Some of Texas' most exciting bird-watching opportunities are determined by what occurs thousands of miles north. Endangered whooping cranes are born each spring in the wetlands of Canada and migrate to Aransas National Wildlife Refuge on the Texas mid-coast each fall. This year's whooper-watching promises to be especially exciting due to a record number of new chicks.
Whooping crane aerial surveys were conducted in and around Wood Buffalo National Park in Canada where the endangered crane migrates each summer to breed. A record 65 nests and 84 chicks, including 28 sets of twins, were surveyed. This compares to 2006 when 62 nests, 76 chicks and 24 sets of twins were found.
The whooping crane is not only one of the rarest birds in North America; it is also the tallest with adults approaching five feet in height. Males are slightly larger than females. They mate for life and can live nearly 30 years in the wild, and 35 to 40 years in captivity. Cranes are known for their longevity and life-long pair bonds. Adult whooping cranes have snow-white plumage with black wingtips. Their bills are dark olive-gray, which becomes lighter during the breeding season. Whooping cranes are a reddish color when they are born.
This year's record chick production was a result of both high productivity and the high number of nests. According to US Fish and Wildlife Service (USFWS) whooping crane coordinator at Aransas National Wildlife Refuge Tom Stehn, the North American population of whooping cranes now exceeds 500 birds for the first time in 100 years, thanks to conservation and restoration efforts.
The surveys were flown in June by Service Biologist/Pilot Jim Bredy utilizing a Partenavia Observer twin engine aircraft. The aerial observers included both the USFWS and Canadian Wildlife Service whooping crane coordinators Tom Stehn and Brian Johns.
The favorable, warm weather conditions have also been a big factor in the chick's survival in Wood Buffalo National Park in Canada. So far this season, habitat conditions in Wood Buffalo were better than expected with water levels thought to be slightly above average. The weather during the June production surveys was exceptionally warm with no cold, wet weather.
Aerial surveys are conducted to allow for the study of habitats, wildlife and ecosystems, and to provide resource managers with information that often determines important management techniques.
Bredy pilots the Service's plane in all sorts of conditions and says ?these crane surveys are probably the most difficult flying? he does all year. Crane surveys depend on pilot skill and good preparation to be successful. The process takes about five to seven days to complete. When birds are sighted, the pilot makes several passes just above the cranes, trying to keep his eyes on the birds and his instruments at the same time, while avoiding the trees nearby.
All of the whooping cranes alive today; both wild and captive; are descendents of the last 15 remaining cranes that were found wintering in Texas in 1941. Despite the huge increase of birds over the years, the whooping crane is still in danger of extinction. In the United States, the whooping crane was listed as endangered in 1970, and critical habitat was designated in 1978. In Canada, the whooping crane was designated as endangered in 1978.
The current recovery goal is to reclassify the species from endangered to threatened status. However, the National Audubon Society ranks the whooping crane third among endangered bird species, behind the ivory-billed woodpecker and the California condor. For the cranes to no longer need Endangered Species Act protection and be considered "recovered," their population would have to reach about 5,000 birds.
As is the case for so many endangered species, one of the main causes for the birds near extinction was habitat loss. As a result of their population getting so low in the 1940's, one of the biggest threats to the species today is limited genetic diversity. Whooping cranes are also in danger of colliding with power lines, and the threat of chemical spills. Whooping cranes are omnivorous feeders and are very dependent on aquatic food sources and habitat. Displacement and loss of habitat are still major problems for the cranes.
This survey was made possible by the cooperative funding of the Canadian Wildlife Service and the U.S. Fish and Wildlife Service. Service cooperating programs are the Whooping Crane program, Southwest National Wildlife Refuges, Endangered Species and the national Office of Migratory Birds.
