Perched on the northern side of Sydney Harbour, North Head is a 250–ha site of high ecological value. It supports critically endangered Eastern Suburbs Banksia Scrub and threatened Long-nosed Bandicoots, as well as successfully reintroduced populations of native Bush Rat, Brown Antechinus and Eastern Pygmy Possum.
AWC works in partnership with the Sydney Harbour Federation Trust to deliver a suite of science projects within North Head Sanctuary. The Sanctuary, comprising 74 hectares of land held by the Harbour Trust, is managed in an integrated manner with the adjoining Sydney Harbour National Park. Together, the sanctuary and the National Park protect most of North Head, representing one of the most important sites for biodiversity conservation within the Sydney Basin.
North Head is a sandstone headland on the northern side of Sydney Harbour, connected to the mainland only by a sand spit. It is an outlying remnant of the Hornsby Plateau, and supports a diverse range of habitats. North Head Sanctuary is located on the highest part of the peninsula and encompasses shrub, open banksia heath, forest/woodland and sections of littoral rainforest, fern and wetland vegetation communities.
North Head Sanctuary is located on Sydney Harbour Federation Trust (SHFT) land and was historically used by the Australian Defence Force prior to and during World War II, and the School of Artillery up until 1998, before it was opened to the public in 2007.
The dominant habitat of North Head Sanctuary is Eastern Suburbs Banksia Scrub. This endangered ecological community now covers less than three per cent of its original distribution, and North Head is home to half of all that remains. It contains a wide composition of flora species including Banksia and Xanthorrhoea species, Tea Tree (Melaleuca alternifolia), and small native forbs, grasses and shrubs. However, sections of the Banksia Scrub are deteriorating due to Tea Tree dominating and excluding the regeneration of other plants.
There is a network of hanging swamp wetlands in North Head, with pockets of heath, fern, shrubland and forest. Several rare and endangered flora species also persist here including Camfields Stringybark (Eucalyptus camfieldii), the Sunshine Wattle (sub-species Acacia terminalis ssp terminalis) and Hairy Geebung (Persoonia hirsuta).
The white quartz covered sand dunes at the centre of North Head are some of the last examples of undisturbed, vegetated, high-level sand dunes in the Sydney region. Characteristic of the Eastern Suburbs Banksia Scrub community, nutrient poor soils of Aeolian dune sands overlay the Hawkesbury Sandstone throughout much of North Head Sanctuary. The area has a temperate climate, and rainfall is spread throughout the year. Bushfire season runs from October to March.
Wildlife at North Head
Despite its proximity to Sydney, North Head is relatively isolated due to its geography and historical use. Along with active management, this has allowed a number of species to persist in the area, and the sanctuary is now home to a diverse array of flora and fauna. Notable species include an endangered population of the Long-nosed Bandicoot, as well as threatened species such as the Eastern Bentwing-Bat, Grey-headed Flying-fox, Powerful Owl and Barking Owl and the federally listed Large-eared Pied Bat.
Long-nosed Bandicoots were once widespread and common in Sydney, but are now restricted to a few populations, including a small isolated population (less than 170 individuals) on North Head. They are vulnerable to predation by cats and foxes, like many other mammals of their size. AWC is working to protect the North Head population, by monitoring numbers (in conjunction with NPWS), keeping track of threats, and researching vegetation restoration and its value for bandicoots.
However, like the rest of Australia, North Head has suffered local extinction of a suite of species since European settlement, most notably the Brown Antechinus (Antechinus stuartii), Eastern Pygmy Possum (Cercartetus nanus), Eastern Quoll (Dasyurus viverrinus), Spotted-tailed Quoll (Dasyurus maculatus), Swamp Wallaby (Wallabia bicolor) and Bush Rat (Rattus fuscipes). The reintroduction of locally extinct species and the resumption of the ecological processes in which these species participate (e.g., seed and spore dispersal, pollination, herbivory, predation) is an important component of the ecological restoration of North Head.
AWC Field Programs at North Head
AWC’s primary focus at North Head is the conservation of surviving native species, and the return of locally extinct species such as the native Bush Rat. This is achieved through a program of feral predator and herbivore control, fire and weed management. AWC also implements a range of science projects relevant to the restoration of the biodiversity of North Head.
The cats on North Head are predominantly domestic pets that make forays into bushland and attack local fauna. The density of foxes on North Head is relatively low, however foxes occasionally disperse to the headland where they can cause high mortality amongst native wildlife if not rapidly detected and eradicated. The small, isolated population of Long-nosed Bandicoots on North Head are particularly susceptible to foxes and cats. AWC is using a range of techniques to monitor North Head for incursions of feral predators, including spotlighting and infra-red cameras.
Weed control is implemented by SHFT and supported by the North Head Foundation.
Fire on North Head is jointly managed by SHFT, New South Wales National Parks and Wildlife Service (NPWS) and other government agencies. Fire management is not conducted by AWC, but AWC provide scientific support related to the role and impact of fire on the habitats of North Head, particularly the Eastern Suburbs Banksia Scrub.
In October 2020 a hazard reduction burn jumped containment lines and destroyed a substantial section of the AWC project area. AWC ecologists responded quickly by rescuing wildlife, creating shelters and assessing the impact to the headland. Wildlife and habitat recovery is ongoing. Prior to this, most of North Head had not been burnt for over 50 years.
Wildlife Reintroductions at North Head
Like much of Sydney, North Head has lost a suite of native mammals since European settlement. AWC is restoring the faunal diversity of North Head through a reintroduction program of locally extinct species. Since 2014, AWC has reintroduced three species:
Through the reintroduction of these three species, AWC has increased the native mammal assemblage on the headland from five to eight species. Prior to this work, no native mammals smaller than ~700 grams persisted. These reintroductions are helping to restore the ecological role of native small mammal species as pollinators on North Head, particularly in relation to Banksia species within the critically endangered ecological community Eastern Suburbs Banksia Scrub.
Science at North Head
AWC carries out monitoring and research to track the outcomes of reintroductions for the species and ecosystems of North Head. We measure the success of reintroductions and the establishment of sustainable populations, and determine how the reintroduced animals use the habitats.
We also look at interactions amongst reintroduced species, and their relationships with feral animals; for example, we have shown that native Bush Rats can defend territories from invasive black rats.
AWC is currently developing strategies to enhance the conservation value of the headland by sustaining reintroduced populations, and identifying a number of other mammals that could be reintroduced.
Following the 2020 fire at North Head, AWC developed post-fire management strategies to maximise the survival of persisting wildlife. In particular, artificial provisions (food, water, shelter) supplement what dense vegetation once provided, increasing chances of survival by maintaining provisions until burnt habitat regenerates and sufficient resources become available. Via camera monitoring, trapping and regular assessments, ecologists gather data on provision usage, activity and animal health to assess the utility and future viability of post-fire interventions:
Wildlife in the Sydney region is under threat from loss of habitat, changed fire regimes, and predation by cats and foxes. The cats on North Head are predominantly domestic pets that make forays into bushland and attack local fauna. The density of foxes on North Head is relatively low, however foxes occasionally disperse to the headland where they can cause high mortality amongst native wildlife if not rapidly detected and eradicated. AWC is using a range of techniques to monitor North Head for incursions of feral predators, including spotlighting and infra-red cameras. The habitats on North Head remain relatively intact, so the headland represents the ideal opportunity to preserve and restore a functioning ecosystem in the region by reintroducing several locally-extinct species.
Weighing less than a golf ball, the Eastern Pygmy Possum is one of the smallest possums in the world.
AWC helps protect a population of Brown Antechinus on North Head Sanctuary.