Wing and a prayer: how probiotics might save bat species from a killer fungus

White-nose syndrome is a disease of hibernating bats caused by the fungus Pseudogymnoascus destructans. The fungus grows in cold, humid caves and mines. It matters because infected bats may die in large numbers, threatening species that reproduce slowly and cannot quickly replace lost adults.

The fungus infects exposed skin, especially the muzzle, ears, wings, and other wing membranes. Its white growth is the striking sign described in the article, where biologists found dead and visibly infected bats near Fort Smith. Infection irritates and damages tissue. It also causes bats to wake more often, burn stored fat, lose water, and sometimes leave their roosts during freezing weather.

There is no universally effective treatment for wild colonies. Scientists are testing approaches such as antifungal treatments, vaccines, and beneficial microbes. The discovery in northern Canada shows that the disease remains an expanding conservation emergency, not a problem limited to southern caves.

White-nose syndrome was first recognized in New York State in 2006. It was detected in Canada by 2010, showing that the disease could cross an international border rapidly. By the time of the article’s reported May survey near Fort Smith, in the Northwest Territories, it had reached some of Canada’s northernmost known bat colonies.

That journey covers roughly 3,000 kilometres from the original northeastern United States outbreak area to Fort Smith. The exact speed varies by region and depends on bat movements, connected cave systems, and accidental transport on contaminated clothing or equipment. The article’s central surprise is not merely the distance, but how quickly northern colonies became exposed.

The advance gives scientists less time to protect isolated populations. Monitoring must now reach remote northern caves, while researchers race to test treatments before repeated winter mortality causes permanent population declines. The fungus’s arrival in the boreal north shows that remoteness alone is not reliable protection.

Northern Canadian bats are at risk because white-nose syndrome can move beyond the region where it first appeared. Bats may carry the fungus between hibernation sites, and people can accidentally transport spores on clothing, footwear, or caving equipment. Remote caves slow detection, but they do not create a permanent barrier.

The article describes biologists finding a dead, fungus-covered bat in a cave beneath boreal forest near Fort Smith. They also saw another infected bat nearby. This concrete discovery shows that the fungus had reached a northern colony, not merely passed through a travel corridor. Cold, humid cave conditions then support fungal growth on hibernating bats.

Northern colonies may face especially serious risks because they are isolated and may have few nearby populations to replenish losses. Their remoteness also makes treatment and repeated surveys difficult. Protecting them will require careful decontamination, disease tracking, and rapid testing of methods that can work in wild caves.

Probiotics are beneficial living microorganisms given to a host to support health. For bats, the idea is to use helpful bacteria or other microbes already found on healthy skin. These organisms could become a biological shield against Pseudogymnoascus destructans, the fungus behind white-nose syndrome.

The key mechanism is competition and chemical defense. Helpful microbes may occupy skin surfaces so the fungus has less room to establish. They may also produce substances that slow fungal growth or change the skin environment. Scientists can potentially grow selected microbes and apply them to bats or cave surfaces, although safety and effectiveness must be demonstrated carefully.

This approach is promising because it works with a bat’s existing biology rather than trying to sterilize every cave. It is not yet a guaranteed cure, and effects may differ among species and colonies. The article’s race for a treatment makes probiotics one possible tool among several being investigated.

If scientists cannot control white-nose syndrome, infected colonies may suffer repeated deaths during hibernation. Bats reproduce slowly, so survivors may not replace adults quickly enough. Over time, local populations could disappear, and species with small ranges or few colonies could face severe extinction risk.

The damage would extend beyond the bats themselves. Many bats eat large numbers of night-flying insects, including agricultural and forest pests. Fewer bats could alter food webs and increase pressure on plants or crops, although the size of those effects would vary by place. The article’s dead bat near Fort Smith represents a loss of both an animal and its ecological role.

Scientists are racing to find cures, prevent transmission, or improve survival. Conservation may also require protecting disease-free sites and monitoring survivors. If treatments fail, preserving genetic diversity and finding resilient colonies could become essential, but those steps would not fully replace lost populations or ecosystem services.

Species most vulnerable to white-nose syndrome generally hibernate for long periods in cold, humid caves where Pseudogymnoascus destructans grows well. Little brown bats, northern long-eared bats, and tri-colored bats have experienced especially severe losses in eastern North America. Their vulnerability reflects both exposure and how strongly infection disrupts hibernation.

Not every colony responds identically. Some caves are colder or drier, which may slow fungal growth. Some bats may have stronger immune responses, different hibernation behavior, or skin microbes that inhibit the fungus. Colonies with more survivors can also benefit from inherited or learned traits that improve tolerance. These factors help explain why nearby colonies may show different outcomes.

Survival is not proof that a colony is safe. The fungus can remain in the environment, and conditions can change between winters. Scientists are comparing species and sites to identify protective traits. That information could guide probiotic treatments, habitat protection, and targeted conservation for the most vulnerable bats.

Bats support ecosystems in several ways. Insect-eating species remove huge numbers of insects at night, including pests. Fruit-eating and nectar-feeding bats disperse seeds and pollinate plants, especially in tropical regions. Losing bats can therefore affect food webs, forests, agriculture, and plant reproduction. Their importance makes the article’s northern colony losses especially concerning.

A bat’s skin hosts a community of bacteria and other microorganisms called its microbiome. Some members may compete with harmful fungi for space and nutrients. Others can release chemicals that inhibit pathogens or help maintain a stable skin environment. These natural defenses may influence why some colonies survive white-nose syndrome better than others, although they do not guarantee protection.

Researchers are studying these microbes as possible probiotics or indicators of resilience. Protecting healthy colonies and avoiding unnecessary disturbance may preserve useful microbial communities. The article’s search for a cure therefore includes understanding bats’ existing defenses, not just attacking the fungus directly.