Canada's most endangered species is at the centre of a U.S. legal battle after 23 whooping cranes from a Canadian national park — nearly 10 per cent of the last natural flock in existence — died of starvation last winter in Texas due to alleged mismanagement of freshwater flows by a state agency.
The Texas-based Aransas Project, a coalition of conservation groups, has filed notice of a lawsuit against the Texas Commission on Environmental Quality citing "illegal harm and harassment" of the cranes from Wood Buffalo National Park as a result of industrial and municipal water diversions from the Guadalupe River that allegedly robbed the birds of crucial food supplies during the winter of 2008-09.
The coalition, including the International Crane Foundation, claims the restricted flow of the river into San Antonio Bay, in southeastern Texas, on the heels of a recent drought affected salinity levels in Gulf estuaries. They say the salinity levels disrupted a delicate ecological balance and caused a steep decline in the availability of blue crabs and wolfberries — key food sources for the wintering cranes.
State wildlife officers reported the worst whooping crane death toll in decades last spring, describing emaciated and "ratty" birds so exhausted and malnourished some didn't take flight from approaching humans.
Of the 270 specimens that arrived in Texas in the fall of 2008, only 247 survivors were seen heading back to Canada in the spring. Normally just one or two birds is lost during the winter season.
"There is strong evidence that the problems experienced by the whooping cranes are directly caused by the permit programs of the TCEQ that allow too much water to be taken from the Guadalupe River Basin, especially during lower flow conditions," the Aransas Project stated this week in announcing the lawsuit.
"The cranes provide us with an early warning system of the overall health of these coastal ecosystems," said Aransas Project regional director Ron Outen. "But we should remember that the whooping crane is the most recognizable endangered species in the world. Mismanagement of water in the Guadalupe River Basin is destroying the winter habitat of these magnificent birds — and killing them."
North America's tallest bird, the whooping crane's population was down to 22 known specimens in 1941, prompting a joint U.S.-Canada recovery effort that has become a global model for species conservation.
Still, there are fewer than 300 cranes in the world's only wild population, which nests in summer at Wood Buffalo — a UNESCO World Heritage Site straddling the Alberta-Northwest Territories border — before flying 4,000 kilometres to winter feeding and breeding grounds in Aransas National Wildlife Refuge in Texas.
The only other surviving members of the species belong to two separate populations with about 250 individuals in total — a captive flock in Florida and a Wisconsin-based migratory flock trained to follow an ultralight aircraft to Florida each winter as part of a unique, Canadian-led recovery project.
The Texas environment commission has 60 days to respond to the lawsuit notice. A spokesperson for the Austin-based agency said this week that an ongoing water-management review begun in 2007 "will enhance our ability to protect wildlife dependent on these flows."
A 2009 planning document at the TCEQ website, which describes the whooping crane as an "iconic" creature dependent on careful water management, acknowledges that "environmental flows, which include flows in rivers and streams and freshwater inflows to bays and estuaries, have not been addressed uniformly in water development project planning and permitting in Texas."
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