Don’t underestimate the biodiversity threat from wallaby
In response to Bud Jones (May 27), the biodiversity and pastoral threat from wallaby, particularly in South Canterbury, should not be underestimated. Wallaby have been declared a pest in the Regional Pest Management Plan (RPMP). They continue to spread to new areas despite the best efforts of agencies and landowners.
Numbers have increased dramatically since the early 1990s when a wallaby control unit was disbanded and landowners took responsibility for the pest.
To give an idea of the rate of increase, a few bennett’s wallaby were introduced in 1874 at Waimate. By 1911 the population covered 16,000 hectares. During the 1940s the Department of Internal Affairs despatched over 100,000 wallaby in a decade but hardly made a dent in the population.
Now they range over 450,000 hectares, about 80,000 more than in 1990.
There are two main management objectives in the RPMP – to make sure wallaby do not exceed a specified level within the Wallaby Containment Area (defined in the Plan) and to prevent the establishment of wallaby outside the containment area. Land occupiers are responsible for maintaining wallaby populations below the specified level.
Environment Canterbury will eradicate wallaby outside the Containment Area where it is feasible to do so. A few wallaby have spread outside the Containment Area. The most successful management method is dogs finding the animals which are then dispatched.
We would welcome new ideas on control and containment of wallaby and other pests.
TOM LAMBIE Commissioner, Environment Canterbury
Bovine Tb
Figures just released by Nathan Guy, Primary Industries Minister, in response to a request by Richard Prosser of NZ First, show that in the period 2007 to 2014 a total of 124,213 possums were autopsied and the number found to be infected with bovine Tb was 54.
Yes, that's right – only 54 possums were found to have Tb. And yet we are told that 1080 poisoning is essential to halt the spread of Tb in our cattle herds.
This cruel and monstrous nonsense has been going on far too long and is doing great harm to our native birds and other species for no good effect. Everybody in their right mind knows that bovine Tb is spread by stock trucks not possums. DAVID MACK
Blenheim
Brodifacoum
During Prince Harry’s visit to sanctuary Ulva Island off Stewart Island, DOC ranger Dale Chittenden said Ulva represents New Zealand “the way it used to be”. That claim is flawed.
Chittenden seems unaware NZ’s original ecosystem evolved under browsing by moas and other vegetarian birds. To understand NZ’s vegetation evolution and ecosystem functioning, he should read a recent book, The Third Wave by conservationist Bill Benfield.
Two years ago, I visited Ulva Island on a tour, as Harry did, but I perceived a lack of birds. I noticed far more bird life around Oban than Ulva. Ulva had/was/is subjected to brodifacoum poisoning.
Brodifacoum, the basic ingredient in common rat poison, is worse than controversial 1080 poison. It takes 20 days to cruelly kill. During which predators eat ailing prey, ingesting brodifacoum and scavengers (eg, pigs) eat toxic carcasses. Brodifacoum residues accumulate, making Marlborough Sounds wild pigs unsaleable on health grounds.
Not to be sold, but it’s okay for Kiwi hunting families to dine on brodifacoum-laden wild pork. TONY ORMAN
Blenheim