Rodenticides
This was a thought-provoking talk about the dangers of so-called second generation rodenticides. First generation poisons typically have a half life of 16 days. Second generation poisons have a half life of 300 days. That means an animal can consume a bait and still walk around for a vey long time with the poison in its system. It could then be attacked and eaten by another species.
Research is needed to find out which animals are resistant to the bait. Some of these animals are eaten by humans, especially in Aboriginal communities.
Testing can only be done on a dead animal. (Testing is done on the liver, which is not really possible when the animal is alive). The top predator in the wild is the eagle: a beautiful bird, often endangered without this other threat.
This talk, given by Michael Lohr from the consultancy group 360environmental, was a wake-up call about the indiscriminate use of rat poison in the community.
Lorna Glen
This talk was given by Michael’s wife, Cheryl Lohr. She is in charge of Lorna Glen, a conservation reserve near Mullewa. Her current research is how to deal with feral cats in an arid landscape. We know how to deal with foxes, which are the other big predator of native animals. The poison 1080 is typically dropped from the air. Cats don’t eat these baits. Cheryl measures how native species in WA react to 1080 poison.
The difficulty for Cheryl is that they don’t know exact how many feral cats are on the property. It’s very difficult to count them before and after putting down baits. One inexact method is to look for their paw prints crossing a dusty road for 4 nights in a row. They drag a chain over the road each night to produce a clean slate for the following night.
There are 120 wildlife cameras on the property, but the cats seem to avoid having their photo taken. The property is 250 square kilometres. There is also a huge amount of paperwork connected to animal trapping and research. After an intense trapping programme, lots of cats are eliminated, but a high rainfall event results in a successful breeding period and numbers creep up again.
These talks were given “off the cuff” by members of the DRB group, as we all sat down for a rest between our expeditions! Their son, Martin, aged about 7 or 8, then suggested that we all had our photo taken on the Flying Fox in the children’s playground:
 |
This is me having a go.
|
 |
| This is Arlene, who organised everything. |
More on pesticides at a forthcoming Nats Club talk:
Listed as a Priority 3 species in SW WA, the Masked Owl (Yornitj in the Wadandi language) is so little known that the WA Museum’s Handbook of WA Birds has no description of its nesting. For the past five years, Boyd and colleagues have tracked down and investigated through observation, photography, sound and food pellets a surprisingly vibrant peri-urban population around Margaret River of this large, charismatic but enigmatic forest relative of the Barn Owl. They have found that Yornitj is a specialist predator of rats in the peri-urban mix of remnant forest, agriculture and gardens of the Margaret River.
Ironically, this means that this is one of the most threatened of many wildlife species subject to debilitation and death through unrestricted sale and use of modern ‘one dose kills’ rodenticides. In response to this realisation, an Owl Friendly Margaret River campaign was mounted that is a model for community groups throughout Australia seeking a ban on Second Generation Anticoagulant Rodenticides (SGARs).
Bunnings advice on rodents here
