Creature with ‘enlarged’ ears was elusive for 100 years. Then it was seen fluttering

After a 100-year absence, a big-eared Brazilian bat has fluttered back into the spotlight.

The elusive winged creature, which has only officially been spotted once before, has now been captured by researchers, according to a study published on Aug. 14 in the journal Zookeys.

The bat, named Histiotus alienus, is characterized by its mid-sized body, multi-colored fur and large, triangular ears.

It belongs to a genus of around a dozen species in Latin America that, though the subject of several studies, remains poorly understood.

British zoologist Oldfield Thomas first encountered Histiotus alienus in 1916 while in Santa Catarina, a southern coastal state in Brazil.

Thomas, then “one of the world’s foremost taxonomists,” according to the Smithsonian, took a few measurements and briefly described the winged creature. But a more comprehensive study was never completed.

Over the next century, Histiotus alienus evaded the clutches of researchers, seemingly vanishing into thin air.

But then, in November 2018, researchers found the long lost creature in a nature preserve in the Brazilian state of Paraná. The reserve is a large, protected area composed of grasslands and pockets of forest.

As part of a bat survey, researchers placed mesh nets on forest edges, across trails and over bodies of water to catch the flying animals.

The nets were open for about six hours each night and were regularly inspected about every 30 minutes.

Of the bats caught throughout this process, one turned out to be the rare Histiotus alienus.

The captured bat was euthanized, preserved in an alcohol solution and whisked off to a museum in Rio de Janeiro to be studied.

Detailed analysis revealed the creature, an adult male, had “greatly enlarged” ears, a broad muzzle and brown, olive and yellow patches of fur.

Using data from 184 other specimens in the genus, researchers were able to determine the creature indeed belonged to the Histiotus alienus species.

Given it was discovered about 170 miles from the bat’s sighting a century ago, researchers revised its distribution to include a larger area.

But, given only two sightings have now been recorded, much else about the bat remains unknown.

Further sightings, hopefully not limited to hundred-year intervals, can help expand upon the research.

Worldwide, there are over 1,400 species of bats, the only mammals that can fly, according to the U.S. Department of Interior.

Their characteristically large ears enhance their ability to echolocate, the method by which bats observe and navigate through their environment, according to the journal Scientific Reports.

This story was originally published August 17, 2023 at 2:43 PM with the headline "Creature with ‘enlarged’ ears was elusive for 100 years. Then it was seen fluttering."