More than five years since the deadly white-nose fungus was first detected in a New York cave where bats hibernate, up to 6.7 million of the animals are estimated to have died in 16 states and Canada, the U.S. Fish and Wildlife Service announced Tuesday.
The estimate, drawn from surveys by wildlife officials mostly in Northeastern states where the disease thrives, confirmed the worst fears of biologists who have been counting dead bats covered in the powdery fungus in mines and caves every winter and worrying whether the little brown bat, the northern long-eared bat and the tri-colored bat will survive.
“We’re watching a potential extinction event on the order of what we experienced with bison and passenger pigeons for this group of mammals,” said Mylea Bayless, conservation programs manager for Bat Conservation International in Austin.
“The difference is we may be seeing the regional extinction of multiple species,” Bayless said. “Unlike some of the extinction events or population depletion events we’ve seen in the past, we’re looking at a whole group of animals here, not just one species. We don’t know what that means, but it could be catastrophic.”
Bats are a top nocturnal predator, picking off night-flying insects that feed on agricultural crops and forests.
US scientists say a human antibody has been shown to protect lab monkeys from the deadly Hendra virus, which has killed 20 horses in NSW and Queensland since June.
Scientists said there were promising signs for the treatment of the bat-borne virus after research was carried out at a highly protected lab in Montana.
The Hendra virus, which was discovered in Australia in 1994, was last week declared endemic in NSW and Queensland after a recent surge in outbreaks.
There have been 18 outbreaks across both states this year, including eight in NSW.
Although no humans have been affected, four of the seven people ever to have contracted the disease have died.
Before this year’s extraordinary cluster, 14 horses had died since 1994.
The research, described in the journal Science Translational Medicine, was done at a high-security lab in Montana, where 14 African green monkeys were injected with Hendra virus.
Twelve of the monkeys were then treated with a human antibody called m102.4, and they all survived while the untreated pair died.
Earlier experiments on smaller animals have also shown efficacy from the antibody against Hendra virus.
After the US study on monkeys concluded in 2010, the antibody was injected in a woman and her 12-year-old daughter in Australia last year as an emergency protection for exposure to Hendra.
While the two survived with no side effects from the treatment, scientists say more study needs to be done before the antibody can be used as a widespread remedy.
“I think this is a very promising therapy, especially when you consider that it was still strong three days later,” said lead author Thomas Geisbert of the University of Texas Medical Branch at Galveston.