The first winter after Hurricane Harvey ravaged the Texas Gulf Coast, an estimated 505 whooping cranes arrived on their Texas wintering grounds after migrating 2,500 miles from their breeding grounds in Wood Buffalo National Park in Canada. Each fall the birds make their way back to Aransas National Wildlife Refuge and surrounding habitats, where they spend the winter. Once they have arrived, wildlife biologists with the U.S. Fish and Wildlife Service survey the birds by air and analyze population trends.
Biologists have completed analysis of aerial surveys of the Aransas-Wood Buffalo whooping crane population done last winter. A switch in aircraft the previous winter and a shift to surveying later in the winter when a larger proportion of the population had arrived helped improve accuracy of the counts. Preliminary data analysis indicated 505 whooping cranes, including 49 juveniles, in the primary survey area (approximately 153,950 acres) centered on Aransas National Wildlife Refuge near Austwell, Texas. An additional 21 birds were noted outside the primary survey area during the survey. This marks the 6th year in a row that the population has increased in size and the first time the population has topped the 500 mark.
“Breaking the 500 mark for this wild population is a huge milestone”, stated Amy Lueders, the Service’s Southwest Regional Director. “Seeing this iconic bird continue to expand demonstrates how the Endangered Species Act can help a species recover from the brink of extinction. I have to credit our biologists and our partners and local communities who continue to invest so much time and effort to improve our ability to make sure future generations have the chance to marvel at the beauty of these amazing wild birds.”
The U.S. Fish and Wildlife Service has implemented several small changes that have greatly improved the agency’s capacity to survey the birds. “After two years of testing a shift of our December survey timeframe to later in the winter, we believe our previous survey estimates were likely low given that not all the whooping cranes had completed migration by mid-December. We had indications of a later than expected fall migration over the last several years via migration reports and telemetry data. This is the first year that we have based our winter abundance estimate from a February survey timeframe rather than a December timeframe. It may seem like population numbers jumped more than usual, but in reality we are just capturing a more complete proportion of the population, with most birds having completed migration by early February” stated U.S. Fish and Wildlife Service Whooping Crane Coordinator Wade Harrell.
Harrell said biologists will continue to conduct flights in late January and early February for future surveys. He also stated that staff at Aransas National Wildlife Refuge continue to make progress in recovering from the impacts of Hurricane Harvey. “The good news is that the coastal marsh that supports our wintering whooping cranes was not significantly damaged by the hurricane and recovered quickly from any impacts, demonstrating how resilient intact wetland habitats can be.”
Whooping cranes are one of the rarest birds in North America and are highly endangered. Cranes have been documented to live more than 30 years in the wild. Adults generally reach reproductive age at four or five years, and then lay two eggs, usually rearing only one chick.
More information about the survey and whooping cranes can be found on the Aransas National Wildlife Refuge website at http://www.fws.gov/refuge/Aransas/ or by calling the Aransas National Wildlife Refuge Visitor Contact Station at: (361) 349-1181.
