The past year gave us a massive increase in the vole population – with a corresponding damage to fruit trees and garden plantings. I suspect it was partially due to weather or climate factors, but I think we have also lost some of our small predators. For the lack of a couple tiny weasels, I’m looking at methods of poisoning rodents. Fortunately, in one of my careers I was a county agent, so I know how to do the relevant research.
I don’t want to harm any of the little weasels I may still have – they’re cute, they help control rodents, and in general I like them. Sam’s two cats come by for vole hunting, and seem to be doing a reasonable job. The marsh hawk cruises by on his vole patrols – so while poisoning the voles is an option, I need a poison that won’t harm my allies – while bromethalin is listed as the most effective bait for voles, the Merck veterinary manual describes cats as “exquisitely sensitive.” While it isn’t proven that they can ingest enough to harm them if they dine on a vole that has been slowed by the neurotoxin, I don’t have to take the risk. Frankly, I doubt if my problem voles have developed the resistance to the anticoagulants that bromethalin replaced.
Even so, I figure I need to be developing some bait stations to limit the exposure to other animals – in other words, the poison goes into a chunk of inch and a half pvc pipe, along with a slice of apple (to attract the vole to the inside of the pipe)
Voles live only 3 to 6 months – but the little beasts can produce up to 10 litters of young each year – and each litter has three to six baby voles. Since my small predators are no longer capable of controlling the population, this year becomes the year of artificial controls.
Trego's Mountain Ear 