Not in my backyard? How to live alongside flying-foxes in urban Australia

Not in my backyard? How to live alongside flying-foxes in urban Australia
Jonathan ChancellorMay 26, 2016

The Conversation

GUEST OBSERVER

The conflict between urbanites and wildlife recently developed a new battleground: the small coastal New South Wales town of Batemans Bay, where the exceptional flowering of spotted gums has attracted a huge influx of grey-headed flying-foxes from across Australia’s southeast.

In response to intense and highly publicised community concern, federal Environment Minister Greg Hunt has announced he will seek an immediate National Interest Exemption to facilitate dispersal of these bats – a move that risks undermining legal protections afforded to this and other threatened species.

Similar conflicts are occurring elsewhere in NSW, such as the Hunter region, where some unscrupulous members of the public lit a fire in a flying-fox roost at Cessnock.

With the ongoing expansion of the human urban footprint, animals are increasingly confronted with urban environments. Human encroachment into natural habitats generally negatively affects biodiversity. However, urban landscapes can present wildlife with an irresistible lure of reliable food supplies and other resources. While urban wildlife can provide a range of benefits to health and wellbeing, it can also be cause for frustration and conflict.

Urban human-wildlife conflict is a growing area of management concern and scientific research. But the research suggests that the current strategies for addressing NSW’s conflicts between humans and flying-foxes might not have the intended results.

Ruling the urban roost

Australian flying-foxes are becoming more urbanised, and the noise, smell and droppings from their roosts can have huge impacts on local residents.

A fundamental problem underlying current approaches to urban roosts is a lack of understanding of the extraordinary mobility of flying-foxes. They are some of the most mobile animals in Australia, with movements that range from foraging trips of up to 120 km in a single night to long-distance nomadism covering thousands of kilometres in a single year.

While roosts can remain active for decades, they are more like backpacker hostels than stable households, housing a constantly changing clientele that comes to visit local attractions. Roosts are connected into large networks through which flying-foxes move in response to changes in local food resources.

This explains the sudden influx in places such as Batemans Bay where preferred food suddenly becomes abundant. But it also highlights the importance of a national approach to flying-fox management and conservation.

Intense local flowerings of Eucalypts, such as spotted gums, produce copious amounts of nectar and pollen, which attract large numbers of flying-foxes and other species for several weeks. When a relatively small local flying-fox population that is tolerated by its human neighbours suddenly increases tenfold, it can place severe pressure on the local community.

Despite their transient nature, these influxes are often wrongly interpreted as population explosions, leading to calls for culling. In comparison, more humane tactics – such as using loud noise or vegetation removal to disperse the flying-foxes – can seem like a more balanced response. But does dispersal actually work?

Shifting the problem elsewhere

There is now ample evidence to show that dispersals are extremely costly and can exacerbate the very human-wildlife conflict that they aim to resolve.

Most dispersals result in the flying-foxes returning the original roost as soon as the dispersal program ends, because naïve new individuals continue to arrive from elsewhere. Overcoming this can take months or years of repeated daily dispersal.

Other dispersals result in flying-foxes establishing new roosts a few hundred metres away, typically within the same urban environment in locations that we cannot control. This risks shifting the problem to previously unaffected members of a community and to other communities nearby. 

While flying-foxes are often portrayed as noisy pests, they serve our economic interest by providing irreplaceable pollination and seed-dispersal services for free. What’s more, those same bats that annoy people during the day work tirelessly at night to maintain the health of our fragmented forests and natural ecosystems.

So it is in our national interest to manage conflict at urban roosts, by using approaches that balance community concerns with environmental consideration.

To be considered “successful”, a dispersal should permanently reduce conflict to a level that is acceptable to the community without causing significant harm to the animals. However, dispersals are currently implemented at the local council level with little or no monitoring of the impacts in or outside the immediately affected area. This makes it hard to assess whether they have been successful.

For example, it is not uncommon for flowering to cease and flying-fox numbers to decline naturally during the period of active dispersal. This gives the community a false sense that a permanent solution has been achieved, when in fact the issues will recur the next time the trees blossom. There is thus an urgent need for urban roosts to be managed with properly defined and applied criteria for success.

