This stunning picture of an alligator looks like it's been photoshopped. Amazingly, it's not been manipulated at all—which is why it's snagged a prize in the UK Natural History Museum's wildlife photographer of the year competition.

Photographer Larry Lynch explains how he caught the image, and why the eyes are glowing bright red:

One evening, while walking along the riverbed of the Myakka River State Park in Sarasota, Florida, USA, one evening, Larry came across a group of alligators. It was the dry season, and they had been gorging on fish trapped in the pools left behind as the water receded from the river. One big alligator had clearly eaten its fill. ‘It wasn't going anywhere in a hurry,' says Larry. ‘So I set my tripod and camera up about seven metres in front of him and focused on his eyes.' Just after sunset, Larry set his flash on the lowest setting to give just a tiny bit of light, enough to catch the eyeshine in the alligator's eyes. Like cats, an alligator has a tapetum lucidum at the back of each eye – a structure that reflects light back into the photoreceptor cells to make the most of low light. The colour of eyeshine differs from species to species. In alligators, it glows red – one good way to locate alligators on a dark night. The greater the distance between its eyes, the longer the reptile, in this case, very long.

You can see more winning entries from the wildlife photographer of the year 2012 competition on the Natural History Museum website. [NHM]

Image by Larry Lynch /2012 Veolia Environnement Wildlife Photographer of the Year