We have some blackbirds nesting in our bush, I saw a magpie manage to pull both of the chicks out of the nest and attack them before I managed to chase it away.
The chicks looked scared but unharmed so I put them back into their nest. However, I could already see the magpie circling the nest as soon as I went back inside.
Is there anything I can do to protect the blackbirds since I know the magpie will definitely get them as soon as I stop watching?
I totally empathise. I'm slightly guilty in a limited way. I think, for me, (and each to their own), I put it down to two things. 1) species 2) stage of attack. Clearly, the first point is discrimination, but from a conservation and biodiversity point of view, better that common species are preyed upon than Schedule 1 species. One example is if I see a sparrowhawk on a post in July, looking up at an active house martin nest, I try and discourage it.....if I saw a sparrowhawk in exactly the same place in January, I go and get my camera....That example covers both points so saves me typing more!
Last year I watched a magpie stalking a young starling in one of our flower beds. It used foliage for cover as it stealthily approached and it was successful in dispatching the starling, which had flown into the garden. My wife was horrified, but as I said, it's nature, let them alone. As the saying goes, "red in tooth and claw".
That example is a good one for me to relate to my post. For that one, I'd say it ticks both 1) and 2) and I'd therefore have disturbed the magpie. The difference is the starling would have a very reasonable chance of going on to reach adulthood from that point. A chick in a nest wouldn't. Starlings are in decline. Yes, the magpie would then have tried to replace that lost food with something else, but may have been a more numerous species or non-bird related. Hard to argue that's best practice though! Just my opinion.