Scientist rediscover bat that hasn't been seen in 100 years

The Strange Big-eared Brown Bat, Histiotus alienus. (Cláudio et al.)

The Strange Big-eared Brown Bat was last seen in 1916 after it was captured in southern Brazil. But after more than a century of its absence, the elusive species has been rediscovered.

The findings were reported in a new study published in ZooKeys on Tuesday where researchers detailed their field expedition that led them to the bat, also known by its scientific name as histiotus alienus.

In 2018, a group of scientists from the Federal University of Parana in Brazil initially compared the bat to the Tropical Big-eared Brown Bat, histiotus velatus, since that was the native species commonly found in Palmas Grassland Wildlife Refuge. However, after further evaluation researchers concluded it was incompatible to histiotus velatus and hundreds of other similar-looking species it was compared to.

Scientists concluded the bat found was indeed histiotus alienus; the enlarged eared, brown bat, measured roughly at 100 to 120 mm in length. It's known for living in varied environments like araucaria moist forests to grasslands.

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The most recently captured bat was found 280 kilometers from where the first reported bat was found in Joinville, Brazil. The study pointed out despite this dispersion in the population it does not mean the species' conservation has been improved. Since the species has only been reported on twice over the last century, the International Union for the Conservation of Nature (IUCN) has classified the bat as "data deficient," meaning there isn't sufficient information to assess the species' risk of extinction.

This can be troubling, the study authors says since the bat's habitat has faced land occupation for years and in the Palmas region where the rediscovered species was found have been impacted by the growing energy sector.

Additionally, the study authors say this rediscovery emphasizes the need for further research on histiotus, the neotropical genus of bat as a whole, since various other species also have old and unclear biological classification.

"The general results of our morphometric analysis indicate some degree of similarity among species in the shapes of their skulls, which demonstrates the usefulness of external morphology in correctly identifying Histiotus species," the study says.