Snap! Winners from the wild

They are the best wildlife photographs taken in the past 12 months, and every one of them has a story to tell.

In the wilderness of Yellowstone, a halo of steam rises from a frost-encrusted bison silhouetted against the morning light, an eerie symbol of the old American West. A sad-eyed puffin pokes its clown face out between the spring flowers from a burrow after a headlong dash to safety from patrolling black-backed gulls.

In a lagoon in the South Pacific, a reef shark buzzes an encroaching diver, apparently just for fun. And a giant bullfrog battles to rescue his offspring from baking to death in an astonishing display of amphibian paternal devotion.

These are just some of the winning images of the 2001 BG Wildlife Photographer of the Year competition. Organised by BBC Wildlife Magazine, and held in conjunction with the Natural History Museum, it is the biggest and most prestigious wildlife photographic competition in the world, attracting 19,000 entries from more than 60 countries.

Tonight the 14 winners - and the three winners of the junior competition - will receive their awards and cheques at a dinner at the Natural History Museum, where the 115 best images will form a spectacular exhibition from Saturday.

Overall winner was the picture of a grey reef shark by Tobias Bernhard from Germany. Wildlife photographer Niall Benvie, one of the competition judges, said: "This picture is loaded with tension - between the warm and cool tones, and between the viewer and the subject."

It narrowly beat Mervin D Coleman of the United States, whose image of a bison fringed with rainbow colours, steaming in the morning sun on a ridge in Yellowstone National Park's Lamar Valley, won the Animal Portrait category.

The previous night had seen temperatures fall to minus 26C. "It was a magical, almost spiritual, moment," said Mr Coleman.

Runner-up in one of the Animal Behaviour categories was Mark Payn-Gill, from Bristol, who captured the dramatic image of a bullfrog and its young in a South African marsh. He said: "Schools of giant bullfrog tadpoles tend to concentrate in shallow, warm water, even though the rapid evaporation puts them at risk of becoming stranded from the main pond and consequently dying from desiccation," he said.

"Able to detect his offspring's distress, this male began digging a 30cm canal in temperatures of 35C through thick clay mud. He even leaped a metre out of the water, jaws agape, to attack me when I got too close to his charges. Five hours later, with little water left, the dam finally burst and more than a thousand tadpoles vigorously swam to freedom."