The strange big-eared brown bat was discovered in Brazil's Atlantic Forest in 1916 and then apparently vanished - but it has now reappeared in a Brazilian grassland.
After more than a century, a missing bat is back. The Brazilian species hadn’t been seen since it was first described by scientists in 1916. But a bat collected by researchers in 2018 appears to be a member of the mysterious species, becoming only the second such specimen known.
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| The strange big-eared brown bat (Histiotus alienus) Vinícius C. Cláudio |
In November 2018, Vinícius Cardoso Cláudio, then at the Oswaldo Cruz Foundation in Rio de Janeiro, and his colleagues were conducting a field survey in the Brazilian state of Paraná for the Promasto project, which aims to list all the small mammal species present throughout southern Brazil. Using large mesh nets, the team ensnared a bat with huge, sail-like ears.
It was a male Histiotus bat, Cláudio says, but clearly not the most common local species. The team kept the bat’s remains in the National Museum of Brazil, and the researchers compared its minute physical characteristics with those of other Histiotus bats. When they compared the mystery bat with the sole, century-old specimen of the strange big-eared brown bat (H. alienus) – kept in London’s Natural History Museum – they were surprised by how closely the two matched. They concluded the specimens belonged to the same species.
H. alienus has a unique combination of traits, including the size of its ears, the dark fur on its back and the slightly lighter fur on its belly.
“This bat species was somewhat forgotten by researchers” over the last several decades, says Cláudio.
The discovery provides some data on where H. alienus lives and hunts for flying insects, “but we have virtually no information on the natural history of this species”, he adds.
The only other known sighting of the bat, more than a century ago, occurred in Brazil’s dense Atlantic Forest. The 2018 specimen was found in a very different habitat some 280 kilometres further to the west: The Palmas grasslands, which are interspersed with coniferous Araucaria forests. Both regions are imperiled by human activities; the latter is one of the most threatened ecosystems in southern Brazil, says Ludmilla Moura de Souza Aguiar at the University of Brasília.
Cláudio says more strange big-eared brown bat specimens could be hiding, misidentified, within museum collections.
The finding also highlights our scant knowledge of Brazil’s staggering biodiversity, says Aguiar.
“Especially for bats, we have sampled less than 10 per cent of the Brazilian territory. Therefore, the prospect of unearthing new species and rediscovering existing ones remains substantial,” she says. But Aguiar adds that she is “deeply concerned about the sluggish pace of these revelations in contrast to our rapid rate of environmental encroachment and modification”.
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