Oral contraceptives for squirrels are working, a study has shown and so the UK government is keen to try to use this to reduce the grey squirrel population.
There have been many commentators over the years that have suggested that reducing one species to benefit another is somehow racist. Were both species native, this suggestion might have some justification, but they are not.
Grey squirrels were bought to the UK about 150 years ago. They do significant amounts of damage to our native trees, as well as all sorts of human infrastructure such as electricity network. Furthermore, they carry an illness which, while little impacting them quickly kills reds. For this reason you never see the two species of squirrel living next to each other. In order to make sure that grey squirrels and not other species eat the contraceptives, scientists have designed a special feeder with a weighted door, that will exclude most other wildlife, while allowing 70% of the grey squirrels in.
I have written in the past about the reintroduction of pine martens to drive out the grey squirrels. Unfortunately the pine marten is a shy animal so totally unsuited to living in our big cities. This is why I find this news so exciting. If this contraceptive was used heavily in places like London and Edinburgh for a few years, then the city squirrel population would start falling fast. Without these large city populations to keep building populations of squirrels around the big cities, these populations would be destroyed far easier by pine martens and other control mechanisms.
Is this what the UK has been looking for? In Ireland, with its far greater area of forest, pine martens were about to largely drive the grey squirrel out. In England there are large populations of grey squirrels in places that pine martens will never enter, so we need more methods. These contraceptives may well be the extra tool, to help Ireland destroy the few remaining grey squirrel refuges that remain
