About Grey-headed flying fox
Flying foxes are nomadic mammals that travel up and down the east coast of Australia, primarily along the eastern coastal plain from Bundaberg in Queensland, through New South Wales and south to eastern Victoria.
Flying foxes are critical in ensuring ecosystem health and the long-term survival of our Eucalypt forests. They forage on the fruit of native forests and vines, as well as the nectar and pollen of native trees, particularly Eucalyptus, Melaleuca and Banksia species. As a consequence, flying foxes spread seed and pollen over long distances improving the health and diversity of native forests.
The grey-headed flying fox (pteropus poliocephalus) can be recognised by its rusty red coloured collar, grey head and hairy legs.
Flying foxes are intelligent, social animals that live in large colonies comprised of individuals and family groups. They roost in trees during the day and establish permanent and semi-permanent camps near food sources and for birthing.
Flying foxes use various calls as a form of communication, tending to make the most noise at dawn and dusk, when flying out to feed at night or returning to camp trees to sleep during the day. Noise increases dramatically when animals are disturbed. During the day, flying foxes are generally quiet as they are nocturnal animals.
Flying foxes are very clean animals that are constantly grooming and cleaning themselves. However, they also communicate by scent. Odours are used to identify camp trees, each other, and also to attract mates. Mothers are able to locate their pups in crèche trees by their scent and calls.
Threats to Grey-headed flying fox
The grey-headed flying fox is listed as 'vulnerable to extinction' under NSW and Australian legislation because of declining numbers.
The main threat to grey-headed flying foxes is habitat loss, and this is a key cause of their conflict with humans. Clearing and modifying native vegetation removes appropriate camp habitat and limits the availability of natural food sources, particularly winter feeding habitat. In NSW, less than 15 per cent of potentially suitable forest for the grey-headed flying fox occurs in conservation resources and only five per cent of roost sites are similarly reserved.
Grey-headed flying foxes are increasingly setting up camp near towns and people in search of food and shelter because of loss of their natural habitat and in response to local food availability. They forage opportunistically, often at distances up to 30km from camps and occasionally up to 60-70 km per night in response to patchy food resources.
Grey-headed flying foxes are very vulnerable to heat stress.
Heat stress affects flying foxes when temperatures reach 42°C or more. When ambient temperatures rise above 35°C, flying foxes tend to alter their behaviour to reduce exposure to heat. This may include clustering or clumping, panting, licking wrists and wing membranes, and descending to lower levels of vegetation or to the ground. Over the past two decades, tens of thousands of flying foxes have died during extreme heat events including approximately 600 in Campbelltown during January 2018.
Grey-headed flying foxes may once have numbered in the millions, but now their population is estimated to have declined by at least a third.
Reducing the impacts of flying-foxes
Deterring flying foxes
If you experience an individual or small group of flying foxes feeding at night in your fruiting or flowering trees and shrubs, including palm trees, this will be ongoing until the fruit is finished. If you do not want flying foxes feeding in your backyard, you can remove the fruit manually or properly net the tree to make access for the flying foxes difficult. Only use netting with holes smaller than you could fit your finger through to prevent the flying foxes getting tangled.
There are simple, non-harmful deterrents which may be of assistance at your property, such as:
- creating visual/sound/smell barriers with fencing or hedges using plants that do not produce edible fruit or nectar-exuding flowers
- placing predator decoys (eg, owls) on verandahs or in trees
- keeping food or habitat trees in your yard trimmed and pruned
- placing reflective or shiny deterrents (eg, cds or aluminium foil strips) in tree branches
- when landscaping, plant fruit or habitat trees away from the home, or don’t use these plants at all.
Residents are not allowed to conduct flying fox removal or dispersal activities, so these actions are only able to be used in locations prior to flying-fox camps establishing. If a camp has been established, residents are reminded that any activities that may result in the disturbance of a roosting flying-fox colony or individual flying-fox can result in prosecution under the NSW National Parks and Wildlife ACT 1974, the NSW Biodiversity Conservation Act 2016 and the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act).
What is that noise?
Flying foxes are noisiest when the flying foxes leave their camp early in the evening to feed and when they return in the early morning. They continue being noisy as they fly around trying to find a roost. During the day they can fight and bicker like children over a favoured spot, usually trying to find one as close as possible to water. Unfortunately, this is a daily event while the camp is active.
When flying foxes are stressed or frightened they make a lot more noise.
