May 30 2013
Kangaroo Island microbats are currently in a feeding frenzy as they fatten up on insects to see them through the coming winter. If they have taken up residence in your roof or walls, autumn is a good time for a gentle bat eviction before they bunk down for their winter hibernation.
The Foundation for National Parks & Wildlife’s Backyard Buddies program is all about getting more enjoyment from native animals in your backyard. It provides tips and advice on how to make your backyard a haven for our insect-controlling microbat mates.
“Microbats are much more common than you may think,” says Ms Susanna Bradshaw, CEO of the Foundation for National Parks and Wildlife, which runs the Backyard Buddies program. “Right now, bats are eating as much as 40 per cent of their own body weight in a single night or several hundred insects per hour.”
“Many of our microbat species are hollow-dependent which means they live during the daylight hours inside the hollows of trees or branches. Competition from birds, possums and gliders, along with the clearing of many old trees, means that microbats may find the roof or walls of your home the perfect roosting place,” said Ms Bradshaw.
The smallest microbat weighs only 3 grams – about the same as a single serve sugar sachet or a single A4 sheet of paper. If these tiny bats cannot find a suitable hollow, they can slip into gaps as small as 5mm and snuggle down in your roof and walls. This is why artificial roost sites are important as they provide an alternative that everyone can be happy with.
You can purchase a microbat nest box from http://hollowloghomes.com/NESTBOXES.html. Or visit www.backyardbuddies.net.au to find how to build your own microbat roost box, and download a free fact sheet about microbats.
So what do you do if you find resident microbats sharing your home? Fortunately for the little bats, there are humane ways to evict them and now is the time.
In Australia, microbat babies are born in late spring and remain with their mothers until the end of January. Gentle autumn eviction attempts after February and before June make certain that the young are independent. After all, the little bats deserve no harm for taking advantage of ‘faulty’ homes.
“Kangaroo Island microbats are fully protected which might raise the issue of offences and penalties if any are in fact harmed,” explains Ms Bradshaw. “If you want microbats out of your walls, first provide an alternative roost site outside such as a nest box. Then, if done correctly, your walls can become bat free and the little bats will happily stick around your backyard to go about their insect eating work, which is of great benefit to all of us.”
If you have microbats in your walls or roof, visit Bat Rescue Inc. batrescue.org.au/documents/Microbats in the Wall.pdf for detailed information on how to remove them.
A few more things about Australia’s microbats
Microbats use their tail or wings to catch large insects which they carry to their favourite feeding site – look for piles of insect “bits” on the ground.
Microbats live in a variety of roosts that vary between species. Some choose caves or mine shafts or storm water pipes, while others use tree hollows, under bark, cracks in posts, dried palms leaves or junction boxes. They are fussy about conditions and will use a particular site at different times of the year.
Females may fly hundreds of kilometres to special maternity sites to raise their babies.
Microbats make up one fifth of all Australian mammals, and there are more than 60 different types.
Try not to disturb roosting bats in winter. They are very slow to “wake up” and easy prey to cats if the roost is disturbed. Disturbance, and subsequent harm, is the main reason microbats come into care.
Microbats see with their ears rather than their eyes. They produce a sound and ‘listen’ for it as it bounces back from surrounding objects. The time the sound takes to travel back to them tells the bat how close the object is. As the sound bounces off the ground, trees, rocks and houses, the bat ‘sees’ a three dimensional image of its surroundings. The flutter of a tiny moth against a still leaf does not escape the microbat, and leads it to a tasty snack.
When cruising, microbats emit about 10 pulses per second. When an insect is detected the pulses go up to over 100 per second.
If you find a microbat that you think may need assistance – please do not handle it. Call your local wildlife rescue service for advice. Visit backyardbuddies.net.au/Buddy_in_trouble.html for a list of local wildlife rescue groups.