also need to adapt to changing climate. One thing is certain: Species recovery is a long-term challenge.
By Jane Duden
March, 2017
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