A moth-munching fighter pilot, the Chocolate Wattled Bat (Chalinolobus morio) is a nocturnal insect-buster working mysteriously in the shadows with their inbuilt bug radar (echolocation). Amazingly, these bats call at extremely high frequencies of 50 kHz – way above the 15 kHz limit to what humans can hear!
The soundwaves bounce off objects in the air and are received by the bat, who can use the echoes to determine whether the object is an approaching tree trunk or a tasty moth fluttering around. These aerial acrobats, only as long as your pinkie finger and weighing less than a tablespoon of butter, are hugely important for keeping a lid on insect populations, which helps protect farmer’s crops from pest outbreaks and keep the ecosystem in check.
After a long night out, bats return to their homes to snooze during the day with twenty to several hundred others in small communities. These can be small hollows, spaces under sheets of bark, abandoned bird nests, and sometimes even limestone caves like the ones near Margaret River in the Leeuwin-Naturaliste National Park. Some of them even take advantage of vacant old buildings and roof spaces in urban areas.
Ranging across southern Australia amongst a diversity of rainforest, treeless plain, and woodland habitats, including farmland areas, the Chocolate Wattled bat relies on old-growth trees to roost and have a place to raise their families. Female bats give birth to one or two pups late in spring or early summer, and during this season often form large mother’s groups – or maternal colonies. The pups are huge when born – about a third of the mother’s weight. Can you imagine a woman giving birth to a 20kg baby? Bats breed cooperatively, trusting other members to look after their pups whilst going out foraging at night. After six to eight weeks, the pups are almost fully-grown and are ready to begin pilot training!
Whilst adaptive and resilient, these bats are losing their homes to land clearing and the destruction of old-growth trees with hollows. Urban expansion and roost disturbance cause the bats to look for a new home, but sometimes, especially if there’s not much old-growth woodland left, there are not many places left for them to go.
If you want to help look after the Chocolate Wattled bat, you can help them find a new home by creating a bat box to install near your house or in a tree. Make sure you get a professional to help you design it though – bats can be picky about where they live, and it’s important that the materials you use will last. But in return, they will give you free pest control, all-year-round!
Did you know? Bats have adapted so specifically to flight that they can’t stand on their hind legs. Instead, special tendons in their feet allow them to hang upside down effortlessly!
The State of Victoria Department of Environment, Land, Water and Planning 2017
Kahree Garnaut – Biodiversity Project Officer
Title photo: Terry Reardon