I have just witnessed a Magpie taking down and killing a pidgeon / ring dove.
We keep rescue chickens in our garden, free ranging. The garden is covered by CCTV cameras. Out of the corner of my eye, I saw one of our chickens pecking at something in their run.
During the day the gates to their run are open, so they come and go as they please and have their food and water in there.
I went down to investigate and found she was pecking at a dead, headless, ring dove. After disposing of the dead bird, I went indoors to re-view the footage. To see what, or who, had killed this bird.
Two ring doves had entered the chicken run and were feeding at the food hopper. Then two magpies arrived and chased them off the food. A flight fight ensued inside the the aviary, eventually escaping through the open door and into the garden.
The cameras then clearly showed one of the magpies attacking the bird in the air, bringing it down, killing it and then consuming it. The second magpie arrived and joined in.
One of our chooks (Mabel) was fascinated and wondered over to see what the commotion was about. She chased the magpies off and claimed the prize as hers.
We have at least two pairs of magpies that regularly visit. They get on with the chickens (at arms length) and are quite wary of them.
I suspected that, being of the crow family, magpies are carniverous. But I thought it was mostly carrion they would be after. I never suspected that they would kill, and eat, other birds.
I think that the chickens are safe with magpies, they can be quite vicious themselves.
I just hope that one of ours has not got the taste for pidgeons and perhaps grab one for herself.
We know that magpies will take chicks from nests so that is live food hunting. I suspect that they will be opportunistic - it may be that the death in the fight was more accidental than deliberate. That said I once witnessed a Crow kill an unsuspecting Knot at one reserve. Everything needs to build up their own reserves at this time of year for keeping the species going.
Which country are you posting from? If UK, I am assuming you mean collared doves. You've referred to pigeons twice though, so not clear on species. Important as some dove and pigeon species can breed pretty much any time in UK. A magpie catching an adult of any pigeon or dove species would be hard going. To somehow hold down and kill also hard going. But, if you saw juvenile birds, or at least the killed one was, that would make sense.
I am in the UK. Not quite sure of the exact species of the dead bird. Probably a collared dove, as they are plentyful round here. I suspect that the killed one had gorged itself on the chicken's food, that it was too fat to fly properly. That made it easier to take down. There was a second bird, that got chased by the other magpie, but that managed to out fly the persuer.
I still think it's more likely juveniles, and there could well have been a clutch of two, with both being picked off. Magpies don't have talons. Crows don't either but are a lot larger, so more able to kill adult birds. Adult doves would take a lot of strength for a magpie to bring down, hold down, kill etc.
edit. Any website stating they've seen magpies kill collared doves, I'd respond with the same thing. Most likely juvenile doves.