A leading British wildlife charity appealed for volunteers on Saturday to help guard its herds of black rhino which are being targeted by poachers. The poachers are thought to have staked-out the foundation\'s two wild animal parks in Kent: Port Lympne near Ashford and Howletts near Canterbury. After receiving a specific warning from police this week The Aspinall Foundation is recruiting volunteers to help keep watch for any suspicious activity at the parks. Aspinall Foundation, chairman, Damian Aspinall said: “It is tragic and beyond belief that, as we do everything possible to restore these magnificent animals safely to the wild, the traders who seek to profit from their slaughter should bring their vile activities to the UK.\" The foundation has successfuly bred 33 baby black rhino in captivity over the last seven years. Three of the foundation’s rhino were returned to the wild in Tanzania in East Africa nine months ago. Poachers in Africa hunt rhino for their valuable horns which some people believe can be used as powerful medicine. They hack the horns from the animals\' corpses. The horn is then illegally traded , often for more than its weight in gold.