One of my previous Rubies was a hunter/killer - not only of Collar Doves and pigeons (and the odd smaller birds) but he was also an accomplished ratter. His littermate brother who I also owned was quite clueless, but apparently their father was also a hunter. Rowan often enjoyed a tasty pigeon snack after one of his hunting sessions, the most memorable for me being a half eaten trophy being left for us on the landing one Christmas morning.
He was stealth personified and would wait patiently for hours for his prey... He was otherwise such a sweet gentle little dog you'd never believe what he got up to - he was my "Jekyll and Hyde" boy.
There's (but only for the not-so-squeamish!) a photo of him here (http://cavalierkingcharles.com/twins...s/bird_dog.jpg) after one of his successful sessions...