A Pale Field Rat caught on camera.
The recent good rains have resulted in a profusion of grass seeds, insects and left-over agricultural grain causing a boom of rats and mice. In addition to our suite of native rodents, there are also a handful of introduced rats and mice and it can be tricky to tell the difference.
I was recently visiting my friends, Diane Guthrie and Paul Stevens on their Land for Wildlife property in the Upper Lockyer. Like many Land for Wildlife members, they have been battling rats and mice over the past year and aim to keep the native ones while humanely disposing of the introduced Black Rat (Rattus rattus) and House Mouse (Mus musculus).
Around Paul’s shed and throughout the property, there are indicators of small animals busy at work. Tunnels are everywhere. There are tunnels under shrubs and Lantana. Tunnels through grass clumps and diggings abound. The tunnels are shallow and more horizontal than deep. Martin Bennett, Lockyer Valley Regional Council Land for Wildlife Officer has been seeing such tunnels on several properties lately. Martin is familiar with the maker of these tunnels as he has surveyed them extensively on the Darling Downs and has fallen into their shallow tunnels on many occasions.
The tunnels are created by the native Pale Field Rat (Rattus tunneyi). Most tunnels will have excavated soil at the entrance and can be up to 1.5m in length. The tunnels I saw at Diane and Paul’s place look more like half a metre long. These shallow tunnels have thin ceilings only a few centimetres thick and are probably deliberately thin so that if a predator was to enter, the Pale Field Rat could break through the ceiling and escape.
At a glance, the Pale Field Rat can look at bit like the introduced Black Rat, but there are differences to keep in mind, as shown in these photos.
Many of our small to medium-sized native mammals are diggers – think of the bilby as an example. Their excavations are incredibly important ecologically as they recycle nutrients, improve rainfall infiltration, create habitats for other wildlife and disperse seeds and fungal spores. As we know, Australia has a terrible reputation of leading the world in extinctions of small to medium-sized mammals since colonisation. The Pale Field Rat was once found across mainland Australia. Early European explorers cursed their dense tunnels as horses found it hard to keep their footings. It is estimated that Pale Field Rats now occupy only 10% of their former range, confined to coastal Top End and parts of coastal Queensland.
The Pale Field Rat probably moves more soil than any other native mammal in SEQ and, as such, should be revered. It is a legacy of a landscape that is hanging on.
So, I want to say thanks to Diane and Paul and all other Land for Wildlife members who have taken the time to carefully identify rodents before disposal. The fact that Pale Field Rats are still here today in SEQ, at the southern limit of their range, is a testament to their survival despite overwhelming odds. They provide us with a small insight as to what this country looked like under Indigenous management, before rabbits, cats, foxes, cattle, roads and land clearing.
If you catch a rodent and are unsure of its identification, please send a photo through to your Land for Wildlife Officer or the Queensland Museum before making an irreversible decision.
References and Further Reading
Braithwaite RW & Baverstock PR (1995) Pale Field-rat. The Mammals of Australia Revised Edition. Edited by R. Strahan. Reed New Holland.
Article and photos by Deborah Metters
Land for Wildlife Regional Coordinator
South East Queensland