Can anyone suggest suitable source to pursue for my contact?  

'I was interested to know if there have been any finds of animal victims of gladiatorial games. We know there were  cemeteries for the human casualties, and they have provided great insight into the health, physical size and cause of death for those gladiators. I think it would be tremendously exciting if we could do the same for animals, because it might also give us information about the state of the species at that time. I’ve heard it argued that the Romans came close to wiping out certain African species because of the huge number of animals being collected for the arena. I hope that makes sense, and I look forward to hearing more'

Not sure about any evidence myself.

Cheers,