Thanks v much for replies.
TBH I don’t feel like taking it to a rescue centre - or trying to - we have an awful lot of magpies around here and we’re much more fond of the smaller birds they typically prey on.
Dh put out a load of dried mealworms yesterday, for the ground feeders - magpie was busy picking up beakfuls and burying them in the lawn! Presumably it can’t be too hungry, then.
I wasn’t aware that magpies buried food, but then jays, also I think crow family, do. We often find a baby horse chestnut growing a long way from the nearest HC tree, so I suspect it’s down to the jays that we see now and then, though more often in winter.