Last night, a fox came and took one of the four hens I've been looking after in Dorset. It wasn't a surprise; he'd already paid a daylight visit, in which he'd been unsuccessful, and the hen he took was injured and had chosen to spend the night in the hedge rather than in the coop. Even so, I feel upset: they were in my care, and I failed to protect them. The knowledge that the fox needed to eat isn't helping me to feel better about the chicken's death.
We identify so readily with animals. In nature documentaries it's easy to get behind a creature and want to see it succeed. Sometimes that's a prey species, under attack from a wily predator; sometimes we really want to see the predator secure its next meal. Identification with animals can be a powerful driver for conservation, prompting whole streets to come together to protect 'their' hedgehogs, for example; but it can also lead us to interfere in ways that aren't ideal.
Recently I stayed somewhere that had two Larsen traps on the lawn, with live magpies in to act as 'call birds'. The call birds attract other magpies, who can then be trapped and killed. The reason for the traps was a nesting moorhen, and blue tits who had occupied a garden nest box. Neither of these are scarce species. All three are native, going about their natural business. But the homeowner did not want to see 'their' baby moorhens or blue tits killed, and so was killing magpies instead.
The legality of this is a grey area. There were no financial interests at stake and it would not be possible to make the case that it was 'conservation', as you could with setting a mink trap, say, to protect rare water voles. It was a case of deciding on 'goodies' and 'baddies', nothing more.
The fox isn't 'bad' for taking a hen – far from it, however upsetting or inconvenient it may be. Likewise the sparrowhawk that patrols the bird feeders here, and the hen harriers who should be predating grouse moors. If we we want vibrant, working ecosystems we must to learn to accept that we won't get our own way all the time.