Rare cranes in precarious situation

Feb 4, 2010 | Corpus Christi Caller-Times by Editorial | TAP In The News

This winter will be a hard one for the whooping crane, one of the most endangered species in the world. The last remaining natural flock of the rare birds took a devastating loss last year at its wintering grounds at the Aransas Natural Wildlife Refuge. The flock lost 23 birds, a heavy blow to a species that only counts an estimated 263.

This November-to-March wintering season is expected to be just as hard on the big birds. At about 5 feet, they are the tallest in North America.

The immediate cause of last winter’s die-off was the scarcity of blue crabs, the chief source of food for the birds during their time along the Gulf Coast. But some environmentalists believe the real cause is far upstream from the coastal marshes where the birds winter.

In December, a coalition of environmentalists filed paperwork in preparation to suing the state, alleging that regulators have allowed too much water to be taken out of the Guadalupe-Blanco river watershed, to the detriment of the cranes. Developers of subdivisions, industry operators and agricultural interests far from the Gulf Coast — the Guadalupe-Blanco watershed includes parts of the Hill Country may not think of their own water needs as competing with the water demands of whooping cranes. But the survival of the species is connected with the health of the river.

In Texas, where the demand for water is ever increasing from growing cities and suburbs, guarding the downstream flow of rivers is often a thankless task. Even though the Legislature has mandated that river authorities set aside freshwater flows for wildlife needs, to much of the public, water that is allowed to be released from upstream reservoirs is “wasted.” Even in Corpus Christi, whose tourist industry depends heavily on a healthy coastal environment, the release of freshwater from the city’s reservoir at Choke Canyon is still disputed in some quarters. But the necessity of protecting downstream flows is becoming ever clearer as underlined by the stress being placed on the last surviving members of a magnificent species.

Which is not to say that the allegations in the suit will be easy to prove. The scarcity of blue crabs came after one of the hardest droughts in South Texas history. The drought placed stress on every species in the region. And the blue crabs, which help the birds restore their strength from the long migration from Canada, still haven’t come back in the numbers necessary to feed the birds. Some of the big birds already have begun foraging outside the refuge boundaries, using up more of their energy just in finding enough food. Refuge officials have plans to put out food, the same kind that cranes in zoos are fed. But that may not be the answer for a flock that naturally feeds on the rich food of blue crabs.

Defendants in any lawsuit can well point out that the whooping cranes, despite being few in number, have actually increased since their low point in 1941 when only a handful existed. But the species is still in a precarious position. “I feel that we’re probably going to have a die-off,” Allan Strand, field supervisor for the U.S. Fish and Wildlife Service in South Texas, said last week. “It’s conceivable that we could have a significant die-off.”

The species has been hit hard by a drought, a natural occurrence in South Texas. But the big birds’ situation shouldn’t be made worse by being squeezed out of their share of freshwater river flows, if the evidence says that is happening.

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