Some surprising bat signals are showing up in the skies above Gwaii Haanas.
But forget the Batman, these winged crusaders appear to be bat species that researchers hadn’t seen in Haida Gwaii before.
It will take time to confirm, but ecologist Carita Bergman says a set of ultrasonic recorders placed across a wide area of Gwaii Haanas last year may have picked up echolocation calls from three or four previously unnoticed species.
One of them, the hoary bat, has a fairly distinct, lower-frequency call. Also found in Hawaii and New Zealand, it forages mostly at sea.
“I think because we haven’t ever looked in those open habitats, we haven’t found it,” Bergman said.
In fact, Gwaii Haanas staff weren’t looking to find new bat species when they hiked and helicoptered to some hard-to-reach places last year and installed 15 ultrasonic recorders across Gwaii Haanas.
Their mission was a response to a real distress call.
Last April, a hiker found a dying bat suffering from white-nose syndrome on a trail near Seattle.
Caused by a white fungus that grows on bats’ noses, wings, and ears, it doesn’t kill bats directly — instead, the irritating fungus repeatedly wakes them from hibernation, leading many to burn up their winter fat and starve.
The Eurasian fungus has killed an estimated seven million bats since it was found in a New York State cave in 2006. Most of the deaths have been in large bat caves across the eastern U.S. and Canada — experts thought they had at least five or 10 years before it spread west.
“That was a big surprise, a big shock,” Bergman said.
Bergman said the idea behind deploying the recorders was to start monitoring was to monitor bats in Gwaii Haanas at a landscape scale, giving researchers a rough idea of how many there are so they will notice if the population ever goes into a sudden decline.
Bat research has a long history in Gwaii Haanas, but it has focused mainly on Hotspring Island, home to the only well-known maternal colony of the Keen’s long-eared bat (its ears are about a quarter of its body length).
Tucked in cracks and crevices near the hot springs on the island’s west shore, the colony includes about 40 females that arrive in May to have their young, which usually fledge in July.
Bergman said the colony declined before the 2012 earthquake, and researchers were concerned it might fall further after several hot springs cooled off.
But the numbers are up again, as Bergman and others can see just by standing along the beach and watching at dusk.
“They have this very fixed behaviour,” Bergman said.
“When they wake up, it’s almost like an aerial highway — they fly down the beach towards the watchmen cabin, and then they cut up and over the main pool.”
Unlike bats in the east, it seems bats in B.C. forests are adapted to overwinter individually or in small groups — they have been seen in root masses, and the hollows of old-growth trees.
That behaviour, and Haida Gwaii’s distance from the mainland, hopefully means bats here are less vulnerable to white-nose syndrome.
“Potentially, we are a refuge,” Bergman said.
Bergman and other biologists have cautioned everyone to stay out of caves on Haida Gwaii, to avoid contaminating them with the white-nose fungus. Anyone who sees a sick or dead bat that looks like it may be infected can report it to 1-855-922-2287, extension 24.
Correction: This story has been updated to reflect the fact that the expanded bat monitoring took place across all of Gwaii Haanas, not a 12 km2 area. Each cell in the monitoring grid measured 12 km by 12 km in area.
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