Watching a rhino being dehorned was both the highlight and low point of former Royal Marine Thomas ‘Sully’ O’Sullivan’s deployment to Africa as a volunteer with Veterans for Wildlife.

Dehorning, in which a rhino’s horn is humanely removed to make it a less attractive target for poachers, is a tactic employed in the fight to preserve the iconic species.

Sully, 32, from Poole in Dorset, spent five weeks at Thula Thula Game Reserve in South Africa’s KwaZulu-Natal province. He used his experience gained over three tours in Iraq and two in Afghanistan to train anti-poaching unit rangers in basic military tactics to better equip them to take on heavily armed poachers.

He also advised reserve management on how to improve their security and risk management procedures, with a view to hardening the security posture on the reserve.

A rhino should have a horn. It’s like shaving off a lion’s mane – it is one of its defining characteristics, but if we hadn’t done it they would have been poached in a short time. It’s not just the animals I wanted to protect; I wanted to protect the rangers and help them do their job. My deployment helped me grow as a person. The anti-poaching rangers have it a lot worse than what I thought. Seeing the dire straights that wildlife is in brought home to me that we need to do a lot more. Charities like V4W are pushing it and doing it.