Scientists design contraceptives to limit grey squirrels in the UK | Hacker News Reader

Scientists design contraceptives to limit grey squirrels in the UK

bbc.co.uk

Scientists artificially select invasive squirrels who are suspicious of devices that look like a trap creating an out of control wave of super squirrels. Also, they better be certain this doesn't affect species like eagles and hawks that eat these things.

The trap design weighs the critter. Eagles and hawks in the UK are both unlikely to match the weight profile and nom on hazelnut paste.

Deployment of any device targeting wild animals like this needs approval. Processes are stringent, programs for sterilisation and release of cats took ages to get approved. Rewilding is held up for years on assessment.

This is the least likely problem with this approach. Much more likely is that it isn't sufficiently effective and surprising things happen when the grey squirrel population is suppressed, which are counter productive.

I hope it works.

Eagles and hawks eat the squirrels. I'm talking about predators.

The problem in india with vultures and diclofenac maybe isn't a good example, or warfarin and rats: the contraceptive isn't designed to kill, so its a far lower dose and there's no increased carrion risk, since it won't be killing the squirrels.

I'm not saying there's zero risk of a hormone disruptor in the food chain, but I don't think scots hawks and eagles predate squirrels as their main or sole food source: https://www.wildlifeonline.me.uk/animals/article/squirrel-pr... suggests its marginal from a squirrel population dynamic point of view.

I think the red squirrels are more at risk. https://www.northernredsquirrels.org.uk/red-or-grey/ says “Red squirrels weigh between 270-360g and with a head and body length of 19-23cm. Grey squirrels typically weigh between 400-720g with a head and body length of 25-30cm.”

That’s not a big difference (10%) between heavy red and lightweight grey squirrels. Also, that “typically” indicates the difference maybe smaller, or ranges may even overlap.

I can understand the logic behind this, but the couple of grey squirrels I get in the garden won't be replaced by red squirrels. I would miss them.

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