New Brunswick biology professor raises concern over shrinking bat population
FREDERICTON (CUP) —
Researchers, including those based
at the faculty of biology at the
University of New Brunswick, are
searching for a way to explain and
stop a phenomenon that has killed
nearly seven million little brown
bats in just six years, pushing the
species to the verge of extinction.
In 2006, scientists in New York state noticed a decrease in the bat population. After surveying some caves, they discovered some hibernating bats had white spots on their muzzles and wings. The fungus has been aptly dubbed white-nose syndrome.
In 2010, Graham Forbes, a professor of biology at UNB and director of the N.B. Cooperative Fish Wildlife Research Unit, along with his team, decided to check local caves to see whether the infection had spread to New Brunswick.
“It was a new species (of fungus) and nobody knew where it came from, in part because nobody has done research on what type of fungus is already in caves or on bats. So we wanted to find out — maybe it was already here and no one looked for it,” Forbes said.
At that time, the team surveyed several caves and found no evidence of white-nose syndrome among hibernating bats. They have also collected data from several bats to determine what types of fungi reside on the bats.
Last winter, when researchers returned, they found symptoms of white-nose syndrome on little brown bats — one of only two types of bats besides the northern long-eared bats that are common to the province.
In one of the biggest caves, the researchers counted 6,000 hibernating bats, including the infected.
Karen Vanderwolf, a graduate student at UNB, has been working with Professor Forbes in conjunction with the New Brunswick Museum, surveying the sites and probing the microclimate of the fungi.
“We confirmed from the research that (white-nose syndrome) wasn't here until 2011 and we also wanted to find out what sort of fungus community was normally on the bats.”
This winter, Forbes and his team did not have to enter the same site to see a different picture — flying bats outside of the cave and dead animals on the snow.
“Most of them died right at the entrance — thousands of dead bats on the ground,” Forbes said.
The scientists counted only 300 bats in that cave — a 95 per cent drop in one winter.
Professor Forbes and Vanderwolf are keeping a close eye on nine bat sites that mostly stretch from the Bay of Fundy to Moncton. Some of the caves are open and easy to get into; others so narrow that researchers have to crawl.
They also have to be extra careful not to transmit the syndrome from the infected bats to healthy ones. The scientists wear special clothing, use clean equipment and spend less than an hour in each cave.
“It spreads on contact, either on the walls or the bats, and because they are (hibernating) in groups, one gets (it) and (it) spreads to the other ones,” Forbes explained. And because New Brunswick doesn't have many caves, bats fly hundreds of kilometres across the province to gather in one cave, transmitting the disease even faster.
Once in the cave, the team counts the bats, which is often quite difficult because of the high ceilings of the cave. Sometimes the researchers take a picture and estimate the number of species.
Then, they carefully isolate one hibernating bat from the group, rub its fungus on a special plate called an agar plate, and hang the bat back. They take the agar plates to the labs for further studying. The researchers also measure and monitor temperature and humidity in the caves.
Cold and wet caves are an ideal environment for the fungus to thrive, Forbes explained. Fungus attaches to the bodies of hibernating bats and starts growing into the skin tissue. As a result, the mammals wake up from itching and irritation in the middle of the winter, instead of April.
“To wake up (in winter), they have to raise their body temperature and they have to burn their fat reserve,” Forbes explained.
“And they are either hungry or thirsty or both; they look for water, for food, (which) takes them outside. There is no food and it's —10°C — they are going to die pretty soon.”
Starvation and dehydration also decreases the immune system of the little brown bats and their ability to fight away infection.
Meanwhile, the white-nose syndrome is spreading fast: it is estimated to spread from 200 to 400km per year. In just six years, the syndrome spread across 19 U.S. states and four Canadian provinces, and it is expected that the infection will expand all over Canada.
The loss of major pest predators will affect flora, fauna and even humans, as the abundance of bugs and mosquitoes increases risks of transmission of different diseases.
Now UNB researches roughly estimate the population of bats in New Brunswick — that was not abundant in the first place — has decreased from 10,000 to 3,000 species.
