Endangered Whooping Crane Numbers Drop For First Time Since 2001
Public Asked to Report Bird Sightings During Northward Migration
The trumpeting sound of cranes overhead is a cherished sound of spring in Texas, but as endangered whooping cranes depart Texas this spring en route for breeding grounds in Canada, fewer birds will be making the trip.
According to Tom Stehn, whooping crane coordinator with the U.S. Fish and Wildlife Service, 2008-2009 was the worst winter on record in terms of bird deaths for the last remaining wild flock of whooping cranes (Grus americana). Stehn is based at the Aransas National Wildlife Refuge near Rockport, Texas where the whoopers return every winter. The birds spend summers at Wood Buffalo National Park in Canada.
Stehn reported that “…total winter mortality is estimated at 6 adults and 15 chicks, totaling 21 whooping cranes, a loss of 7.8 percent of the flock that was a record 270 birds in the fall.” When added to 34 birds that left Texas in spring 2008 and failed to return in 2009, Stehn said 20 percent of the flock was lost during the last 12 months. The upshot is that only 249 birds will make the trip north this year. After an encouraging multi-year comeback in which flock numbers have grown each year, this marks the first year bird numbers have declined since 2001.
Stehn attributes the winter losses to poor habitat conditions in wintering grounds on the middle Texas coast. Low rainfall in 2008 resulted in saltier bays and fewer blue crabs, the primary food source for wintering whoopers. In addition, according to Stehn, whoopers are further stressed when cranes must leave the bays to fly inland seeking fresh water. Several emaciated whooping crane carcasses were found, and refuge staff even took the unusual step of providing supplemental feeding over the winter in addition to burning upland areas to make acorns more available.
Occasional set-backs aren’t new to the whooping crane recovery story, a species that numbered only 49 as recently as 1975, according to Lee Ann Linam, biologist in the Wildlife Diversity Program at Texas Parks and Wildlife Department.
“Although whooping crane numbers have experienced an amazing upward climb since conservation efforts began in the 1930s, over the course of their recovery we have occasionally seen short-term dips in the population,” Linam said. “The losses this winter do emphasize the important role Texas has in maintaining the health of its bays and estuaries, especially in safeguarding stream-flow during low rainfall periods.”
Stehn seconds those concerns, noting poor feeding conditions on the wintering grounds have often been followed by a poor reproduction season in Canada.
Texans can also help safeguard whooping cranes during their migration through Texas in the spring and fall. Migrating cranes usually depart the Texas coast in late March and early April, riding southerly winds on a northwest path encompassing cities such as Austin, Fort Worth, and Wichita Falls.
Citizens are being asked to report sightings of whooping cranes in flight by calling toll-free (800) 792-1112, extension 4644 or emailing firstname.lastname@example.org. If whoopers remain overnight in small wetlands, citizens are encouraged to minimize disturbance at the site.