NZ scientist shines light on hibernating bats

A Kiwi scientist and international colleagues have used high-tech cameras to watch bats as they hibernate. Photo / Paul Cyran

A Kiwi scientist and international colleagues have used high-tech cameras to watch bats as they hibernate.

The methods developed in their study, which captured thousands of hours of footage, could help save global bat species from a disease decimating their populations.

Just published in the journal Methods in Ecology and Evolution, the study marked the first use of thermal imaging surveillance cameras to monitor long-term hibernation behaviours of bats over winter, providing a way to study bats in hibernation without disturbing them.

It found that a bat's movement during hibernation may be key to their survival.

White-nose syndrome is a fungal disease of hibernating bats that has been causing unprecedented population declines in North America since 2007.

More than half of the 42 species of insect-eating bats in the US rely on hibernation as a primary strategy for winter survival and could be adversely affected by syndrome, but researchers have so far been unable to determine why some are at more risk than others.

Two temperature-sensing surveillance cameras in two bat hibernation caves hit by white-nose syndrome were deployed and provided video imagery of hibernating bats over several winters.

The video produced by the cameras allowed the researchers to analyse the patterns of arousal from hibernation in the groups of bats.

"We observed bats from a species that appears to be less affected by the disease are performing group arousals throughout winter hibernation," said Associate Professor David Hayman, of Massey University's Institute of Veterinary, Animal and Biomedical Sciences.

"This result suggests that group arousal during hibernation might be associated with the ability to survive disease, rather than as a precursor to death.

"Group arousal may enable body temperatures less conducive to fungal growth and increase the bats' ability to survive disease."

Bats were often overlooked, but vital animals across much of the world because they were the main predators of night-flying insects, Hayman said.

"This means that bats limit insect damage to many farm crops and unknown numbers of wild plants."

Hayman worked with other collaborating scientists from Colorado State University, and Mathworks, to develop computer methods and sharable software for efficiently processing the thousands of hours of resulting video imagery produced by colleagues at the United States Geological Survey, which has been leading the wider project.

Researchers may now be able to enhance bat survival and predict disease risk to individuals, colonies, populations, continental regions, and species.

Practical applications of the new methods included identifying species-specific behaviours that help bats survive the disease, monitoring for changes in hibernacula of endangered species, and efficiently studying how not only bats, but all cryptic animals cope with environmental change.

Ongoing research aimed to test the possibilities that certain behaviours and winter habitats used by infected bats helped them live through winter.

The study is the latest bat-focused research Hayman has been involved with.

Previous work has linked deforestation in Central and West Africa to Ebola, and also pin-pointed future hotspots of the deadly bat-borne disease.