Rare Indian rhinos face threat from poachers

As night falls over the lush plains of India's Kaziranga national park, a small group of lightly armed forest guards sets out on foot to protect the world's largest population of one-horned rhinos.

These men with their aging rifles and small plastic torches are on the front line of the battle against increasingly sophisticated international poaching networks that prey on the rare animals, entering the park under cover of darkness to kill them for their horns.

A decade ago, India had all but declared victory over poaching in Kaziranga, a 430-square-kilometer protected area of forest in the northeastern state of Assam that is home to around 2,500 rhinos.