Evidence-based management

Unfortunately, lack of research effort directed at “ugly” and “less popular” Australian animals means that very few evidence-based management tools are available to deal with contentious roosts.

Research targeting a few key areas would greatly help efforts to improve urban roost management. For instance, we do not know how flying-foxes choose their roost sites, which leaves us unable to design “carrot solutions” by creating more attractive roost sites elsewhere.

Intensive tree-flowering events are relatively infrequent and hard to predict. This means that it is difficult to prepare communities for a sudden influx of flying-foxes.

Furthermore, the acceptability of various flying-fox management options differs between sections of the community, so it is difficult to find optimal solutions. Social scientists are currently trying to help identify priority areas that promote long-term viability of flying-foxes while also easing conflict with humans.

Local, state and federal governments continue to allocate considerable funds for dispersal responses, even though such actions are high-risk activities for local communities and are unlikely to provide long-term solutions. We argue strongly that targeted research is needed to better inform land managers and affected communities of flying-fox ecology and provide them with low-cost, low-risk, evidence-based tools for dealing with urban roosts.

Flying-foxes don’t care about legislative borders, and state-based responsibility for wildlife management leads to discontinuity in approaches between jurisdictions. While flying-foxes are being monitored at the national scale, this initiative needs to be combined with a uniform federal approach for managing flying-foxes in our human landscapes. Otherwise, conflicts such as those faced by the residents of Batemans Bay will continue unabated.

Justin Welbergen is senior lecturer in Animal Ecology, Western Sydney University and can be contacted here.

Peggy Eby is adjunct senior lecturer, Centre for Ecosystem Science, UNSW Australia and can be contacted here.

Both are authors for The Conversation.

Jonathan Chancellor

Jonathan Chancellor is one of Australia's most respected property journalists, having been at the top of the game since the early 1980s. Jonathan co-founded the property industry website Property Observer and has written for national and international publications.

Editor's Picks

Spyre Group brings successful Queensland blueprint to Melbourne with Hampton Ltd
Saxon Street by Milieu to bring new housing and urban design to Brunswick’s cultural core
Construction begins at Fishermans Bend Innovation Precinct
Gurner reveals new plans for final Jam Factory stage
Tian An launches North Village, Auburn Square second stage

