The opening episode shows how different species respond to the annual summer thaw of sea ice in the Arctic. The extent of the melt has been increasing in recent times, and this could be disastrous for polar bears. A mother emerges from her winter den with cubs, and leads them on to the sea ice to hunt. As the ice breaks up, the bears have difficulty walking and resort to swimming between floes. For others, it's a race to breed in the short summer season. When guillemots arrive at their nesting cliffs, the rocks are still cloaked in ice. A few short weeks later, the young launch themselves on their maiden flights, but those that crash before they reach open water present an easy meal for an Arctic fox mother and her cubs. Aerial footage shows the arrival of belugas and narwhals at the edge of the sea ice. The narwhals navigate their way along leads, but can become trapped if the ice ahead is still unbroken. In the height of summer, large parts of the Arctic Ocean are virtually ice-free, leaving some polar bears stranded on the few remaining icebergs. Those that reach dry land must wait for the winter ice to return before they can start hunting again. As the bears congregate, fights break out between the males. Nature's Great Events Diaries follows the camera team's attempts to locate narwhals in "Quest for Ice Whales".
Nature's Great Events is a wildlife documentary series made for BBC television, first shown in the UK on BBC One and BBC HD in February 2009. The series looks at how seasonal changes powered by the sun cause shifting weather patterns and ocean currents, which in turn create the conditions for some of the planet’s most spectacular wildlife events. Each episode focuses on the challenges and opportunities these changes present to a few key species. Nature's Great Events was produced by the BBC Natural History Unit in association with the Discovery Channel and Wanda Films. The British version of the series was narrated by David Attenborough. In the USA, the series was shown under the alternative title Nature's Most Amazing Events beginning on 29 May 2009 and was narrated by Hasani Issa. The title Nature's Great Events was previously used by Reader's Digest for a unrelated VHS series released in 1996. Source: Wikipedia