Frozen Planet - meet the penguins, wolves and whales

If you've been fascinated by the diversity of wildlife on the BBC One series Frozen Planet, read on for more incredible facts about penguins, wolves and wales. 

• Adélie penguins can dive to a depth of up to 175m and hold their breath for over 6 minutes.
   
• A foraging expedition can take an Adélie as far as 250km from its colony.
   
• Adélies breed on snow-free ground, using stones to build nests and to keep them above the level of meltwater.
   
• An Adélie chick eats 23–36kg of food before fledging at two months old.
   
• Chicks beg for food from adults by whistling.
   
• Incubation and brooding duties are shared by both parents, which take it in turns to hunt and feed.
   
• The total population of Adélies is around 2.5 million.
   
• Adélie penguins mate for life – or at least they try to find the same mate each year.

• The head of this whale comprises one-third of its body length of up to 25m; its mouth is the size of a garage.
   
• It uses its blowholes as an icebreaker, leaning its bulk against the ice and blowing to clear an airway to the surface.
   
• The bowhead may live for 150 years or more – making it one of the longest-lived mammals in the world.
   
• Unlike other whales, it lives year-round in Arctic waters off Greenland, Canada and Alaska.

• The Arctic wolf is a subspecies of the grey wolf; unlike its more southerly cousin, pack size rarely exceeds seven, and sometimes comprises just a mating pair.
   
• The permafrost underlying the tundra often makes digging dens impossible, so wolves use existing caves as dens. These are inhabited year after year by generations of the same family.
   
• Wolves can run for long periods, using stamina to wear prey out rather than relying on bursts of speed – they can continue to run for 20 minutes at a time while on a hunt.
   
• A wolf can eat up to 9kg of meat in one sitting, regurgitating scraps to feed cubs back at the den.
   

Read the rest of our Frozen Planet content here.