Back from Extinction
Having rebounded from near-extinction, the whooping crane is truly representative of a species saved as a result of collaborative conservation. Its original distribution included the Great Plains region and extended from the Arctic coast to Central Mexico, from Utah to New Jersey and south to Florida. The decline of the whooping crane in the 20th century Grus americanawas related to the conversion of critical wetland habitats for agriculture as well as persistent and illegal hunting.
By 1941, only 16 birds remained in the wild, all living within a single flock. Captive breeding combined with intensive research and support by governmental agencies, universities, and NGOs over the course of 70 years has resulted in nearly 440 whooping cranes living in nature today. However, this species is far from ‘recovered.’ There is a need for more birds for release and to understand the issues still facing the wild birds and low reproduction in captive individuals.
Conservation in Action
A combination of both domestic and international legal protection, habitat preservation, captive breeding, and on-going conservation efforts between Canada and the USA has been instrumental in saving the whooping crane from extinction. The ability to return birds every year to the wild has required successful breeding and chick hatching and rearing in captive collections. This currently occurs at the Patuxent Wildlife Research Center, the International Crane Foundation (Baraboo, WI), the Calgary Zoo (Canada), and the Audubon Species Survival Center (New Orleans, LA). Although the practical goal is producing cranes for release, these centers also collect basic husbandry and research data to improve species knowledge and chick production.
For the Conservation Centers for Species Survival, the current priority has been to share its expertise in reproductive technologies to both understand and resolve fertility issues in the captive flock. Led by the Smithsonian Conservation Biology Institute, C2S2 is collaborating with USGS colleagues at the Patuxent Wildlife Research Center in assessing semen quality over time and among birds, as well as studying pen design and its impact on egg production. The teams also are exploring the potential value of noninvasively tracking hormones in feces.