Having recently worked in western Queensland, I can fully appreciate the far-reaching impacts of two generous wet seasons in a row… the landscape is truly rejoicing.
Sweeping flourishes of green from renewed growth, splashes of brown, yellow and red where flood waters have washed away the dust and revealed new, fresh earth – and potholes the size of 44 gallon drums! And, of course, the wildlife has gone nuts!
Plains are dotted with fat kangaroos and emu chicks, skies are crowded with soaring raptors, waterholes are teeming with fish, and at night-time the land is crawling with rats.
Many species of native rat have responded to these exceptional conditions, including the common Bush Rat (Rattus fuscipes), and lesser known species of Water rat (Hydromys chrysogaster) and Long-haired rat or Plague Rat (Rattus villossissimus).
The Long-haired rat population is burgeoning so much that they’ve been tracked spreading westwards from Longreach to Birdsville and across to Alice Springs – where their last population boom dates back to 1970!
Like many other Australian mammals, native rats have evolved to take advantage of these ideal conditions. Long-haired rats can produce 12 young every three weeks in a good season; that’s one of the highest reproductive capacities of any Australian rodent! Thanks to the recent rains and the abundant selection of insects, fresh juicy roots and dense sprouting vegetation, there’s enough food and shelter for everyone.
But, the nutritious green growth, the delicious insectivorous smorgasbord and the waterholes brimming with life will inevitably disappear and when they do so will the rats. So what are the advantages of creating a population boom?
Well, firstly, rats play a vital role in food webs, helping to control other booming critters such as bugs, beetles and crustaceans. On the flipside, the rats themselves are a critical food source for owls, raptors and reptiles.
Population booms also assist our rats to disperse, giving them an extra boost to help compete with introduced species such as the Black rat (Rattus rattus) and the Brown rat (Rattus norvegicus). Natural selection ensures only the fittest native rats will survive the ‘bust’ phase, and help shape stronger future generations.
If you’re not sure whether to hurl or help the rats in your neighbourhood (or pantry, or bedside table) check out this simple guide. Happy rat spotting!!!