Joining forces: cultural knowledge and modern science combine to safeguard Kimberley bilbies Bilbies were once widespread across most of Australia. But, like so many other native Australian animals, they have fallen victim to introduced foxes and feral cats, and the impact of land clearing and altered fire regimes. Two projects underway in the Kimberley region – one on the Dampier Peninsula and the other in the Fitzroy River catchment – are providing opportunities for DBCA to work with Indigenous ranger groups to combine traditional cultural knowledge with contemporary science to improve the outlook for this iconic species. by Ruth McPhail, Bruce Greatwich, Fiona Carpenter and Martin Dziminski LANDSCOPE 23 estern Australia’s remote Kimberley region is about Wthree times the size of England and twice the size of Victoria. It is known for its rugged, beautiful scenery and rich and ancient cultural history. It is remote and sparsely populated, with only 0.09 people per square kilometre, compared to the average of 3.3 people per square kilometre nationwide, and provides a stronghold for many native species. Currently, about 93.5 per cent of the Kimberley region has been determined as native title. As majority landholders in the Kimberley, traditional owners and their ranger groups are responsible for the health of their country. This has provided agencies such as DBCA with the opportunity to work with Indigenous ranger groups to combine traditional cultural knowledge with contemporary science to work on country and conserve natural and cultural values, and protect species such as the greater bilby (Macrotis lagotis). Previous page Main The greater bilby is the only remaining BILBY BIO bilby species in Australia. Historically, there were two species Photo – Jiri Lochman of bilby – the lesser bilby (M. leucura) and Inset Research teams have been surveying the Kimberley to determine the range of the greater bilby (M. lagotis). The lesser bilbies. bilby became extinct in about the 1950s or 60s, and now only the greater bilby Above Typical bilby habitat of the northern survives. This species has achieved icon Great Sandy Desert. status among Australian marsupials, due Photos – Ruth McPhail/DBCA to its unique appearance, conservation Right An active bilby burrow in a termite significance and cultural importance to mound. traditional owners. Photo – Bruce Greatwich/DBCA Bilbies are nocturnal omnivores that do not need to drink water; they get all the moisture they need from their food, which includes arthropods and their larvae, seeds, bulbs, fruit and fungi. They Environment Protection and Biodiversity food, bilbies can turn over large amounts were once widespread across most of Conservation Act 1999 and the Western of soil, which aerates it and provides mainland Australia. However, due to Australian Biodiversity Conservation improved conditions for seed germination. the introduction of feral cats and foxes, Act 2016. Losing bilbies would irreparably change changed fire regimes, and the degradation Bilbies are known as ‘ecosystem the habitats in which they live, with of habitat, the bilby’s range and abundance engineers’, which mean they play an implications for the biodiversity of has decreased significantly. They have important role in their environment by these areas. disappeared from at least 80 per cent of significantly modifying habitat. They are Throughout most of their range, their former range across Australia, and active diggers, and build deep extensive bilbies occur in low densities, can show their numbers continue to decline. The burrows, that other native species, such low site fidelity and are thought to be species is currently listed as Vulnerable as small mammals, goannas, birds and highly mobile in response to resource under the Australian Government’s snakes, use for refuge. While foraging for availability and habitat modification. This 24 LANDSCOPE Distribution of bilbies Dampier Peninsula Fitzroy River catchment Bilbies Current distribution Historical distribution “... the bilby’s range and abundance has decreased Hear more about significantly; they have disappeared from at least 80 per cent bilbies of their former range across Australia.” Scan this QR code or visit Parks and Wildlife Service’s ‘LANDSCOPE’ playlist on YouTube. mobility and transient use of habitats of the bilby in a region of Australia where mean that individuals and colonies can be our knowledge is poor. The information Above The Dampier Peninsula is home to the most northern population of bilbies. difficult to locate and monitor over time. gathered will help inform management Photo – Ruth McPhail/DBCA While bilby populations in south-west actions at a larger scale. Queensland and the Tanami Desert in the Northern Territory have been