A new type of bat has been discovered in Alaska, and no one even had to explore a cave to find it.
Bat specimens in storage at the University of Alaska's Museum of the North turn out to be those of a species commonly known as the Yuma bat, or Myotis yumanensis, as scientists call the species.
Some painstaking analysis determined that they had been mistakenly labeled as little brown bats, or Myotis lucifugus, the species most commonly and widely distributed in Alaska.
The dozen museum specimens that turned out to be Yuma bats were collected in the early 1990s in southernmost Southeast Alaska, in the region of Ketchikan and Hyder.
"We didn't know they were here because we didn't know to look for them," said Link Olson, curator of mammals at the museum and one of the discoverers. He is lead author of a study newly published about it in the journal Northwestern Naturalist.
The Yuma bat is now the seventh bat species identified in Alaska. Most of the known bat species are found in southeastern Alaska, though the little brown bat -- the northernmost bat species in North America -- can be found deep in interior Alaska.
The differences between little brown bats and Yuma bats are extremely subtle -- so subtle they sometimes cannot be detected even by bat experts, Olson said. He and his colleagues studied minute details, including DNA, to determine that the collected animals were of the Yuma species. Among the differences is skull shape; Yuma bats possess more steeply slanted foreheads. But even that is not a surefire difference, because individual animals have varying skull shapes, Olson said.
The museum specimens in question were collected in Southeast Alaska, which has damp, cool caves favored by many of Alaska's bats.
That Yuma bats live in Alaska is not a shocking discovery, considering the Yuma bat is known to live just across the border in British Columbia, Olson said. The discovery among museum specimens confirmed a belief that Yuma bats have been "hiding in plain sight," he said.
But there is much to learn about the flying mammals, which Olson's study calls the state's "most poorly studied group of mammals."
"We know so little about Alaska's bats. We don't even know where the majority of them roost," Olson said.
To address that dearth of knowledge, the Alaska Department of Fish and Game manages a bat-monitoring program that was established in 2004.
The study detailing the Yuma bat discovery was published in a special issue of Northwestern Naturalist devoted to the bats of Alaska and northwestern Canada. The 13 studies in the issue were prompted by concerns about a disease that has devastated bat populations in the Lower 48 and eastern Canada and that, biologists fear, might eventually spread much farther north and west..
White-nose syndrome, a disease that has killed millions of bats in eastern North America, results from a fungal infection. The white fungus turns bats' noses white, and about nine of every 10 animals that contract the infection die from it, according to the U.S. Fish and Wildlife Service.
The disease, first detected in New York in the winter of 2006-07, has spread west since then. The government of Canada last week listed the little brown bat and two other species as endangered under that nation's Species at Risk Act because of the toll taken by white-nose syndrome.
Among the many things unknown about Alaska bats, Olson said, is whether white-nose syndrome, "if and when it gets here," might be spread between little brown bats and Yuma bats. "Do they share roosts? We don't know," he said.
The caves of Southeast Alaska are excellent habitat for the state's bats but are also favorable to the fungus that creates white-nose syndrome, Olson noted.
Meanwhile, more is being learned about bats in this part of the world.
A different study published in the same special issue of Northwestern Naturalist concluded that Canada's Yukon Territory is home to two bat species previously undocumented there.
The study used acoustic surveys in several locations in the territory, and analysis was able to distinguish echolocation calls of hoary bats, known by scientists as Lasiurus cinereus, and long-legged bats, which go by the scientific name Myotis volans. Those bats' calls are have characteristics that are different from other bats' calls, said the study, by three Canadian scientists.
Though not previously confirmed in any Yukon location, hoary bats and long-legged bats have been documented in neighboring parts of Alaska, British Columbia and Canada's Northwest Territories, said the study.
Correction: This story originally identified the University of Alaska's Museum of the North as the University of Alaska Fairbanks' Museum of the North.