An evolutionary success Echolocation

ATS are a highly successful group of . They Also known as fruit or flying-foxes, megabats (despite Echolocation (also called biosonar) is a complex biological Bhav e survived for over 50 million years, and with their their canine features) are mostly vegetarian and feed almost sonar system used by that enables them to remarkable ability to adapt to their environment have exclusively on fruit, nectar, navigate and to hunt for prey in darkness. They do this by colonised almost every corner of the globe. Worldwide, and pollen. Although some emitting intense ultrasonic sound pulses (inaudible in most there are more than 1,100 species of bats. They comprise of the world’s megabats are cases to humans) and with their modified and sensitive ears, about twenty per cent of the world’s mammals, and in quite small, the majority can interpret the echoes that bounce back to them from are larger than microbats, numbers of species, they are exceeded only by surrounding objects. This allows them to locate and identify with a few species weighing rodents. All bats are nocturnal, and are divided into two with great clarity objects and prey in their main groups: the generally larger fruit bats (megabats), and more than 1.5 kg, and with immediate environment – this sensory mechanism is so the smaller, mostly, insectivorous bats (microbats). wingspans exceeding 1.5 efficient that objects as small as a midge or as fine as a metres. Megabats typically More facts spider’s web can be detected by microbats.

forage for food by night and  Bats are the only mammals that can fly. roost by day – sometimes in colonies of tens of thousands of  Being unique among mammals, bats are classed in individuals. Australia has nine species of megabats; they live their own order, Chiroptera (meaning "hand-wing"). in the eastern and northern parts of the country, with three  The bat’s wing bones can be likened to a human arm, occurring in : Black Flying-fox ( but with the fingers of the hand greatly elongated. alecto), Little Red Flying-fox (Pteropus scapulatus) (above)  Baby bats (called pups) feed on their mother’s milk; in and Northern Blossom Bat (Macroglossus minimus). most species pups are born large and develop rapidly. With few exceptions, megabats do not use echolocation,  Bats have a very slow reproduction rate, often just they navigate and find food by sight and smell. one pup per year; some species have twins.  Microbats Bats are clean and groom themselves meticulously.

 Bats are long-lived – up to 20 years or longer. Microbats are usually smaller, and primarily insectivorous,  Bats choose a variety of roosting sites, which include but some species – including the large, carnivorous Ghost Echolocation calls of bats are species-specific (though caves, tree hollows, abandoned birds’ nests, under Bat (Macroderma variations in frequency, length and amplitude can occur loose bark, amongst foliage, and in buildings. gigas), classified as within species depending on the situation and locality); this  The endangered Kitti’s Hog-nosed Bat (also known as vulnerable and found enables bat identification to be effected using a bat detector the Bumblebee Bat), found in Thailand and Burma, is only in Australia – will – a device designed to detect bat activity and distinguish (by length) the world’s smallest mammal. catch and eat animals species by converting their ultrasonic signals to audible

such as birds, reptiles frequencies. This is a much less invasive way to identify bats and frogs, as well as than capturing them with mist nets, hand nets or traps.

other bats. A few species feed on small Use of echolocation is not confined to microbats: toothed whales fish, which they snatch with their feet from near the surface (including dolphins and porpoises) use this system for hunting and of the water. Others feed on fruit and nectar. Three species of microbats, found in Central and South America, feed on navigation. A simpler form of echolocation is used by the blood; these bats are called vampire bats. Aerodramus genus of swiftlets (known for their nests made of Despite having good eyesight, microbats have developed a saliva used in bird’s nest soup); South American oilbirds sophisticated and ingenious way to navigate and locate prey (Steatornis caripensis); certain species of shrews and tenrecs; in the dark. This technique is known as echolocation and it and members of the genus of megabats. The technique exceeds any navigation system yet developed by humans. can also be learned by blind people as a means of navigation. Bats of south-west WA Threats to bats

Nine bat species occur in south-west WA, all are microbats In many regions of the world, bat numbers have declined The Amazing Life and all have been recorded in the Perth region: drastically. Of the  80 species of bats in Australia, 43 are of  White-striped Freetail Bat (Tadarida australis) locally or nationally threatened. Reasons include habitat  Southern Freetail Bat (Mormopterus planiceps) destruction; fire; pesticides; feral animals (such as European  Gould’s Wattled Bat ( gouldii) honeybees) occupying tree hollows that bats use for  (Chalinolobus morio) roosting; disturbance at caves and other sites where bats

( regulus) roost; and persecution driven by fear and ignorance.  Western False Pipistrelle ( mackenziei) Benefits of bats  Lesser Long-eared Bat ( geoffroyi) Over millions of years, bats have evolved as part of the  Gould’s Long-eared Bat (Nyctophilus gouldi) natural environment, playing an essential role in the  Western Long-eared Bat () functioning of the ecosystem. Fruit-eating bats disperse The most common include the highly adaptable Gould’s seeds and, accordingly, help to regenerate native plants. Wattled Bat, found over most of Australia and which uses a Nectar-eating bats are important pollinators of the many variety of roosting sites including tree hollows; White- species of flowering plants at which they feed. Insect-eating striped Freetail Bat, one of the few bats whose echolocation bats can consume up to half their body weight in insects per calls are audible to the human ear (a metallic “ting…ting”); night (including mosquitoes, midges and other pest insects) and the Southern Forest Bat (below) a small species that and are vital in controlling insect numbers. For these displays great aerial reasons alone bats should be valued and protected as manoeuvrability. One indispensable components of natural communities.

of the least common in the Perth area is the Destruction of bat habitat, along with tree hollows in which they fast-flying Western roost, means that these exceptional animals need our help. One False Pipistrelle, which way we can do this is to provide them with roost boxes specially is endemic to south- designed for bats. Bat boxes can either be purchased or made by

west WA.

the handyperson – instructions on how to do this, where to

position them etc. are on the internet. This is an ideal project in

Bat myths which children can be involved – it will teach them not only the

 “Bats are blind” – bats are not blind; most bats, importance of bats, but to care for the environment in general.

especially megabats, have good eyesight.  “Bats get tangled in people’s hair” – this does not Further reading happen; bats would do all they can to avoid this. Churchill, S. (2008) Australian Bats. Jacana Books.  “Bats are rodents” – bats are not rodents; they are Richards, G., Hall, L., Parish, S. (2012) A Natural History of Australian Bats – Working the Night Shift. CSIRO Publishing. more closely related to primates than rodents. Australasian Bat Society: http://ausbats.org.au  “Bats suck human blood” – only three species of bats Bats in Western Australia: http://gobatty.com.au (vampire bats) feed exclusively on blood, which they lap (not suck) after making a small cut in an ’s Photos: Southern Forest Bat and Lesser Long-eared Bat by Jesse Young;

skin. One species drinks the blood of mammals (rarely Little Red Flying-fox, illustrations and text by Bryony Fremlin.

humans), the other two favour the blood of birds. © Friends of Forrestdale (Inc.) 2013