Virus Poses Threat to Endangered Whooping Cranes

Technician Barbara Niccolai holds the struggling, fuzz-covered bird by the legs with her right hand and by the torso with her left hand, while the veterinarian slips a white hood over its head.

“They don’t like this,” Niccolai whispers, as the little bird bucks in her grip. As soon as the hatchling whooping crane can’t see, Niccolai and colleague Glenn H. Olsen raise the face veils on their bizarre white shrouds and continue its checkup.

It’s vital that the chick, one of only a few hundred surviving, not see humans or hear their voices, lest it bond to them. It’s one part of the meticulous care the cranes get at this government refuge.

But a new menace has emerged to threaten these endangered creatures: West Nile virus.

The large, gawky whooping cranes--which number only a few hundred in Canada, Florida, the U.S. Geological Survey research center in Laurel and a few other places--have so far not been infected, experts say. But they are susceptible to similar mosquito-borne viruses and are right in the microbe’s path.

Last year, West Nile came within eight miles of the 12,800 acres of marsh and woodland of the Geological Survey’s Patuxent Wildlife Research center, when a crow died of it, according to Olsen, the Patuxent cranes’ chief curator.

While crows have been the virus’ chief victims in the wild--with a mortality rate of almost 100%--the cranes have shown susceptibility to West Nile’s close kin, eastern equine encephalitis, Olsen said.

About half a dozen Patuxent cranes died during an equine encephalitis outbreak a decade ago, and those at the refuge are vaccinated against it every summer.

But there is no vaccine for West Nile, which has infected the whooping crane’s cousin, the sandhill crane.

“We’re very concerned about the West Nile virus, because we don’t know how serious a health threat it poses,” Olsen said. “We do know that [the cranes are] susceptible to other mosquito-borne viruses.

“It could potentially wipe out the population of these birds, because you could get [numbers] so low that the population that’s left is really not viable,” he said. “That’s the problem we have.”

West Nile comes in the midst of elaborate efforts to increase the number of whooping cranes in the wild. This fall, conservationists will use 15 Patuxent birds, led by an ultralight aircraft, to try to establish a wild flock and a migratory route from Wisconsin to Florida. The last thing the project needs is its cranes dying of the virus, Olsen said.