Related Projects

16-22 Maud Street, Newstead QLD 4006
16-22 Maud Street, Newstead QLD 4006
16-22 Maud Street, Newstead QLD 4006
Price
Contact agent
35-37 Mount Street, Prahran VIC 3181
35-37 Mount Street, Prahran VIC 3181
35-37 Mount Street, Prahran VIC 3181
Price
Contact agent
118-124 Benelong Road, Cremorne NSW 2090
118-124 Benelong Road, Cremorne NSW 2090
118-124 Benelong Road, Cremorne NSW 2090
Price
Contact agent
118-120 Matthew Flinders Drive, Cooee Bay QLD 4703
118-120 Matthew Flinders Drive, Cooee Bay QLD 4703
118-120 Matthew Flinders Drive, Cooee Bay QLD 4703
Price
Contact agent
26-62 Kinross Road, Thornlands QLD 4164
26-62 Kinross Road, Thornlands QLD 4164
26-62 Kinross Road, Thornlands QLD 4164
Price
Contact agent
9-11 Baroonba Street, Whitebridge NSW 2290
9-11 Baroonba Street, Whitebridge NSW 2290
9-11 Baroonba Street, Whitebridge NSW 2290
Price
Contact agent
18 Ransley Street, Penrith NSW 2750
Perle, East Side Quarter, Penrith - 18 Ransley Street, Penrith
18 Ransley Street, Penrith NSW 2750
Price
Contact agent
Ernest Cavanagh Street, Gungahlin ACT 2912
Raya, Gungahlin - Ernest Cavanagh Street, Gungahlin
Ernest Cavanagh Street, Gungahlin ACT 2912
Price
Contact agent
39 Browning Street, South Brisbane QLD 4101
39-41 Browning Street, South Brisbane - 39 Browning Street, South Brisbane
39 Browning Street, South Brisbane QLD 4101
Price
Contact agent
675 Gardeners Road, Mascot NSW 2020
Kiara North, Mascot - 675 Gardeners Road, Mascot
675 Gardeners Road, Mascot NSW 2020
Price
Contact agent
187 Salvado Road, Jolimont WA 6014
Jolie, Jolimont - 187 Salvado Road, Jolimont
187 Salvado Road, Jolimont WA 6014
Price
Contact agent
47 Maning Avenue, Sandy Bay TAS 7005
Grace Residences - 47 Maning Avenue, Sandy Bay
47 Maning Avenue, Sandy Bay TAS 7005
Price
Contact agent
Cove Lane, Narooma NSW 2546
Cove, Narooma - Cove Lane, Narooma
Cove Lane, Narooma NSW 2546
Price
Contact agent
52-56 Ramsay Street, Five Dock NSW 2046
Ava, Five Dock - 52-56 Ramsay Street, Five Dock
52-56 Ramsay Street, Five Dock NSW 2046
Price
Contact agent
2375 Gold Coast Highway, Mermaid Beach QLD 4218
The Alfred - 2375 Gold Coast Highway, Mermaid Beach
2375 Gold Coast Highway, Mermaid Beach QLD 4218
Price
Contact agent
129-131 Russell Ave, Dolls Point NSW 2219
ALLURE COLLECTION - 129-131 Russell Ave, Dolls Point
129-131 Russell Ave, Dolls Point NSW 2219
Price
Contact agent
62 Constitution Avenue, Parkes ACT 2600
The Eastbourne on Commonwealth Park - 62 Constitution Avenue, Parkes
62 Constitution Avenue, Parkes ACT 2600
Price
Contact agent
155 Old Burleigh Road, Broadbeach QLD 4218
Sandpiper, Broadbeach - 155 Old Burleigh Road, Broadbeach
155 Old Burleigh Road, Broadbeach QLD 4218
Price
Contact agent
33 Vulture Street, West End QLD 4101
33 Vulture Street, West End QLD 4101
33 Vulture Street, West End QLD 4101
Price
Contact agent
19 Governor Terrace, Murarrie QLD 4172
Park Hill Village Collection, Murarrie - 19 Governor Terrace, Murarrie
19 Governor Terrace, Murarrie QLD 4172
Price
Contact agent
122 Marine Parade, Miami QLD 4220
Nalu, Miami - 122 Marine Parade, Miami
122 Marine Parade, Miami QLD 4220
Price
Contact agent
34 Jacaranda Place, Indooroopilly QLD 4068
34 Jacaranda Place, Indooroopilly QLD 4068
34 Jacaranda Place, Indooroopilly QLD 4068
Price
Contact agent
167 Old Burleigh Road, Broadbeach QLD 4218
167 Old Burleigh Road, Broadbeach QLD 4218
167 Old Burleigh Road, Broadbeach QLD 4218
Price
Contact agent
21 Queens Way, Yeerongpilly QLD 4105
Yeerongpilly Green - 21 Queens Way, Yeerongpilly
21 Queens Way, Yeerongpilly QLD 4105
Price
Contact agent
445-449 River St, Ballina NSW 2478
Solhaven - 445-449 River St, Ballina
