we haven't had a fox attack since 2020. They are all around, but they appear to not want to risk an engagement with the roos. When 5 adult roos stand shoulder to shoulder facing the perceived threat, I think most predators (including people) would think twice about it too.
Again, this situation hasn't really arisen for years. The only 'land predator' we've had to deal with is dogs - a neighbour's and walkers' dogs off leads, who presumed to chase what they like, where they like, and whose owners were incapable of controlling them. In those cases, all flock members survived, though one or two lost a few tail feathers as they scarpered. One didn't return for 3 days, but she was apparently unharmed, physically at least.
There are multiple cats, rats, adders (seen several), and almost certainly weasels (I saw one once) around, and something predated Rhondda's nest in the hedge last year. The roos sound the alarm for terrestrial threats several times a week, and the most serious level calls (which prompt the flock to respond by drawing up in close formation) are normally months apart, so threats are regularly perceived, but not often seen as serious.
The last time I saw everyone scatter into the undergrowth, it was a cheerful and stupid dog having a whale of a time, so I don't think that really counts. I think the chickens too recognised he was just a goof; everyone was back out and carrying on with their day more or less as soon as he'd gone. This was in stark contrast to their being noticeably jittery after a real attack, when historically we had them.
So, the answer is yes, to my knowledge they've all survived land predator attacks since 2020, but I think that has more to do with the presence of multiple roos on the loose than it has to do with cover. A few birds have completely vanished, but not in the context of an attack, so I don't even know if they were predated, or just met with an accident, or even just 'left home' so to speak (as young wild animals disperse). The cover protects against the aerial predators, and that it does very well, though it has in the past also served as reliable refuge and hiding place from terrestrial marauders. It helps that my most of my birds have plumage that is natural camouflage.
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