by Rick » Thu Nov 09, 2017 10:11 am
The biggest threat to a non-wild bird here in the UK is probably crows/rooks/magpies because they are far more prevalent and widespread than sparrowhawks or peregrines. As soon as they see a bird that doesn't act normally they will mob it to death or at the very least chase it well out of their territory - I am speaking from falconry experience as my hawk was too big for them to intimidate but they were merciless in their attempts whilst she was still young and inexperienced. But this does have the tremendous upside that they make such a huge noise and tend to fly high and dive in a very eye catching way that if you are quick you can use them to trace the exact location of a lost bird.
We have wild parrots in some parts of the UK that survive all year and breed (over 50k apparently), it is not necessarily the colour or species of bird that will make it a target as much as its behaviour. Yes albinos etc become a target, but so would a hand or cage reared crow if you released it because it doesn't know how to behave and predators instinctively pick up on even the smallest signs of weakness and will become more brazen when they are confident they will get a successful hunt - hence why the usually very timid hawks/falcons will swoop within feet of a human to take a completely unaware parrot.