Mulligans Flat

Mulligans Flat Woodland Sanctuary is the largest remaining area of critically endangered Yellow Box–Blakely's Red Gum Grassy Woodland in the Australian Capital Territory, protecting 9.84 square kilometres of internationally significant dry woodland habitat. Established in 1994 and located on Canberra's northern edge near Gungahlin, the reserve operates Australia's largest inner-urban predator-proof fenced sanctuary, covering approximately 486 hectares and surrounded by a 13-kilometre exclusion fence completed in 2009. Together with the adjoining Goorooyarroo Nature Reserve, Mulligans Flat forms an 18 square kilometre conservation estate that supports the reintroduction of species extinct from the ACT for over a century, including eastern bettongs, eastern quolls, and greater bilbies.

Within the predator-proof sanctuary, a growing population of eastern bettongs (Bettongia gaimardi) — extinct on mainland Australia for 80 years before their reintroduction here — forages through the woodland floor, dispersing fungal spores and turning over soil in ecologically significant ways. Eastern quolls, reintroduced in 2016 as a trial for mainland recovery, hunt invertebrates and small vertebrates through the understorey. Greater bilbies were also introduced as part of a recovery breeding program. Southern brown bandicoots and bush stone-curlews complete the ground-dwelling fauna community. Outside the fence, eastern grey kangaroos are abundant, and the reserve hosts 120 recorded bird species including superb parrots, diamond firetails, and the vulnerable swift parrot during migration seasons.

The dominant vegetation is Yellow Box (Eucalyptus melliodora) and Blakely's Red Gum (Eucalyptus blakelyi) grassy woodland — once widespread across the southern tablelands but now reduced to less than 5 percent of its original extent due to clearing for agriculture and urban development. The ground layer comprises a diverse suite of native grasses including kangaroo grass (Themeda triandra), wallaby grass, and weeping grass, interspersed with native forbs including bluebells, lilies, and native everlastings. The intact ground layer is critical to the reserve's ecological function, providing habitat for small mammals, invertebrates, and reptiles. Weed management is ongoing to control invasive grasses and herbs that threaten to displace native species.

Mulligans Flat sits on a broad, gently undulating plain underlain by Silurian-age granites and quartz monzonites that have weathered over millions of years to form deep, nutrient-poor soils. The landscape is characteristic of the Southern Tablelands — a peneplain surface eroded to low relief over geological time. Shallow rocky outcrops emerge at scattered locations, supporting patches of lithophytic mosses and specialist plant communities. The soils are predominantly red-brown earths and yellow-grey earths derived from granite parent material, with a natural tendency toward compaction that historically made them attractive for grazing. The reserve's topography is relatively flat, with a gentle slope toward drainage lines that collect water during rainfall events.

The reserve experiences a cool temperate continental climate, with hot, dry summers and cold winters. Summer daytime temperatures regularly exceed 30°C, with heatwaves occasionally reaching 40°C. Winters are cold, with overnight frosts occurring from May through September. Mean annual rainfall is approximately 600–650mm, with a slight summer maximum linked to convective thunderstorms. Seasonal drought stress can be significant during hot, dry summers, and the reserve's woodland species are well adapted to periodic moisture stress. Snow is rare at this elevation (approximately 620m) but occurs occasionally during winter cold fronts. The dry continental climate is reflected in the fire-adapted nature of the Yellow Box–Red Gum community.

The land within Mulligans Flat has been Ngunnawal country for tens of thousands of years. The open woodlands and grassy plains would have provided important resources including wallabies, bettongs, lizards, and plant foods such as yam daisies and native grains. European pastoral settlement began in the 1820s and 1830s, with sheep and cattle grazing progressively degrading the grassy woodland community through soil compaction, selective grazing of native plants, and the introduction of weeds. By the mid-twentieth century, the native ground layer had been largely replaced by introduced pasture species across much of the region. The progressive exclusion of livestock from the reserve since its establishment in 1994 has allowed significant recovery of native ground cover vegetation.

Mulligans Flat was gazetted as a nature reserve in 1994 to protect one of the ACT's most significant remnants of grassy woodland. In 2009, the 13-kilometre predator-proof fence was completed, enabling the reintroduction of locally extinct fauna. Eastern bettongs sourced from Tasmania — where a viable wild population persists — were the first species reintroduced, arriving in 2012. The sanctuary has since become a reference site for monitoring the ecological effects of bettong reintroduction, particularly their role in soil turnover and mycorrhizal fungal dispersal. The connected Goorooyarroo Nature Reserve to the north was incorporated into the broader management framework in 2011, significantly expanding the effective conservation area. The reserve is managed by the ACT Parks and Conservation Service in partnership with the Mulligans Flat Woodland Sanctuary community committee.

Mulligans Flat offers walking trails through the grassy woodland, with the primary trail network providing approximately 6–8 kilometres of formed tracks accessible to visitors. The sanctuary zone is entered through a series of double-gated airlocks that prevent escape of reintroduced species and entry of predators. Visitors can walk through the sanctuary during daylight hours and frequently observe eastern bettongs foraging, particularly in early morning and late afternoon. Guided nocturnal spotlight tours are offered periodically and provide the best chances of observing bettongs and other nocturnal wildlife. Wildlife hide structures at several locations allow quiet observation of bird and mammal activity. The visitor centre provides interpretive displays on the history and ecology of Yellow Box–Red Gum grassy woodland.

The Mulligans Flat Woodland Sanctuary Visitor Centre is located at the main entrance off Horse Park Drive, near Forde in Canberra's Gungahlin district. The reserve is accessible by private vehicle and is approximately 20 kilometres from central Canberra. Visitors enter through the main gate complex and must ensure all gates are securely closed at each airlock. Facilities include picnic areas, toilets, and interpretive signage. No entry fee applies for self-guided day visits. Guided tours and educational programs must be pre-booked through the visitor centre. Dogs and other pets are strictly prohibited to protect the reintroduced fauna. The sanctuary is open from dawn to dusk daily.

Mulligans Flat represents one of Australia's most important urban conservation experiments, demonstrating that fenced sanctuaries can successfully restore ecological communities within heavily modified landscapes. The eastern bettong population has grown substantially since reintroduction and is now contributing individuals to other reintroduction programs in the ACT and New South Wales. Research programs examining bettong-soil-fungal interactions have produced internationally significant findings on the role of small mammals in maintaining woodland ecosystem function. The reserve operates in close partnership with the Australian National University, Parks Australia, and conservation organisations including WWF-Australia. Ongoing weed control, fire management, and hydrological monitoring underpin the reserve's management. Community volunteer programs contribute significantly to restoration activities.