Issue 2
Monday, 26 March 2018
Charles Darwin University
PhD candidate Erin Westerhuis
PhD candidate Erin Westerhuis

Mystery bat vanishes into night sky

By Patrick Nelson

The “mystery bat” that swooped over Alice Springs may have been the elusive Bristle Nosed Free-tail Bat, says environmental science researcher Erin Westerhuis.

The PhD candidate was showing onlookers how she uses an Anabat acoustic recorder to tell one species of bat from another, when she picked up an ambiguous signal.

“We positively identified four species and then there was a fifth that was a bit of a mystery,” Erin said.

“It was either a Bristle Nosed Free-tailed Bat or a Little Broad-nosed Bat, but we couldn’t be sure, because their calls are acoustically very similar.”

Erin was at Olive Pink Botanical Gardens this month where she had just given a public presentation as part of “bat night”, when the instrument picked up the unusual signal.

She said just six of Central Australia’s 13 species of micro bat were common in Alice Springs.

“I’ve recorded 10 of these during my survey work, but neither the Bristle Nosed Free-tail Bat nor the Little Broad-nosed Bat is common.”

Erin said most people did not realise how many bats flitted across Central Australia’s night skies. 

“I’ve detected 4000 passes on a summer’s night, which indicates they are abundant and very active. 

“Each one will eat between 100 and 600 insects – mostly moths and beetles – a night.”

Erin is into the final year of a PhD in which she is studying the behaviour of bats and birds along several rivers that start in the MacDonnell Ranges.

“I have trapped 135 bats, observed about 5500 birds and have 144 nights of Anabat recordings to analyse,” she said.