The boxer dog which bounced across the wide open spaces and the jackdaws in the turrets, blue dragonflies over the lake and cages of exotic birds in an alcove outside Mr Angus's study.
Yes, now you mention it, I remember the aviary in the garden area. I think one or more of the Angus daughters (Paddy?) looked after it.
Stephen Fry remembers ponies and horses, two parrots and a mynah bird in cages near the headmaster's study, and dogs — including Boston terriers, a boxer called Brutus, and another dog called Caesar.