Australian researchers buried discarded plastic pipes inside piles of mine waste rock; The cameras showed the northern quolls entering and exiting the artificial dens, in conditions similar to those in natural refuges.

What appears to be industrial waste could provide a small refuge for one of Australia’s most endangered marsupials. Researchers have begun converting discarded plastic pipes into artificial burrows at former mining sites in northwest Australia to offer northern quolls hidden refuges from harsh temperatures and humidity. According to a research study titled “Designing artificial dens for the Northern Quoll from readily available materials in the post-mining landscape,” the experimental approach could offer a simple and inexpensive tool for habitat restoration after mining, as well as a new use for material that might otherwise be abandoned.

A marsupial threatened by multiple dangers

For the uninitiated, northern quolls (Dasyurus hallucatus) are small carnivorous marsupials closely related to species such as the Tasmanian devil. They face a variety of threats and their numbers are plummeting across northern Australia. Invasive cane toads can poison quolls that try to eat them, while feral cats, habitat loss and intensifying fires put more pressure on them. Mining can make these problems worse by changing or destroying refuge and breeding areas.Rehabilitated mining sites can eventually provide habitat, but recreating natural refuges is not always easy. Artificial burrows must protect animals from extreme temperatures and humidity, but must also provide suitable conditions for rest and, perhaps, reproduction.

Turning mining waste into quoll sanctuaries

The researchers investigated whether high-density polyethylene (HDPE) pipes could be used in waste rock piles to create inexpensive artificial dens. The pipes were deep enough to provide a thermal buffer, essentially using the surrounding rock and soil to moderate internal conditions. The average maximum temperature in the artificial burrows during the demonstration test was around 33.6°C with a relatively low temperature range. The average maximum humidity was around 62%, which produced conditions similar to those found in the natural refuges of northern quolls.This approach can be particularly useful as HDPE pipes are widely available in many mines and rehabilitation projects can use existing materials rather than constructing purpose-built burrows.

Cameras filmed the quolls using the shelters.

The trial produced the most promising evidence from remote cameras and tracking platforms. Northern quolls were recorded entering and leaving buried pipes, suggesting that the animals were willing to investigate and use the artificial structures. But researchers say there is no firm evidence yet that the burrows have been taken over as permanent homes or successfully used for reproduction. This distinction is important because building a shelter for an animal is not the same as providing habitat that can support long-term population reproduction and recovery.

More tests are needed

The researchers emphasize that the demonstration is only a first step. More replicated experiments are needed to determine optimal pipe length, burial depth and location, and how dens should relate to vegetation, food sources, and other landscape features. Reproductive success is critical to the stability of the northern quoll population. Artificial dens alone do not restore a species threatened by predators, invasive species, fires, and habitat loss.But the experiment suggests a practical possibility: Post-mining landscapes could be designed not just to cover industrial scars, but to actively recreate the refuges and ecological features that wildlife need. A discarded pipe buried under a pile of mine tailings. It may not seem like much. For a northern quoll seeking shelter, it could be the start of a new home.Images courtesy: istock