445-449 River St, Ballina NSW 2478
Price
Contact agent
52 Sunset Boulevard, Surfers Paradise QLD 4217
52 Sunset Boulevard, Surfers Paradise QLD 4217
52 Sunset Boulevard, Surfers Paradise QLD 4217
Price
Contact agent
6 Jack Brabham Drive, Hurstville NSW
Horizon Hurstville - 6 Jack Brabham Drive, Hurstville
6 Jack Brabham Drive, Hurstville NSW
Price
Contact agent
49 Seena Drive, Edgeworth NSW 2285
49 Seena Drive, Edgeworth NSW 2285
49 Seena Drive, Edgeworth NSW 2285
Price
Contact agent
Lot 118 Ocean Steamers Road, Port Adelaide SA 5015
Lot 118 Ocean Steamers Road, Port Adelaide SA 5015
Lot 118 Ocean Steamers Road, Port Adelaide SA 5015
Price
Contact agent
203 Ashmore Road, Benowa QLD 4217
203 Ashmore Road, Benowa QLD 4217
203 Ashmore Road, Benowa QLD 4217
Price
Contact agent
41 Warrs Road & 7 Horizon Drive, Maribyrnong VIC 3032
41 Warrs Road & 7 Horizon Drive, Maribyrnong VIC 3032
41 Warrs Road & 7 Horizon Drive, Maribyrnong VIC 3032
Price
Contact agent
774 Ripley Road, Ripley QLD 4306
774 Ripley Road, Ripley QLD 4306
774 Ripley Road, Ripley QLD 4306
Price
Contact agent
6 Homelea Court, Rivervale WA 6103
6 Homelea Court, Rivervale WA 6103
6 Homelea Court, Rivervale WA 6103
Price
Contact agent
7002 Ripley Road, Ripley QLD 4306
7002 Ripley Road, Ripley QLD 4306
7002 Ripley Road, Ripley QLD 4306
Price
Contact agent
136-148 Fox Valley Road, Wahroonga NSW 2076
136-148 Fox Valley Road, Wahroonga NSW 2076
136-148 Fox Valley Road, Wahroonga NSW 2076
Price
Contact agent
3 Delos Way, Sorrento WA 6020
3 Delos Way, Sorrento WA 6020
3 Delos Way, Sorrento WA 6020
Price
Contact agent
77 Sutton Street, Redcliffe QLD 4020
77 Sutton Street, Redcliffe QLD 4020
77 Sutton Street, Redcliffe QLD 4020
Price
Contact agent
119 Queen Street & 86 King Street, Bendigo VIC 3550
119 Queen Street & 86 King Street, Bendigo VIC 3550
119 Queen Street & 86 King Street, Bendigo VIC 3550
Price
Contact agent
181 Prospect Road, Prospect SA 5082
181 Prospect Road, Prospect SA 5082
181 Prospect Road, Prospect SA 5082
Price
Contact agent
593-595 Albany Highway, Victoria Park WA 6100
593-595 Albany Highway, Victoria Park WA 6100
593-595 Albany Highway, Victoria Park WA 6100
Price
Contact agent
1-28, 40 Civic Way, Rouse Hill NSW 2155
1-28, 40 Civic Way, Rouse Hill NSW 2155
1-28, 40 Civic Way, Rouse Hill NSW 2155
Price
Contact agent
93-97 Bay Street, Brighton VIC 3186
93-97 Bay Street, Brighton VIC 3186
93-97 Bay Street, Brighton VIC 3186
Price
Contact agent
22-38 & 27-31 The Avenue, Coburg VIC 3058
22-38 & 27-31 The Avenue, Coburg VIC 3058
22-38 & 27-31 The Avenue, Coburg VIC 3058
Price
Contact agent
1F Ashline Street, Wollert VIC 3750
1F Ashline Street, Wollert VIC 3750
1F Ashline Street, Wollert VIC 3750
Price
Contact agent
Lots 100 & 900 Kentucky Court, Cockburn Central WA 6164
Lots 100 & 900 Kentucky Court, Cockburn Central WA 6164
Lots 100 & 900 Kentucky Court, Cockburn Central WA 6164
Price
Contact agent
1260-1272 Malvern Road, Malvern VIC 3144
1260-1272 Malvern Road, Malvern VIC 3144
1260-1272 Malvern Road, Malvern VIC 3144
Price
Contact agent
472 Regency Road, Prospect SA 5082
472 Regency Road, Prospect SA 5082
472 Regency Road, Prospect SA 5082
Price
Contact agent
273A Gorge Road, Paradise SA 5075
273 Gorge Road, Paradise SA 5075 - 273A Gorge Road, Paradise
273A Gorge Road, Paradise SA 5075
Price
Contact agent
426-440 New South Head Road, Double Bay NSW 2028
426-440 New South Head Road, Double Bay NSW 2028
426-440 New South Head Road, Double Bay NSW 2028
Price
Contact agent
270 The Esplanade, Miami QLD 4220
270 The Esplanade, Miami QLD 4220
270 The Esplanade, Miami QLD 4220
Price
Contact agent