Colonies tend to be noisiest when they are disturbed by people and least noisy when left alone. If you plan on making some noise near a camp, such as mowing the lawn, you can expect the flying foxes to get rowdy for a while.
Try to be considerate if you are visiting an area with a flying fox camp - do not disturb the animals, and help keep noise to a minimum.
What is that smell?
Humans have different sensitivities to smells. Not all people will find the smell of a flying fox camp difficult to live with. This may explain why residents sometimes find it difficult to get others to understand how much impact the odour has on their daily life.
The main odour associated with flying foxes is the scent male flying foxes use to mark their territory and is strongest at the camp. It is not associated with the faeces dropped during flight or around the camp. The most important thing to note is that the odour is not a risk to human health.
Predicting relief from the smell
The smell is usually at its strongest during hot, humid and still or low-wind days. Good rain will wash away the smell for a period of time. The wind direction will often also determine when the odour will be at its most difficult. Residents may find it useful to follow the weather forecasts and relate them to the high-odour days. This will help to predict when there may be some relief.
Managing the smell within the home
Planting vegetation with fragrant flowers can assist with masking camp odour. Fragrant deodorisers can assist within the home and it helps to close all windows and doors. Obviously this can be a problem on hot days. Where possible, use air conditioning on a recirculate option (where the air is drawn from inside the home rather than outside) or use fans to circulate internal air.
Flying fox faeces
Flying foxes excrete either during flight or by turning heads-up and holding onto a branch by their thumbs. The flying fox digestive system is much faster than a human system (12 to 30 minutes between eating and excreting). They often don't physically chew and swallow their food – they crush it against the roof of their mouth and spit it out after swallowing the juice. This primarily liquid diet contributes to their quick digestive system.
Faecal drop increases under flying fox foraging routes, or when they are disturbed and airborne for longer periods of time. Lighting assists flying fox navigation and increases fly-over, so where possible, turn off outdoor lighting at night.
Drying your clothes outdoors
Residents will experience the greatest impact from faeces 'bombs' on washing as the flying foxes fly over when they are leaving their camp in the evening or arriving in the morning. It is useful to note the approximate times the flying foxes leave and return in relation to the sunrise and sunset, to gain some level of control to know when to ensure washing is brought in off the line. Some residents in other regions have constructed tarpaulin coverings over their clotheslines to protect their washing.
To remove flying fox faeces from washing, treat them like fruit stains. Soak the item as soon as possible (preferably while the stain is still wet) in a good stain remover. Unfortunately, some fruits with strong coloured flesh (eg, mulberries) may leave a permanent stain.
Cars and other painted or outdoor surfaces
Some residents have reported that flying fox faeces seem to strip paint from cars, houses and garden furniture. There is some information to suggest that this is more likely due to the faeces drying and peeling off a surface and, especially if the underlying paint is older, lifting off a patch of the surface paint with it. Flying fox droppings are less corrosive than bird droppings, and the best response is to remove the faeces as soon as possible with soapy water, as you would for bird droppings.
If your pool has a filter system installed already and you follow the correct maintenance for your pool, this will be adequate to keep it clean and you shouldn’t have to take any extra action specifically to address flying fox faeces. If you’re experiencing a large volume of faeces, a pool cover is an option, but in general, flying fox faeces are no different to bird droppings landing in your pool.
Read the below: Can I drink the water from my rainwater tank?
Can I get sick from flying foxes?
Human infections from viruses borne by flying foxes are very rare. There are no confirmed cases of anyone ever getting sick by touching flying fox faeces, urine or blood, but of course you should still wash your hands after touching anything like that.
- Do not attempt to touch or handle live or dead flying foxes.
- Only trained, vaccinated bat handlers should attempt to catch injured or sick bats.
- If you encounter a sick, injured or dead bat, contact the experts at WIRES on 1300 094 737.
- If you have been bitten or scratched by a bat, gently, but thoroughly, wash the wound immediately with soap and water for at least five minutes and consult a doctor as soon as possible.
There are two well-publicised viruses borne by flying foxes
|Australian Bat Lyssavirus
Australian Bat Lyssavirus is a virus that is similar to rabies.
The virus can only be transmitted through contact of mucous membranes (including the eye) or broken skin with the saliva or neural tissues of a bat.
To date, there have only been three confirmed cases of Australian Bat Lyssavirus in humans. These have all occurred in Queensland and were the result of direct flying fox bites or scratches during the handling of infected animals.
