FEATURE Ku-ring-gai Flying-fox Reserve Habitat restoration project, 15 years on By Nancy Pallin colony of Grey-headed Flying-foxes conflict between people and bats. As it Strong community support A(Pteropus poliocephalus) roosts in urban takes decades for trees to grow to a size led to government protection bushland in the northern Sydney suburb of capable of withstanding flying-foxes roost- Gordon (13.5 km north of the central busi- ing in their canopy, immediate intervention of a bat colony in northern ness district). Environment groups became appeared to be the best course of action. aware of its location following a survey of Sydney in 1985. Restoration bushland in the Ku-ring-gai Local Govern- Flying-foxes at Gordon ment Area (Buchanan 1983). Part of the land of the roosting habitat of the occupied by the flying-foxes was privately Flying-foxes were seen to rise out of the owned and a proposal to develop this for valley east of Gordon in the 1940s (H. Grey-headed Flying-fox housing led to strong lobbying by the com- George, pers. comm., 1983). From 1963, the munity for protection of the bat colony. (Pteropus poliocephalus) gardener of a neighbouring property, Lady The NSW Government and Ku-ring-gai Gowrie Nursing Home, noticed flying-foxes was implemented by a non- Municipal Council jointly purchased the camped each summer along Stoney Creek private land in 1985.This land was amalga- and on the steep, north-facing slope in what government organization in mated with Council-owned bushland and is now the western section of the Reserve. named Ku-ring-gai Flying-fox Reserve Breeding was observed and the colony num- cooperation with the local (14.6 ha) in 1991. bered approximately 2000 in 1973 (Robin- The Ku-ring-gai Bat Colony Committee, son 1973).The colony occupied between 1 government. The aims, now the Ku-ring-gai Bat Conservation and 2 ha and began occupying the site Society Inc. (KBCS), formed in 1985, recog- throughout the year (Puddicombe 1981). methods, results and nized a longer term threat to the flying-fox Regular counts during the nightly exodus colony. Serious die-back of the canopy trees challenges of the project so from the valley, from March 1985 to June used by the roosting flying-foxes was occur- 1990, fluctuated from a few hundred to one far are outlined. ring and severe weed infestation of the peak of 80 000 in February 1987 (Parry- understorey was preventing regeneration of Jones 1993). Counts between December new trees. A site assessment commissioned 1994 and November 1997 again showed by KBCS stated: ‘The native vegetation is fluctuations between zero and 59 000 dying and will be replaced within the next (D. Ford & M. Augee, pers. comm., 1998). 15–30 years by a tall shrub layer consisting Monthly counts from July 1998 to June 1999 of Lantana (Lantana camara), Small-leaved recorded a winter population of 13 000, Privet (Ligustrum sinense), Large-leaved rising to 45 000 in summer (M. Beck, pers. Privet (Ligustrum lucidum) and one native comm., 1999). species, Pittosporum (Pittosporum undula- The colony has occupied an area of tum). Morning Glory (Ipomoea indica) and 2–3 ha, with variations according to fluctua- ‘Trad’ (Wandering Jew; Trad fluminensis) tions in the numbers in residence at any will also remain very common. The trees, particular time. Since the early 1980s there Blackbutt (Eucalyptus pilularis), Turpen- has been a gradual shift eastward of the tine (Syncarpia glomulifera), Sydney Red colony from the western end of the Reserve Nancy Pallin is a founding member of the Ku-ring- Gum (Angophora costata) and Red to the present position in the central gai Bat Conservation Society Inc, PO Box 607, Mahogany (Eucalyptus resinifera) will no section (Fig. 1), and it appears that the Gordon NSW 2072, Australia. This article is based longer be present (Buchanan 1985)’. flying-foxes prefer to camp on slopes with a on her experience coordinating the Habit Restora- Loss of this habitat could result in flying- northerly aspect, especially in winter. Infor- tion Project and the volunteer bush regeneration foxes moving to an unknown, next-best site mation gathered by KBCS on other flying- team at Flying-fox Reserve over the last 15 years. in the Sydney area with the potential for fox colonies at Wingham Brush, Bellingen 10 ECOLOGICAL MANAGEMENT & RESTORATION VOL 1 NO 1 APRIL 2000 FEATURE They began the seemingly impossible task of implementing a weed control strategy based on releasing all areas with natural regeneration capacity from suppression by weed (Buchanan 1985;Wright 1991). Phase 1: 1987–90 The work of the volunteer team was later supplemented by a contract team, whose employment was made possible by a series of grants gained by the KBCS from the NSW Department of Environment and Planning. These grants were matched dollar for dollar by the Ku-ring-gai Municipal