Disorienting fungus fatal to bats

UC DAVIS (US) — The nation’s bat population is under serious assault by a deadly fungus that first appeared in New York State in 2006.

“If we lose bats, we lose keystone species in some communities, predators that consume enormous numbers of insects, and beautiful wildlife species that are important parts of North America’s biodiversity,” says Janet Foley, professor of veterinary medicine at the University of California, Davis.

White-nose syndrome (Geomyces destructans), normally lives in soil, but travels to cave walls where bats hibernate in winter infecting facial skin and wing membranes.

Sick bats appear to be coated with frost. They fly more than normal, using up fat reserves, and causing them to lose water at a faster rate than normal. Disoriented, they move to exposed places, such as cave entrances, and eventually starve, freeze, or die of dehydration.

Details are reported in the early view of the journal Conservation Biology.

Bats are essential members of natural ecosystems, hunting insects, pollinating plants and scattering seeds, Foley says.

“Bats do the jobs at night that birds do during the day. But because they are most active in darkness, few people are aware of how many bats live around us and how valuable they are.”

The first infected bats were found by a cave explorer near Albany, N.Y., in February 2006. Since then, infected bats have been found northward to Ontario and Quebec in Canada, south to Tennessee and west to Oklahoma.

White-nose syndrome is expected to cross the Rocky Mountains and enter California in the next several years, making vulnerable the 23 species of bats that hibernate in the state’s caves.

The fungus does not appear to be a threat to people or animals other than bats.

“In the three years since its discovery, white-nose syndrome has changed the focus of bat conservation in North America,” says Foley.

“A national response is required, and our epidemiological roadmap is designed to help emerging state and national plans to combat white-nose syndrome across the United States.”

Recommendations to combat the fungus include:

  • An outbreak investigation network that would establish a standard diagnosis and case definitions.
  • Bat population monitoring.
  • Improved public awareness of the problem.
  • Further studies of chemical and biological agents to kill the fungus, but not yet proven safe for bats.
  • Further study of treatments for similar diseases.

“Scientists, policymakers and members of the public will all have a voice in the coming debate over the best course of action,” Foley says.

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