UNHAPPY about erosion in the whooping crane's last natural habitat in the United States, the National Audubon Society is threatening to sue the US Army Corps of Engineers over dredging in the wildlife refuge where the birds make their winter home. This year 135 of the distinctive white with black-tipped-wing whoopers - the tallest bird in North America - are making their winter home in Aransas National Wildlife Refuge northeast of Corpus Christi, Texas. Besides a site in New Mexico, where a new colony of the birds has been started with man's help, Aransas is the last place where the birds nest in the wild during winter.
But the national environmental organization claims the corps' maintenance dredging of the Gulf Intercoastal Waterway, which runs through the refuge, is causing continued land loss and is posing a threat to the birds.
While not seeking to stop the dredging, the National Audubon Society and one of its local chapters are asking the corps to consult with the US Fish and Wildlife Service about scheduled maintenance dredging in the refuge. The two groups maintain that such consultation is required under the Endangered Species Act and could result in less damaging dredging and dredge-material disposal.
Several studies, including at least one by the corps, indicate that the Aransas wetlands fronting the waterway are eroding at a rate of up to three feet annually. One study states that more than 2,000 acres, or about 18 percent of the whooping cranes' Aransas habitat, have been lost since 1930.
``The erosion issue is one we're as concerned about as anybody else,'' says Ken Bonham, spokesman for the Army Corps district office in Galveston, Texas. He says the corps has not yet responded to the Audubon Society's notice, but added, ``We don't want litigation, and I doubt they do.''
By law the corps has 60 days, or until early March, to respond before a suit can be filed.
Lori Potter, an attorney with the Sierra Club Legal Defense Fund in Denver that is representing the Audubon Society, says her client would prefer to see the corps comply voluntarily with the Endangered Species Act requirements. But she notes that ``under the consultation process, Fish and Wildlife has the authority to require the corps to carry out the dredging in different ways and to mitigate the adverse results'' - and the corps has balked at allowing Fish and Wildlife such a role in the past.
The whoopers have come back from the brink of extinction but remain on the endangered list. By 1941 the cranes had dwindled to only 16 worldwide, but by last year there were about 200.