Native mammals across northern Australia face a host of threats, including feral cats, fires that destroy shelter and food sources, and other introduced pests like foxes and cane toads.

The northern quoll is a native carnivorous marsupial which is now listed as endangered, due to a sharp decline in numbers since the spread of cane toads. Wildlife ecologist Jonathan Webb is investigating whether quolls can be trained to avoid eating toads, as part of a broader program of research.

Quolls readily attack toads but are poisoned by the toads’ toxin, and die after coming into contact with large toads. Since 2009 Dr Webb has been trialling whether adult quolls can be trained to avoid attacking cane toads, and whether this improves their survival rate.

Working with Territory Wildlife Park and Kakadu staff, the research team trained 50 captive-reared northern quolls by feeding small dead toads laced with a chemical that made them sick. These ‘toad-smart’ quolls later refused to attack live cane toads.

The quolls were then released back into suitable environments near the East Alligator Ranger Station. Twenty cage traps were placed along six trap lines (120 in total) in crevices, under overhangs, and near logs, where quolls live.

When a quoll was caught, it was weighed, given a health check, and identified according to its microchip number with a scanner. The animal was then released back into the wild with minimal stress.

The research team found that some toad smart quolls survived and had babies. Genetic analysis showed that two of these offspring also went on to have babies. Toad-trained quolls may be able to increase northern quoll populations in toad-infested areas, but only if other threats such as frequent fire and predation by animals like feral cats and dogs are addressed.

The latter part of Dr Webb’s research in Kakadu was supported by the Northern Australia Hub, and field work is now underway in the Kimberley. Cane toads are just now arriving in one of the last remaining stronghold populations of northern quolls in Western Australia.

This research will contribute to a better overall picture of mammals across northern Australia and how we can prevent further species decline. Earlier this year the research team provided samples from quolls in the East Alligator River region for another study investigating disease in mammals.

Dr Webb is a Senior Research Fellow at the University of Technology Sydney. Other funding partners are Australian Research Council, the Mazda Foundation, and National Geographic Conservation Trust.

For more information, contact Dr Jonathan Webb. Email jonathan.webb@uts.edu.au or phone 0435 960 687.