Council. The contract team worked in separate areas from the volunteers using the same tech- niques (Buchanan 1990). In the first year, a three-person contract team worked 5 days per week for 3 months to undertake addi- tional weed control works on steeper slopes. Subsequently, this work was ex- tended over the year, by contractors working 1 day per week for approximately 40 weeks. This enabled time for regenera- tion to occur and follow-up weeding to be carried out regularly over all areas. Figure 1. Three ‘snapshots’ showing the progressive movement of the flying-fox colony over time. Records are available from 1972. Phase 2: 1992–97 By 1990,the flying-fox camp had moved east- Island, Susan Island, Maclean, Booyong, Jam- winds, a local resident had observed bats on wards in the valley.This, and a NSW Restora- beroo and Indooroopilly Island confirmed the ground and clinging to rock faces where tion and Rehabilitation Trust Grant, allowed that they occupy different parts of the avail- seepages occurred. the contract team to undertake restoration able habitat over time.While the reasons for of the very degraded western section that such shifts are not known, such movements Aims of the project was previously inhabited by the bats. would allow recovery of the tree canopy, given that defoliation of branches occurs at The primary aim of the habitat restoration Phase 3: 1998–2000 regularly used roosts. project was to provide self-perpetuating A Natural Heritage Trust (Commonwealth Flying-fox colonies occur in many differ- indigenous roosting habitat for the colony Government) grant enabled contract bush ent vegetation types including rainforest, of Grey-headed Flying-foxes. A secondary regenerators to be employed to establish casuarinas, mangroves and in native and aim was to retain the diversity of native canopy seedlings in a 0.25-ha area within exotic trees in the Botanic Gardens in fauna and flora within the Reserve.A further the colony site. This area had only a few Sydney and Melbourne.This would suggest issue was that the regenerated vegetation Turpentines and Blackbutts left for roosting. that the structure of the vegetation is more should be compatible with native bushland Regenerators were also able to prevent important than species of tree.The Gordon in northern Sydney. further degradation of moderately weed- bat colony site assessment identified that infested bushland on the northern and flying-foxes use vegetation consisting of Habitat restoration start southern upper slopes by comprehensive four layers (Buchanan 1985).They used the weed control undertaken outside the tallest trees, Blackbutts and angophoras, to Habitat restoration work focused on bush- colony area. warm themselves on cool early mornings land weed control, initially undertaken by a and to cool themselves in summer breezes. small group of volunteers. Four hours per The most commonly used layer was the week,four to 10 ‘friends of bats’,some expe- A mosaic of treatments (somewhat lower) Turpentine canopy, with rienced in techniques of bush regeneration The reserve contains a mosaic of habitats taller shrubs used in high temperatures or practised in other parts of Sydney, girded ranging from rainforest in the riparian zones on cold, windy days. In extreme heat their loins with the uniform tool pouch, and lower slopes and sclerophyll habitats on (greater than 40°C) with dry westerly loppers and herbicide bottle (glyphosate). upper slopes. This means that a range of ECOLOGICAL MANAGEMENT & RESTORATION VOL 1 NO 1 APRIL 2000 11 FEATURE Grey-headed Flying-fox (Pteropus poliocephalus) and Ku-ring-gai Flying-fox Reserve A Grey-headed Flying-fox licking nectar and pollen from a Turpentine flower (photo: D. Williams). In 1984, NSW National Parks and Wildlife Service (NPWS) identified the bat colony as ‘the largest and most important mater- nity colony of the Grey-headed fruit bat known in the southern half of New South Wales. As such, it is probably crucial to the future survival of this species in the southern half of the State (McWilliam 1984)’. Since then, radio-telemetry research on the Grey-headed Flying-fox has provided new perspectives on the nomadic foraging behaviour of the species. Colony sites, such as the one at Gordon, are viewed as essential links in a chain of sites which are used permanently, annually or occasionally accord- ing to the availability of food resources (Eby 1995). These social mammals roost in trees by day. Colonies vary considerably in size from hundreds to many thousands, fluctuating according to variations in food resources (Parry-Jones & Augee 1991; Tide- mann 1995; Eby 1996; Stockard 1996). Their diet in Australia contains more than 100 species of native trees found in subtropical rainforests, eucalypt forests and woodlands, melaleuca swamps and banksia heaths (Parry-Jones & Augee 1991; Eby 1996).