Killer whales and Gentoo penguins

Last night was the last episode of Frozen Planet! It has been an AMAZING series and now I've decided I'm definitely going Polar travelling after Uni!

Last night's episode was called 'On Thin Ice' and investigated the impact of climate change on the poles and how this has effected the wildlife living there.  A lot of the wildlife in the poles is at risk due to climate change as their way of life on the sea ice has to change.  The 30% reduction in sea ice that has been seen since satellite records began in the 1970s has a large impact on polar wildlife.  For example, polar bears need sea ice to hunt on - with this massive reduction it means they have to return to land and their summers without food are longer and longer.
However, it is not all negative for polar wildlife - some species are now able to occupy new areas that they couldn't previously.  Killer whales (Orcinus orca) have thinner blubber and larger dorsal fins than other polar whales.  These features prevent them from moving too poleward as the presence of sea ice is too much of a challenge to swim under with their large fins.  However, since the reduction in sea ice, a significant change has been seen in the sightings of Killer whales.  The increased number of sightings further inland than before suggest that larger populations of Killer whales are now able to live and hunt in these areas previously covered in ice. [1],[2].
Another example of species thriving in these new conditions include the Gentoo Penguins (Pygoscelis papua) which were previously known to inhabit warmer islands north of Antarctica.  In the last few decades, the number of these penguins seen around the Antarctic Peninsular has increased significantly.  This is due to the warming of the seas around the peninsular and the reduction in sea ice. [1]

If you haven't been watching frozen planet...go to BBC Iplayer NOW while the whole series is still online!

References:
[1] BBC Frozen Planet (http://www.bbc.co.uk/iplayer/episode/b00zj39j/Frozen_Planet_On_Thin_Ice/)
[2] Higdon, W & S. H. Ferguson (2009), 'Loss of Arctic sea ice causing punctuated change in sightings of killer whales (Orcinus orca) over the past century', Ecological Applications, 19, 1365-1375.