"Honestly I think we're in denial about what is happening with animals. The bottom line is that by winning this, your word gets exposure," he said. The image that won him the award was that of a de-horned rhino which had been poached illegally in Hluhluwe Umfolozi Game Reserve, South Africa. With rhino horns fetching up to $127,000 a kilogram on the black market, he says the image was necessarily graphic to capture the full scale of the issue. "I was able to get pretty deep on this one. It's necessary to show an image of suffering as part of this story. If you're not doing that you're not conveying that story," he said. "We saw more than 30 carcasses but we needed to find one that was more emotional. It was likely the rhino was still alive when the horn was taken.

"It always makes you angry. I really feel for all the guys who work in this field trying to keep these animals alive. It's not a good time for them and they're working harder than ever." Stirton started capturing wildlife photography in 2007 while covering the war in the Congo, photographing gorillas who had been killed as part of the war. "I started working on wildlife in 2007. I was in the Democratic Republic of the Congo reporting on the war and I was in the right place at the right time to photograph some mountain gorillas." He said it was a turning point for him, helping him to realise that there were more than just human casualties in war. Stirton said since he began wildlife photography, he has developed an interest in telling stories that aren't often told.

He has taken a series of photo essays for Getty Images highlighting issues face by humans and animals, particularly in Africa. "I think my passion is looking at the intersection between man and environment," he said. "I first shot the rhinos in 2010 and it was all about pulling the curtain back on that. I wanted to come back to that now because it's accelerated. The wildlife space is relatively unknown. "I'm trying to be a pragmatic journalist. Both debates have some strong arguments and there are not clear mechanics to the industry. There is corruption on both sides." He said the rhino horn trade was driven by false claims it could be used as a medicine, with many people in Africa and Asia believing in its curative properties. "They're being marketed a product that's a placebo. They're being lied to. The people who market it push something onto people that simply doesn't work. It's massive exploitation and it's causing great suffering in Africa and Asia.

Loading "What we see is that it's not heavily policed. It's a wide-open system. I just think demand is the issue. If we curb demand through education we solve it." Stirton's photo essay "The Deadly Rhino Horn Trade" has been published online by Reportage by Getty Images.