A brinicle grows from the ice sheet above.
Like an "icy finger of death," this brinicle (aka brine icicle) grows from the ice sheet above in McMurdo Sound, Antarctica. Over the course of 12 hours, it descends to the seafloor below, then extends another 20 feet along the sea bed, trapping anything it touches in ice. Most creatures here move far too slowly to escape its path of death. A brinicle is formed when sea water freezes into sea ice, creating a super-salty brine. This brine percolates through cracks in the ice into the sea water below. The brine sinks because it's much denser than the surrounding water. It's also much colder, so sea water freezes on contact, forming a sinister tube of ice.
A northern gray wolf chases bison.
Running through deep snow is exhausting for the wood bison, but the compressed snow they create makes a runway for the wolves in Wood Buffalo National Park, Canada. Wood bison can run at more than 35 mph, and so can wolves. A full-grown bison is too much to handle, so this wolf and its partner will zero in on a yearling instead.
An emperor penguins leaps from the sea.
In winter, when most other life is deserting Antarctica, emperor penguins return to the southern continent. The penguins have spent the last four months feeding at sea and have put on a lot of weight. Emperor penguins are the only bird to endure the coldest winter on earth. This scene from Frozen Planet was filmed with a bespoke, winterized hi-speed camera.
Emperor penguins swim at Cape Washington in Antarctica's Ross Sea.
"Male emperor penguins dive through openings in the sea ice to take their first swim in over four months," says Frozen Planet director and cameraman Chadden Hunter. "The return of the females at the end of winter allows the males to finally go fishing again. The males have lost 40 percent of their body weight during winter. The first dip is tentative as they get a feel for the water and suck in enough oxygen to take them on 20 minute feeding dives to over 500 meters in depth."
Emperor penguins herd their chicks.
Adult emperor penguins herd their chicks into a creche (nursery) along Antarctica's Ross Sea. Within the month the chicks will fledge and set out into open water for the first time.
Eider ducks in a polynia, a semipermanent area of open water in the ice.
In March, spectacled eider ducks gather in the St. Lawrence Island polynia in the Bering Sea just off the coast of Alaska. The world's entire population of spectacled eider ducks gather at this polynia each year, which is kept open by the currents in the water below. The ice hole is a lifeline to mussels and sea urchins on the sea bed below.
An Arctic wolf at Karrak Lake in the Barrenlands of the Canadian Arctic.
"As the midnight sun glows on the horizon a lone Arctic wolf watches the crew curiously," remembers Frozen Planet director and cameraman Chadden Hunter. "Over 350 miles of barren tundra separate this wolf from the nearest humans — a species he's unlikely to have encountered before. After spotting each other on the horizon, this wolf traveled over 10 kilometers just to check us out. Completely naive and unafraid, he sniffed around our feet as our hearts pounded. He then gave us this quizzical last look and headed back across the horizon."
An underwater "icefall."
"Meltwater seeping down from cliffs above has formed a stunning slope of rapidly frozen ice crystals at Granite Harbor in McMurdo Sound, Antarctica," says Frozen Planet cameraman Hugh Miller. "The red starfish (Odontaster validus) are among the most prolific of animals around and are voracious predators on many of the other invertebrate animals found here. Although there are some very specialized fish species which survive here, the relative lack of fish numbers has enabled the starfish to fill a vacant niche and become an apex predator. This incredible ecosystem is rich with diverse life even though it is in total darkness for up to eight months of the year. During this time some animals such as the fish go into a torpid semi-hibernation-like state while others such as the starfish survive by eating rich mats of bacteria which grow on the underside of the ice."
The frozen forests of Lapland, Finland.
"Heavy snowfalls at the beginning of winter, followed by intense cold snaps, allow heavy crusts of ice layers to gradually build on the pine and birch," says Frozen Planet researcher Fredi Devas. "Though they are resistant to temperatures as low as -70°C (-98°F). The weight of the ice, which breaks branches and even snaps trunks, is a major factor in limiting how far north trees can grow."
A least weasel with bloody paws in Finland.
The smallest carnivore in the world, the least weasel is about 130 millimeters in length and weighs only 1 to 2-½ ounces. They stay active throughout the winter despite the extreme High Arctic temperatures, which can drop below -50°C (-58°F). They are voracious hunters, tracking down voles, mice and shrews that live in icy corridors below the snow. Their slim line bodies are designed to hunt in the tiny tunnels and are the same width as their prey. The snow acts as an insulator keeping the "subnivean" world at an almost constant -1°C (30°F), so despite their tiny bodies these little mammals, both predator and prey, can live comfortably even in these coldest months."
The Antarctic continent in late winter.
Katabatic winds stream down off the ice cap reaching speeds of 125 miles per hour. These are the fastest winds on our planet, making aerial filming conditions in these Antarctic valleys extremely treacherous.
An aurora australis visits the emperor penguins.
Male emperor penguins huddle against the cold beneath a spectacular aurora australis display at Auster Rookery in Antarctica. The male emperor penguins guard their precious single egg through out the winter months while the females are at sea fattening themselves up for when they take over care of the newly hatched chick.