“For Eastern America, one of the most abundant mammals (will be) essentially gone in five (to) 10 years,” Forbes said.
“It's one of the biggest, catastrophic losses of mammal species that we know of.”
In 2006, scientists in New York state noticed a decrease in the bat population. After surveying some caves, they discovered some hibernating bats had white spots on their muzzles and wings. The fungus has been aptly dubbed white-nose syndrome.
In 2010, Graham Forbes, a professor of biology at UNB and director of the N.B. Cooperative Fish Wildlife Research Unit, along with his team, decided to check local caves to see whether the infection had spread to New Brunswick.
“It was a new species (of fungus) and nobody knew where it came from, in part because nobody has done research on what type of fungus is already in caves or on bats. So we wanted to find out — maybe it was already here and no one looked for it,” Forbes said.
At that time, the team surveyed several caves and found no evidence of white-nose syndrome among hibernating bats. They have also collected data from several bats to determine what types of fungi reside on the bats.
Last winter, when researchers returned, they found symptoms of white-nose syndrome on little brown bats — one of only two types of bats besides the northern long-eared bats that are common to the province.
In one of the biggest caves, the researchers counted 6,000 hibernating bats, including the infected.
Karen Vanderwolf, a graduate student at UNB, has been working with Professor Forbes in conjunction with the New Brunswick Museum, surveying the sites and probing the microclimate of the fungi.
“We confirmed from the research that (white-nose syndrome) wasn't here until 2011 and we also wanted to find out what sort of fungus community was normally on the bats.”
This winter, Forbes and his team did not have to enter the same site to see a different picture — flying bats outside of the cave and dead animals on the snow.
“Most of them died right at the entrance — thousands of dead bats on the ground,” Forbes said.
The scientists counted only 300 bats in that cave — a 95 per cent drop in one winter.
Professor Forbes and Vanderwolf are keeping a close eye on nine bat sites that mostly stretch from the Bay of Fundy to Moncton. Some of the caves are open and easy to get into; others so narrow that researchers have to crawl.
They also have to be extra careful not to transmit the syndrome from the infected bats to healthy ones. The scientists wear special clothing, use clean equipment and spend less than an hour in each cave.
“It spreads on contact, either on the walls or the bats, and because they are (hibernating) in groups, one gets (it) and (it) spreads to the other ones,” Forbes explained. And because New Brunswick doesn't have many caves, bats fly hundreds of kilometres across the province to gather in one cave, transmitting the disease even faster.
Once in the cave, the team counts the bats, which is often quite difficult because of the high ceilings of the cave. Sometimes the researchers take a picture and estimate the number of species.
Then, they carefully isolate one hibernating bat from the group, rub its fungus on a special plate called an agar plate, and hang the bat back. They take the agar plates to the labs for further studying. The researchers also measure and monitor temperature and humidity in the caves.
Cold and wet caves are an ideal environment for the fungus to thrive, Forbes explained. Fungus attaches to the bodies of hibernating bats and starts growing into the skin tissue. As a result, the mammals wake up from itching and irritation in the middle of the winter, instead of April.
“To wake up (in winter), they have to raise their body temperature and they have to burn their fat reserve,” Forbes explained.
“And they are either hungry or thirsty or both; they look for water, for food, (which) takes them outside. There is no food and it's —10°C — they are going to die pretty soon.”
Starvation and dehydration also decreases the immune system of the little brown bats and their ability to fight away infection.
Meanwhile, the white-nose syndrome is spreading fast: it is estimated to spread from 200 to 400km per year. In just six years, the syndrome spread across 19 U.S. states and four Canadian provinces, and it is expected that the infection will expand all over Canada.
The loss of major pest predators will affect flora, fauna and even humans, as the abundance of bugs and mosquitoes increases risks of transmission of different diseases.
Now UNB researches roughly estimate the population of bats in New Brunswick — that was not abundant in the first place — has decreased from 10,000 to 3,000 species.
“For Eastern America, one of the most abundant mammals (will be) essentially gone in five (to) 10 years,” Forbes said.
“It's one of the biggest, catastrophic losses of mammal species that we know of.”
