love thy neighbour Recent human and animal deaths resulting from flying fox borne diseases have captured the public’s attention – yet flying foxes carry out an important role that helps ensure the health of our environment, writes ecologist SHELLEY TREVASKIS.
PHOTOS: LEE K. CURTIS
If you would like to participate in the monthly flying fox count on Straddie please call Shelley Trevaskis on 0400 159 188.
FLYING FOXES ARE WIDELY RECOGNISED AS PLAYING A HUGELY IMPORTANT ROLE IN POLLINATING AND MAINTAINING OUR NATIVE BUSHLAND
traddie is home to two known flying fox “camps” – one in Dunwich, the other in Point Lookout. Some of us are direct neighbours of these camps, and many of us pass by them daily. The Straddie camps host all three species of flying fox that can be found in Southeast Queensland: Black, Grey-headed and Little Red Flying Foxes. All are protected under state legislation. The Grey-headed Flying Fox is offered further protection under both Queensland and Commonwealth law. Due to habitat loss and declining numbers it is recognised as being “vulnerable” to extinction. So far this year, both the Point Lookout and Dunwich camps have harboured good numbers of this threatened species. A nocturnal mammal, flying foxes roost in camps during the day and feed at night. Many of us are familiar with the sight of a “fly out” just after sunset when the bats leave the camp and head out to forage. Viewed against a brilliant orange sky, the sight of a fly out is quite spectacular.
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Flying foxes feed mainly on native blossoms and native fruits. They navigate by sight and locate food by smell. Just like bees and birds, they transfer pollen from tree to tree and disperse native seeds across the landscape as they move between trees. Unlike bees, and most birds, they can travel large distances (up to 50 kilometres a night), while their large bodies transport larger loads of pollen than other pollinators. Interestingly, studies have found that eucalypts produce more nectar at night so as to benefit from flying fox pollinators. Because of this flying foxes are widely recognised as playing a hugely important role in pollinating and maintaining our native bushland. It is estimated that without flying foxes Australia could lose up to 25 per cent of rainforest trees and 50 per cent of koala food trees. At dawn, flying foxes return to their camps. They don’t always return to the same camp, rather, they tend to move between camps across the region. Numbers in camps swell when nearby food resources are rich and diminish at other times.
This is certainly true of the Straddie camps. This year you may have noticed that when the paperbarks started flowering both the Dunwich and Point Lookout camps became crowded. Flying foxes roost in groups for safety and to perform social interactions such as breeding and raising young – a bit like humans in towns and cities. And, like humans, they carry diseases, two of which have captured a lot of media attention.
HENDRA VIRUS Hendra virus was first identified in the Brisbane suburb of Hendra in 1994 and is generally transmitted between flying foxes and horses. It is thought that flying foxes are the natural host of Hendra virus and approximately 30 per cent of the Australian flying fox population carries it. How the virus is passed onto horses is yet to be identified. Humans can contract the virus after coming into contact with the bodily fluids of an infected horse. There have also been two cases where a dog contracted the disease, most likely from an infected horse. To date,
seven people have been infected by the virus and four of those have died. Approximately 80 horses have died as a result of Hendra Virus. A vaccine has been developed to prevent horses contracting the disease. The Queensland Department of Agriculture, Fisheries and Forestry website provides good information about Hendra Virus. (www.daff.qld.gov.au)
LYSSAVIRUS Lyssavirus is a form of rabies. In Australia, three humans are known to have died from the disease after being bitten or scratched by an infected flying fox or microbat. It is generally understood that less than one per cent of the Australian flying fox population carries Lyssavirus. Humans can become infected if they come into direct contact with an infected bat’s saliva or mucus membrane (eye, mouth etc.). Even a very minor scratch can transmit the disease. Urine and faeces are not known to spread the virus. The rabies vaccine prevents Lyssavirus and if administered early, can treat the disease in humans. If untreated, Lyssavirus is fatal. However, bats do not usually approach humans and there is no known risk of contracting Lyssavirus from bats flying overhead SPRING 2013
nor is there believed to be a significant risk of exposure from living, playing or walking near bat roosting areas. People are usually bitten or scratched when trying to rescue an injured, sick or distressed bat, so it is vital that you never, under any circumstances, touch or handle a flying fox or bat of any description. Teach your children this. If you see an injured flying fox or bat, contact Stradbroke Wildlife Rescue (0407 766 052) or the RSPCA (1300-ANIMAL) to arrange for its rescue. If you are bitten or scratched by a flying fox gently wash the wound with soap and water for at least five minutes, apply antiseptic and seek immediate medical attention. If you have a fruit tree that gets raided by flying foxes, net your trees or bag individual fruit. Note that any netting with holes large enough to put your finger through has the potential to entangle flying foxes (and birds) causing them to die a slow and horrible death. It will also destroy your net and put you at risk of handling a flying fox. There are wildlife friendly nets on the market. When many flying foxes are roosting in a camp, noise and smell can be an issue. Take heart – flying fox numbers in the Straddie
camps fluctuate considerably throughout the year, and when camp populations decline, so does the noise and smell. Secretions from scent glands cause the smell, not faeces. Flying foxes invert themselves to defecate, groom frequently and are in fact very clean animals. Flying foxes are a fascinating and ecologically vital native animal: next time you drive or walk through Straddie’s bushland areas, remember that these forests – which give us so much pleasure, clean our air and provide a home to many other animals – are maintained by flying foxes. The diseases carried by flying foxes are scary indeed. However, cases where humans have contracted these diseases are few and can be avoided through awareness and common sense. In order to live peacefully alongside our Straddie flying foxes, we need to be informed and mindful of them. Shelley Trevaskis is one of a group of volunteers who meet every month to conduct an assessment and count of flying foxes in the Straddie camps, as part of a statewide survey coordinated by the Queensland Department of Environment and Heritage Protection. STRADDIE ISLAND NEWS 13