Have you seen any bats flying in your area at dusk or dark? They can be tricky to see, and their swooping flight can be mistaken for swallows or other birds. Bats are an essential part of our ecosystem, being voracious insect controlling predators. Microbats eat mosquitoes and other insect pests, therefore cohabitating with these useful little mammals can be of great benefit to humans. Interestingly, bats are the only mammals capable of accurate and sustained flight, having their forelimbs adapted to flight via a thin membrane. In the Chittering area, we have at least 2 kinds of microbat, the Lesser Long Eared bat, and the Gould’s Wattled bat.
The Lesser Long Eared bat gets its name from its long ears, as up to 25 mm long, the ears can be half as long as its small 50 mm body. An adult can weigh 8-10 g. They eat grasshoppers, crickets and moths, but will also eat other invertebrates. They hunt for food low to the ground, flying around bushes and shrubs to snatch prey from the foliage or the air. This is when you are most likely to see any bat activity.
While hunting, the Lesser Long-eared Bat can fly at only 4 kph, making it one of the slowest flying bats. Low speed combined with high manoeuvrability makes it well adapted for snatching prey from shrubs. It can fly faster when it wants to, reaching speeds closer to 20 kph when commuting.
They roost in caves, tree hollows, ceilings, hollow walls, peeling bark, under piles of bricks, in old hung up clothes and in canvas awnings, usually singly or perhaps 2-3 bats. However, they prefer hollows in big old eucalypts for larger nursery colonies.
They mate in April and the female stores the sperm until August or September. She gives birth in November, often to twins, after gestation of 72-93 days.
Their primary natural predator is thought to be owls, but given they hunt close to the ground it’s not surprising that Lesser Long-eared Bats are often killed by cats. Pesticides are also a problem.
The adult Gould’s Wattled bat is around 100 mm long including the tail, and weighs around 15 g, and is noticeably bigger than the Lesser Long Eared bat.
Males may roost alone or with other species, but females are often found in colonies of 30 or more bats. They roost in tree hollows, bird nests, ceilings or beneath buildings. They eat moths, beetles, flies, and cockroaches, and hunt just below the tree canopy. Although a fast flyer, able to fly up to 36 kph, it is limited in manoeuvrability.
As for all our local microbats, Gould’s Wattled bats go into torpor during winter. Torpor is similar to hibernation, and helps the animal survive the cold months when insects and other invertebrates are difficult to find.
After mating, females can store the sperm for more than 33 days. The gestation period is 3 months, with the young (often twins) born during November or December. The young remain attached to the teat while the mother flies to hunt for food. When foraging for food, a Gould’s Wattled Bat may travel more than 10 km. Natural predators include owls and butcherbirds. Domestic cats are also known to kill these bats.
Bat boxes and microbat boxes can be made and installed to give our precious bat population a safe home. If you are interested, Perth’s very own bat expert, Mr Joe Tonga has a website dedicated to bats of all kinds. His website is gobatty.com.au and there is a lot of very useful information here if you are interested in our small friends. His email is joe@gobatty.com.au
If you find an injured bat please do not handle it yourself, as unfortunately bats may be carrying the Australian Bat Lyssavirus (ABLV) which needs specialist handling by specially trained and immunised carers. Call Kanyana on 9291 3900 or the Native Animal Rescue on 9249 3434. The Chittering Wildlife Carers can give advice after hours on 0498 883 643.
Thanks to ‘Friends of Native Wildlife Inc. for the information on microbats, and the images in this article.
