Natural Rat Managers.
By Richard Cassels.
This beautiful small hawk, a Black-shouldered Kite, has been a regular visitor to the Narara Ecovillage Floodplain since May 3. Either perched on the mulberry tree or an old power pole, or hovering like a small angel, it has been a pleasure to watch.
Two weeks ago I was lucky enough to see it drop to the ground, grab something and then fly up to a nearby greenhouse frame. On inspection through binoculars, its prey was revealed to be a rat, almost as large as itself. On hearing of this, a loud cheer went up from a local resident!
Coincidentally at almost exactly the same time Michael Lohr, a PhD student in Western Australia, published his research (1) showing that rat poisons, once ingested by rats, can go on killing anything that eats them for many months. Victims can include owls and diurnal birds of prey (like our kite), as well as to many other animals, including pets like cats and dogs. Particularly dangerous and long lasting are the so-called ‘second generation’ anticoagulant rat poisons. In comparison, ‘first generation’ poisons work more slowly and break down more quickly.
Generally, stores only carry a few 1st generation poisons, which are vastly outnumbered by 2nd generation products. If you exhausted all other possibilities (see below), and feel you HAVE to use rat poisons, read the labels carefully and choose “First generation” products that have warfarin or coumatetralyl as the active ingredients (e.g. ‘Ratsak Double Strength’ is a warfarin product and ‘Racumin’ is a coumatetralyl product). Don’t use those with brodifacoum, bromodialone or Difenacoum (eg Talon, Mortein, Ratsak Fast Action, Pestoff Rodent Bait 20R, Klerat) .
There is a poison called Cholecalciferol, which is not an anticoagulant. Found in Rampage and Solentra brands, it is said not to pass on to secondary predators. But one web site said that: “This is one of the most dangerous mouse and rat poisons on the market. Cholecalciferol, or activated vitamin D3, causes a life-threateningly high calcium and phosphorus level in the body, resulting in severe, acute kidney failure, cardiovascular abnormalities, and tissue mineralization. This can progress to life-threatening disease. Even though this is a vitamin, it is toxic to dogs, cats, and children as well as rodents”.
NB all poisons are real threats to children and pets.
Better still, use non-toxic solutions for rats: keep your place clean and tidy, secure your chicken runs and compost heaps; learn how to use rat traps, learn to live with pythons (excellent, non-polluting rat killers!), and whenever possible combat “raptor-phobia” – the view, still current in eastern Victoria apparently (2), that the only good hawk, eagle or owl is a dead one!
Living with pythons may require overcoming a fear of snakes, and does mean knowing where your python goes at night so that you do not accidentally tread on it! NB pythons are NOT poisonous . Generally they are no more dangerous than a cat or a dog- if you tread on one or try to kill one, expect it to defend itself!
NB Some consider that being knowledgeable enough to live with pythons is the hallmark of true Australian!
“Humane” rat traps are good (they catch the rat alive), and then you face the choice of delivering the animal to a remote location, or euthanasing it or despatching it yourself.
Lethal rat traps (the old fashioned “snapper” or are modern versions) are also a non-toxic solution. You will have to learn the mostly-now-lost skills of how to outwit rats (which learn fast!), and then you have to deal with blood (always put newspaper under the trap) and small corpses. And you have to make sure they don’t snap on to pets or children.
Of course cats have long been consider good natural rat catchers in Europe, Asia and North America. However they have a devastating effect on native Australian mammals and birds. At the Narara Ecovillage cats are only allowed if they are kept inside or in caged outdoor areas.
In Briskane in the past the Council use to employ rat catchers who used fox terriers. Worth a try!
Bunnings and some supermarkets also sell sound repellers. We cannot vouch for their safety: the packets say ” safer than rat poisons”, whatever that may mean. At least that solution recognises the the main objective is to keep rats out of houses, rats will always be around somewhere.
If you feel the need to use a professional pest controller, choose one like Systems Pest Management that will only use poison as a last resort.
We have inherited a wonderful natural ecosystem, with eagles, hawks, owls, pythons and rats: let them get on with it, and enjoy the wonderful spectacle of Nature at work in your own back yard.
NB THE PERSONAL OPINIONS ABOVE ARE JUST THAT-PERSONAL OPINIONS. Always do your own research, or seek professional advice, before choosing your solution.
FOR A MORE RECENT STORY ON THIS TOPIC, SEE: http://www.abc.net.au/news/2018-07-12/something-killing-barn-owls-in-victoria/9980016.
We are seriously in danger of losing many of our owls, even the most common ones like Boobook Owls.