There are no obvious indicators that a flying fox is carrying the virus, therefore it is always best to assume that any flying fox could be infected.
Hendra virus is an influenza-like virus and infection in horses and humans, and is rare.
There is no evidence of bat to human, human to human, bat to dog or dog to human transmission of Hendra virus.
It is thought that horses may contract Hendra virus infection from eating food recently contaminated by flying fox urine, saliva or other body fluids. All seven confirmed cases of Hendra virus in humans have been caused by exposure to high levels of virus in body fluids from infected horses, and all occurred in Queensland.
In some communities there has been concerns regarding flying foxes exacerbating poor health conditions for people with compromised immune systems or chronic respiratory problems. This has not been reported in relation to other flying fox camps, and Southern NSW Local Health District advises that there has not been an increase in respiratory-related admissions. However, if you are experiencing any medical concerns, it is recommended that you visit your doctor.
What about my pets?
The disease risk to people, their pets and horses from the flying foxes is very small.
NSW Health reports that there is no evidence of dog to human transmission of Hendra virus. According to the Australian Animal Health Laboratory in Victoria, there have been no reports of illness in pets caused by eating deceased flying foxes. However, pets should be kept away from flying foxes, if possible, to reduce the likelihood of scratches or bites. If a pet becomes sick after contact with a flying fox, seek advice from a veterinarian.
While activities to disperse the colony may increase the opportunity for contact between bats and domestic animals, because displaced flying foxes may turn up in areas where they haven't been previously, the risks are still very small.
Horses may get the Hendra virus infection from eating food recently contaminated by flying fox urine, saliva or other body fluids.
But there is no evidence of human to human, bat to human, bat to dog, or dog to human transmission of Hendra virus. All confirmed human cases to date became infected following high level exposures to body fluids of an infected horse, such as doing autopsies on horses without wearing appropriate personal protective equipment, or being extensively sprayed with mucous from infected horses.
If you have horses, keeping them away from flying fox camps and vaccines are the best way to reduce the risk of infection. Vaccines are available from your vet.
Can I drink the water from my rainwater tank?
If there is public drinking water available, NSW Health recommends you use this for drinking and limit the use of water from your tank to gardening, toilet flushing and car washing. Faecal contamination in rainwater tanks from wildlife is a known risk not just associated with flying foxes, but also birds, possums, and other animals.
For households using rainwater for food preparation and drinking, the risk of getting a gastro illness from bat faeces is no different than for other animals. Australian Bat Lyssavirus cannot be contracted from drinking or using water from rainwater tanks that is contaminated with bat faeces.
To minimise the risk of faecal bacteria and other microorganisms contaminating your rainwater tank, here are some methods you can use:
- Install a ‘first flush’ device that will divert the first dirty water flow away from the tank.
- Clear and trim vegetation (eg, overhanging tree branches) away from awnings, gutters, and tanks to reduce accessibility from wildlife.
- Install a <1mm screen to filter material entering the tank.
- Regularly flush your tank to ‘de-sludge’ and remove accumulated debris.
- Disinfect your tank (eg, add 40ml of sodium hypochlorite per 1KL of water).
- Disinfect water prior to use through filtration and boiling.
- Regularly inspect the tank for signs of animal access.
It is the responsibility of the owner to ensure rainwater collected is treated to a healthy standard prior to consumption.
Legislation and approvals
Grey-headed flying foxes are protected under the NSW National Parks and Wildlife ACT 1974, are listed as vulnerable to extinction under the Biodiversity Conservation Act 2016 and the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act).
For further information you can read the:
The Department of Environment has released its referral guideline for management actions in grey-headed flying fox camps. This guideline provides greater certainty to proponents on whether or not they need to seek approval for management actions at camps.
In accordance with these NSW and Commonwealth legislation and guidelines, Council had to first apply for approval from both levels of government before taking any action that may harm or impact the species or their habitat.
Draft National Recovery Plan for grey-headed flying foxes
In January 2017, the Federal Department of Environment and Energy released the Draft National Recovery Plan and invited the public to comment.
The plan identifies recovery objectives and actions to improve the national population of the grey-headed flying fox by identifying and conserving critical foraging and roosting habitat and increasing awareness and understanding of flying foxes, their importance to our ecosystems and mitigating the threats they face.
The plan also sets out ways to improve the community’s capacity to coexist with flying foxes, while acknowledging the social and economic impacts and issues associated with urban camps.