A Canadian teenager has been rescued unharmed, apart from minor frostbite, after drifting for almost three days on an ice floe together with two polar bear cubs and the carcass of their mother which he shot in self defence.

The 17-year-old, who was named locally as Jupi Nakoolak, was suffering from hypothermia after the temperature fell below -15C, but was otherwise well, conscious and speaking to his rescuers, who crawled across ice floes to reach him.

Nakoolak told them he shot the adult bear when it came too close, and then got as far away as possible on the ice from the cubs, which remained with the body.

He had been stranded since Saturday evening, when he and his 67-year-old uncle got into trouble during a hunting expedition and the ice floe on which he was standing broke away. Nakoolak's only food was a small package of chocolate bars, dropped late on Sunday by a small aircraft chartered by the Canadian government, but the pilot and the crew of another plane lost sight of the teenager in the gathering darkness. The search continued through the night, with flares being dropped to light up the frozen landscape. But Nakoolak was not located until daylight yesterday.

The drama began when Nakoolak went hunting with his uncle Jimmy on Southampton Island in the northern part of Hudson Bay. Their snowmobile broke down, and they set out walking towards a small settlement, Coral Harbour, about 11 miles from where they were stranded.

The pair were reported missing when they failed to return by Saturday night. The older man was picked up on Sunday morning, still searching for his nephew. A search by boat, snowmobile, 4X4s and air was launched. It was only on Monday morning that a military search and rescue plane spotted him again on the ice, which had drifted about 20 miles from where the snowmobile had broken down.

Two crew members parachuted on to a larger floe, and then crawled on their bellies to reach him. All three were then picked up by boat, and the youth was flown to join his uncle in hospital in Churchill.

Jean-Pierre Sharp, an official with the Canadian forces joint rescue co-ordination centre in Ontario, said the teenager was "in decent shape".

"Even after spending hours alone, huddling in temperatures that dipped below -15C, the teen appeared to be in decent shape. He was conscious, slightly hypothermic and appeared to have some frostbite."

Rob Hedley, the senior administrative officer at Coral Harbour, where dozens of residents had joined in the search, spoke to him when he was first taken to the local health centre.

Hedley told Canadian television: "It's quite incredible that he's in such good shape …. As much as the polar bear is a bit of a dramatic aspect of it, he had his weapon with him, thank goodness. But also it's basically surviving three days out on the land with little food or water. I was expecting this not to end as happily as it did."