Jeez Spaw - Mr Next Door Neighbour who moved away last year used to keep cockatiels, I miss their chattering - the new people keep children instead, 3 noisy little ones...our ginger cat, Belle, developed quite a taste for cockatiels. We know she wasn't getting next door's so can only assume that their chattering let other birds to their big cage and Belle was feasting on the 'visitors', grey ones like yours and yellow ones too. I don't know how they would go with a computer though.
Cheers
JennieG