We recently encountered a rat plague of native Long-haired Rats (Rattus villosissimus) at Ethabuka Reserve, Wangkamadla country during our annual fauna survey. Native long-haired rats are well known for their population eruptions which has earned it its other common name of Plague Rat!
Many years ago, I was a ‘Ratcatcher’, the affectionate term given to members of the Sydney Uni Desert Ecology Group, one of Bush Heritage’s oldest scientific partners. I did my PHD from 2006-2010 out here in the Simpson Desert.
Now I’m back on this beautiful country working as an ecologist based on Pilungah Reserve, Wangkamadla country. Funnily enough, I never caught any rats during my PhD, so it was a nice surprise to catch my first one when helping out the Sydney Uni mob as a Bush Heritage ecologist on Ethabuka in May this year.
The chenopod floodplains of the Mulligan River on Ethabuka were teeming with so many rats that we almost couldn’t keep up.
We had to stop measuring them after the first two days. Almost every Elliott trap contained a rat (one contained two!). We pulled out up to 18 rats from a single pit trap. It’s hard to know how many we missed as the rats had chewed through the bottoms of the traps to escape. We even caught a rat in a funnel trap, but most were smart enough to simply hop or chew themselves out.
On the third day, when we were closing traps, we simply pulled the pins of the Elliott traps to release the animals (pictured to the right).
All rats were in great condition and the first day’s data suggested that they seemed to be at the end of the plaguing stage as there were many subadults, but only some juveniles and adults. All mature females had stopped breeding. We also know from marking the rats with marker pen under their foot or the base of their tail, that most individuals were new animals (never previously caught). There were only two recaptures in total from around 80 rats per day.
The rain, however, put our work to a temporary stop. I am glad I left the cameras in place on three of the most active grids to see how the populations go after the rain. I wish I had taken more photos, but there should be even more rats soon and it will be interesting to find out how much further they have moved into the dune country when we continue our surveys.
I really like rats and have worked on this particular species up in the Top End during my first post-doc expedition. To convince others that rats are cute, I attached some more cute photos. If you are interested in finding out more about the native Long-haired Rat, I suggest environmental historian Tim Bonyhady’s 2019 book The Enchantment of the Long-haired Rat.
Cheers from your ratty ecologist at soggy Pilungah,