In the heart of urban Sydney, a tenacious population of long-nosed bandicoots is writing its own story of survival.
Nestled on a headland within Sydney Harbour National Park, the small, isolated population of long-nosed bandicoots at North Head is a living testament to resilience. This group of marsupials has become an unintentional ark, separated from other populations by the tide of urban development. Scientists have been closely studying these creatures, uncovering a story of remarkable adaptability shadowed by persistent threats. Their research reveals not just the biology of a species, but a crucial case study in how native wildlife can persist in—or succumb to—increasingly human-dominated landscapes.
The long-nosed bandicoot (Perameles nasuta) is a medium-sized marsupial, typically dark greyish-brown above and creamy white below, with the pointed snout that gives it its name . Adults usually weigh between 850 and 1,100 grams, with males being noticeably larger than females 6 .
They are ground-dwelling, nocturnal, and solitary, spending their days sheltered in well-concealed nests made from shallow holes lined with leaves and grass .
The bandicoots at North Head are not a different species, but they represent an endangered population as declared by the New South Wales government . This designation highlights their precarious situation.
They are restricted to the North Head peninsula in the Manly Local Government Area, effectively cut off from other populations by the urban sprawl of Sydney 6 . This isolation makes them uniquely vulnerable.
Despite these challenges, or perhaps because of them, this population has been the focus of intensive ecological study. A landmark 22-month research project, along with subsequent studies, has provided a detailed picture of their lives under pressure 1 .
The North Head bandicoot population is officially declared endangered by the NSW Government, highlighting its vulnerability to extinction.
The North Head bandicoots have shown extraordinary flexibility in their habits, a key trait for survival in a modified environment.
Throughout the year, these bandicoots feed primarily on invertebrates. Beetles, insect larvae, and ants form the bulk of their diet, but they also consume other invertebrates, along with plant roots, fungi, and even some vertebrate material 1 .
This dietary flexibility allows them to take advantage of whatever food sources are available. Researchers have even found human-derived materials like birdseed, vegetable scraps, and unfortunately, plastic and twine in their stomachs, indicating their willingness to forage in human-adjacent areas 1 .
Faced with high mortality, this population has developed a impressive reproductive output:
This "live fast, reproduce often" strategy is a common response to high environmental pressure, helping to ensure that enough young survive to maintain the population despite significant losses 6 .
Research has revealed a distinct difference in how male and female bandicoots use their habitat. Males maintain significantly larger home ranges (averaging 4.4 hectares) compared to females (averaging 1.7 hectares) 1 6 . Furthermore, the largest home ranges for males coincide with the peak breeding season in late spring and early summer, suggesting they travel more extensively to seek mating opportunities 1 . This highlights how life history demands directly shape an animal's use of space.
To truly understand the pressures on this population, we can look at a crucial research effort that laid the groundwork for all subsequent conservation work.
A comprehensive study was initiated to investigate the population biology, habitat use, and diet of the long-nosed bandicoots at North Head 1 . Over 22 months, researchers employed several key techniques:
Comprehensive 22-month research project begins to investigate bandicoot population biology.
Researchers employ live-trapping, radio-tracking, and dietary analysis to gather detailed data.
Study quantifies major causes of mortality and identifies critical threats to population survival.
Research provides evidence-based guidance for conservation actions to protect the population.
The results were revealing. The study found that the bandicoots utilized all macrohabitats available—open grassed areas, heath, forest, swamp, and scrub—but showed a strong preference for using open grassy areas for foraging 1 . This need for a mosaic of habitats (dense cover for nesting by day, open areas for foraging by night) is a key consideration for their management.
Most critically, the research quantified the major causes of mortality, providing hard data to guide conservation action.
Considered a probable overestimate due to the ease of finding road-killed animals.
Considered a probable underestimate as predation events are hard to find without radio-collars.
Includes disease, natural causes, and other undetermined factors.
Data sourced from Scott et al. (1999) 1
Understanding the lives of these elusive, nocturnal animals requires a specific set of tools and methods. Here are some of the key items in a bandicoot researcher's kit:
Safe, humane capture of individuals for measurement, health assessment, and tagging.
Tracking daily movements, locating nest sites, and monitoring survival in near real-time.
Precisely mapping animal locations, home ranges, and habitat features.
Identifying food items to understand diet composition and seasonal changes.
Assessing genetic diversity, inbreeding risk, and population connectivity.
Monitoring behavior, population counts, and predator presence without disturbance.
The threats to the North Head bandicoots are severe and interconnected. Predation by introduced foxes and domestic cats, and vehicle collisions are the two biggest direct causes of death 1 . Their isolation leads to a risk of inbreeding depression, which can reduce genetic fitness over time . Furthermore, habitat loss and fragmentation from development or inappropriate land management, including fires that are too frequent, can destroy the dense undergrowth they need for shelter .
The story of the North Head bandicoots serves as a powerful reminder of the fragility of urban wildlife. They are a population living on the edge, showcasing incredible natural resilience while facing human-made threats. Their continued survival hinges on our commitment to active conservation—controlling foxes and cats, protecting and connecting their habitat, and managing the urban footprint. In the conical holes they leave across the North Head landscape, we see not just the search for food, but the mark of a tenacious struggle for existence.