better MONITORING THE BILBIES OF studied, their status in large parts of THE DAMPIER PENINSULA Western Australia remains unknown. The Dampier Peninsula in the far To determine occupancy and Until now, there have been few studies north-west Kimberley is known for its red distribution of bilbies, the Nyul Nyul, Bardi of the bilby’s distribution in the north of pindan cliffs and crystal blue ocean. Jawi Oorany, Nyikina Mangala Rangers Western Australia, especially in the It is also home to the most northerly bilby and Yawuru Country Managers have West Kimberley. populations in Australia. As part of the partnered with DBCA to survey bilby Recently, two projects have been Cape Leveque Road upgrade project, habitat using a standardised two-hectare established in the West Kimberley to Main Roads WA provided funding to sign plot technique, which has been conserve and protect bilbies – the Dampier offset impacts on local bilby populations. developed and successfully used in other Peninsula bilby project and the Fitzroy Coordinated by DBCA, this project parts of Australia. This technique consists River Catchment bilby project. These aims to improve our understanding of of a roughly 100 x 200-metre search area, projects aim to identify how many bilbies the distribution, habitat preferences and where evidence of bilbies is searched for live in these areas and the threats they threats to these populations and inform and recorded. Tracks and signs of other face. On-ground management activities, appropriate fire management across the animals, such as snakes, lizards and birds, such as prescribed burning, will also peninsula to ensure bilbies persist. As are also recorded, as well as information be implemented at key sites in trials to bilbies are nocturnal and cryptic, the about the habitat, and observations of manage and protect bilby habitat. best way to estimate their distribution is introduced predators (foxes and feral cats) These projects provide an important to search for signs, such as tracks, scats, and large herbivores (cattle, donkeys, opportunity to improve our knowledge diggings and burrows. camels and horses). For this project, the LANDSCOPE 25 Above Camels have been known to degrade and cause erosion to bilby habitat. Photo – Ann Storrie Above right Nyikina Mangala rangers Nathan Green and Shaquille Millindee entering data after completing a bilby plot. Photo – Bruce Greatwich/DBCA Right Bilby tracks and scats reveal clues about the species’ distribution. Photo – Ruth McPhail/DBCA impact of late dry season fire on bilby However, a novel technique developed moth larvae (witchetty grubs) – a major occupancy is being investigated. To date, by DBCA scientists, which uses DNA food resource for bilbies on the peninsula more than 250 two-hectare plots have extracted from bilby scats, is providing – can be found. Bilbies are also known to been completed. accurate information about the population eat yakirra (Yakirra australiensis) seeds and In the past, determining the size size. This technique enables researchers bush onion (Cyperus bulbosus) bulbs. They of a bilby population has been difficult. to distinguish individual bilbies from scat also dig for termites in the late dry season. Counting the number of burrows within samples, which they can use to calculate an area does not provide you with an an estimate of population size. FITZROY RIVER CATCHMENT accurate number of bilbies that live Active bilby sites have been found in BILBY PROJECT there, as individual bilbies can use up to areas where the substrate is suitable for Another recently commenced 18 burrows within their home range, and burrowing, and where the particular Acacia project – the Fitzroy River Catchment there may be disused burrows present. spp. and Senna spp. that bilbies use as cues bilby project – has already contributed They are also extremely hard to trap and for food sources occur. At sites where useful data about the distribution of mark, as they are ‘trap shy’ and don’t tend bilbies are found, these Acacia spp. typically bilbies in the area. It uses a combination to be lured by bait. form monospecific stands where cossid of Indigenous cultural knowledge, such 26 LANDSCOPE as expert tracking and local knowledge two-hectare sign plot technique to bilby will be protected long into the of bilby populations, and contemporary determine where bilbies live. Using a future. And, these projects have provided science to map the distribution of bilbies standardised technique is important, the invaluable opportunity to develop and help inform management actions, so that occupancy at other surveyed partnerships with traditional owner groups such as feral predator control, and fire and areas can be compared, and to highlight and other land managers. livestock