Backcountry campers at Fundy asked to help record bat sounds

Backcountry campers at Fundy National Park are being asked to help monitor the park's bat populations. 

They're being asked to record bat sounds while they're camping deep in the woods at Fundy. 

Park officials will then use the recordings to help identify the bat species based on the sounds they make, explained Becky Graham, an ecologist with the park. 

The program will help determine what species are present in the park — and exactly when and where they're there. That will help park officials protect their habitat, including their overwintering caves and the maternity sites where they give birth and raise their young.

While the information is useful to the park, Graham said there's also a bonus for the campers who collect it. An app on their device will alert them when a species is flying overhead — and identify it. 

"So you could be sitting there and you could know a big brown bat potentially just flew overhead because it would show you that, but you would never hear it on your own," said Graham.

In order to participate, campers have to already be registered for a stay in the park. They also have to have a suitable smartphone or tablet. Then, after they arrive at the park, they're given their equipment, including a small recording device. 

Graham said campers are asked to turn on the program just before dusk and run it for a while in the dark, when bats are most active. 

The ultrasonic microphone is activated by the bats' calls and records them as they fly overhead. 

Graham said campers can just go on with their camping activities and let the program run in the background — it doesn't even interfere with the use of the device. Nor does it record human voices, since the recording is activated by a different frequency. 

The information is then downloaded when the campers leave the park and return the equipment. 

Researchers will look at spectrograms of the audio files — they don't actually listen to the recording at all. By looking at the frequencies, slope, and pattern of the bat calls, they can identify the specific species. 

Graham said they did a pilot of the program last year and researchers believe they have picked up all seven species that are native to New Brunswick, including three that are on Canada's endangered species list — the little brown bat, the tricoloured bat and the northern myotis.

Graham said the preliminary results are encouraging, given the state of bats in the province. Most species were decimated by white-nose syndrome, a fungus that grows around the mouth and wings of bats, which was identified in New Brunswick as early as 2011.

The disease is caused by a fungus traced back to a cave near Albany, N.Y. It can wake bats up during hibernation, speeding up metabolism and causing the animals to starve to death.

Donald McAlpine, head of the natural science and zoology department at the New Brunswick Museum, said bat populations are still in trouble in New Brunswick and elsewhere.

McAlpine and a colleague, Karen Vanderwolf, had been going out every year to monitor the overwintering populations — until 2015, that is, when the populations were so low, it wasn't worth the effort, he said. 

About 99 per cent of bats had been wiped out by white-nose syndrome. 

McAlpine and Vanderwolf returned to the overwintering locations last month to check the bat caves but didn't see any tricoloured bats.  

The news for other species was "mixed," he said. 

"It's good in the sense that there are still bats out there. And we did see bats. But there's no sign of recovery at this stage."

He said there's still only "a fraction" of the bats that were there before white-nosed syndrome hit. 

Little brown bats, New Brunswick's most common bat, "seem to be holding their own," said McAlpine. 

"And anything that's out there now has been exposed to white nose and so clearly has some immunity. But there's no real significant recovery at all at this stage."

McAlpine said they didn't see any sign last month of the northern long-eared bat, or northern myotis, which is also on the endangered list. He said there were sightings up until 2015, but the modelling suggests the species could go extinct. 

Although the Fundy research acoustically identified the long-eared and the tricoloured bat, McAlpine didn't find any sign of either during last month's search of overwintering caves.

He's hopeful that the results mean there are bats of both species in the province, but he said identifying species by the sounds they make is tricky work, especially since some species sound very similar. 

McAlpine said the acoustic identification of certain bat species also doesn't provide information about the size or health of the population. 

But once scientists know where the bats are, they can take steps to help protect the habitat, including their overwintering sites and their maternity sites. 

McAlpine said it's important that people not disturb bats during hibernation and when they're raising their young, so if Fundy officials know where the sites are, they can take steps to protect them, he said.