The Goulburn Broken Catchment Management Authority is celebrating birds and bats in 2024 with the ‘Year of the Wing’ community awareness campaign. This month, microbats are featured.
As the only mammals capable of sustained flight, tiny microbats and the larger megabats known as flying foxes, are amazing mammals of the air.
Goulburn Broken CMA Project Officer, Janice Mentiplay-Smith, said the fast and furious microbats dart through the night sky, leaving their roosts at dusk to pursue their insect-based dinner.
“In a single night microbats can eat at least one third of their body weight and mosquitoes feature strongly on the menu,” Ms Mentiplay-Smith said.
“Multiply this by many, many thousands of microbats and it’s not difficult to see how these tiny flying mammals provide a valuable pest control service.”
There are 12 species of microbat that call the Goulburn Broken catchment’s Grey Box Grassy Woodlands home. Microbats are placental mammals and not marsupials meaning they don’t have a pouch and give birth to fully developed young. There are more than 60 species of microbat in Australia.
Microbat babies are called pups and are born in late spring and are feed upon their mother’s milk until mid-summer. At birth, the pups are approximately one-third the size of their mother; the equivalent of a human giving birth to an approximately 20-kilogram baby!
“These tiny mammals weigh between 3-150 grams, depending on the species. All microbats use echolocation ‘pulses’ to locate and gauge the distance between themselves and other objects, including prey,” Ms Mentiplay-Smith said.
“They emit a sound and listen for it as it bounces back. The time taken for the pulse to return indicates the location of the object. Normally a microbat emits about 10 pulses per second. When an insect is detected these increase to more than 100 pulses per second.”
“During summer and autumn when insects are plentiful, microbats fatten up in readiness for winter. Once the nights become cooler and insects disappear, microbats lower their body temperature and enter a torpor, a form of short-term ‘hibernation’ and survive off their stored fat until spring.
“If you know the location of microbats settled into their torpor over winter, be careful not to disturb them. Emerging from torpor too soon subjects them to predation and forces them to draw upon valuable fat reserves. If disturbed too many times they will deplete their stored energy and will not survive until spring.”
Microbats roost in tree hollows, behind pieces of bark and in caves. Dead trees are vitally important for microbats as they contain plenty of roosting places. Even small dead trees of just 20cm in diameter are extremely valuable. Do all you can to keep this precious resource on your property!
The lack of tree hollows in the landscape mean microbats need to roost in cracks in fenceposts, storm water pipes, culverts and within house and shed roofs and walls. Microbats will also roost in nest boxes. Visit ausbats.org.au for information on how to build and install a bat box.
You can read more about microbats in “the Mammal Book’, a 58-page booklet featuring beautiful photographs and informative text. To view a copy, visit the website The Mammal Book - GB CMA - Goulburn Broken CMA
Throughout March, April and May, various Bat Nights are held by the Australasian Bat Society at various locations. Everyone is welcome to attend and learn more about the marvellous world of microbats. Visit Ausbats - Welcome to the Australasian Bat Society to find out more.
Gould’s Long-eared Bat, Gould’s Wattle Bat, Lesser Long-eared Bat, Chocolate Wattle Bat and pup. Photos William Terry.