Thursday, 5 February 2015

Batting For Australia

 What an amazing service bats do for this nation and what little thanks they get for it! Most of us are familiar with larger bats, the flying foxes, as we can witness their spectacular flight formations over the Sydney sky at dusk.  These animals provide vital ecological services. They are important pollinators (the sole pollinators of certain tree species) and they also disperse seeds which helps keep our forests viable. Their natural diet is native fruit and pollen.
 What you may not know is that we also have nearly twenty species of microbat in our area.  Most of these are very small...some are as tiny as your thumbnail and weigh less than a 10 cent coin!  Most microbats eat only insects and some thrive on mosquitoes - scoffing down thousands every night.  In fact, if bats ever became extinct, insect numbers would soon reach plague proportions (they already save us billions of dollars a year in agricultural pest control). So why do humans get so illogically squeamish at the very thought of these cute and beneficial creatures?  Well many people wrongly associate bats with vampires, witchcraft and black magic but the only spells I’ve seen them cast in real life are those of wonder and fascination.  Bats are warm blooded, placental mammals.  Like us, they usually have one baby at a time, with occasional twins. They carry their offspring around with them for about three weeks after they are born, and continue to breast-feed them for up to 6 months. Although flying foxes have good sight and all bats can see with their eyes, the really amazing thing about microbats  is that they fly and hunt in darkness using echolocation.  They basically emit ultra sonic calls and by repeatedly scanning the echoing sound patterns, can mentally construct an accurate image of the environment in which they are moving as well as their potential prey. No wonder they have such big ears!
 Until recently there was a colony of around 22,000 Grey-headed flying foxes roosting in the Royal Botanical Gardens. It became quite a tourist attraction as it was possible to observe the chattering, upside-down hanging, melee during daylight hours.  Unfortunately, the Botanical Gardens Trust decided that the bats were causing too much collateral damage to their exotic trees and with Federal Government approval, moved them on, using loud recorded noises. Grey-headed flying foxes are a threatened species, protected under both state and national environment law. Thankfully, it seems, many of the relocating bats have been welcomed by the Centennial Parklands Foundation and small colonies have even made themselves at home on the Peninsula. It is recommended that people do not disturb or handle bats though, as, like all animals, including cats, they can carry disease.

Endangered Grey-headed flying foxes roost near a busy road at Balgowlah

 Microbats roost inside tree hollows and sometimes under rock overhangs, bridges and culverts during the day.  Their main threat is loss of habitat and competition for roosts from Indian Miners and feral bees. They are also at risk from predation by cats and rats and are sensitive to pollution, loud noise and bright lights.

Footnote: Amazingly, our part of the world can even boast a bat that fishes....the Large-footed Myotis.  It forages over pools of water in rivers, lakes and small streams, using its over-sized feet to scoop along water surfaces for small fish and aquatic insects. It has recently been found at Narrabeen Lagoon.

A Lesser long-eared bat

People in "the know" believe that bats are the coolest animals on the planet. To find out more and to help with conservation efforts check this link.. Sydney's bats