Bats

The forests, waterways and grasslands of the Park provide a haven for native bats. One species of megachiropteran bat and 9 species of microchiropteran bats have been recorded to date. All bat species are nocturnal - hunting by night and roosting by day.

Megachiropteran bats (megabats) are generally large bats, with wingspans of up to one metre. They eat nectar and fruit, and rely on acute night vision and a keen sense of smell to locate food trees. During the day, they roost in large numbers in tree branches, usually located in rainforest gullies or along rivers or creeks. The only megabat species to have been recorded at Sydney Olympic Park is the Grey-headed Flying-fox. It does not currently roost at the Park, but can often be seen and heard at night, flying overhead and feeding on flowering and fruiting trees.

Microchiropteran bats (microbats) are mostly insectivorous species that navigate and hunt their prey using echolocation. Most species are small, averaging 9cm in body length and weighing less than 13g, with a wingspan of less than 25cm. By day, they normally roost within the hollows of live or dead trees, under bark, or within caves. Within urbanised areas where natural habitat is less available, many bats roost within the roof or wall cavities of buildings, stormwater drains and other man-made structures. During the breeding season, females may congregate in ‘maternity roosts’ for several months until their young become independent.

Nine microbat species have been recorded at Sydney Olympic Park in recent years:

1. White-striped Free-tailed Bat - Tadarida australis
2. Lesser Long-eared Bat - Nyctophilus geoffroyi
3. Gould’s Wattled Bat - Chalinolobus gouldii
4. Chocolate Wattled Bat - Chalinolobus morio
5. Eastern Free-tailed Bat - Mormopterus ridei
6. Eastern Bent-winged Bat - Miniopterus orianae oceanensis
7. Little Bent-winged bat - Miniopterus australis
8. Large Forest Bat - Vespadelus darlingtoni
9. Eastern Broad-nosed Bat - Scotorepens orion

Microbats have been recorded across all built and parkland areas of Sydney Olympic Park, however their main feeding, roosting and breeding habitats appear to be in remnant  forest at Newington Nature Reserve and Newington Armory. The White-striped Free-tailed Bat, Lesser Long-eared Bat and Gould’s Wattled Bat use the roof and wall cavities of some of the heritage buildings in the Armory as maternity roosts.

Conservation significance

Some bat species have adapted well to urban environments, but many microbat species are in decline around Sydney. Sydney Olympic Park is rich in species diversity – it is still inhabited by 9 of the 17 bat species thought to have inhabited the area at the time of first European settlement.

Two of the microbat species that currently occur at the Park, the Eastern Bent-winged Bat and the Little Bent-winged Bat, are listed as vulnerable species under the NSW Threatened Species Conservation Act 1995.

The White-striped Free-tailed Bat maternity roost at Newington Armory is of high conservation significance as it is the only one known to occur in the Sydney region. It is therefore likely to be important to the conservation of the regional population of this species. It is also the only known White-striped Free-tailed Bat maternity roost that occurs within a building (maternity roosts of this species are usually within tree hollows).

Management

Management actions to promote bat species diversity and abundance include:

• strategic planting of shrubs to increase the extent and diversity of microbat foraging habitat
• minimising or avoiding disturbance from noise and light in key microbat habitat areas.
• restriction of access to buildings known to be used by bats to protect roost sites
• retention of dead trees in forests to provide roosting habitat
• installation of bat roost boxes to provide additional roost sites
• monitoring of Microbat populations to guide ongoing habitat management.