• Evolution

  By attaching cameras to the backs of penguins, researchers have gained new understanding of how they hunt.
  
  To find out how penguins find their food, Yuuki Watanabe and Akinori Takahashi (National Institute of Polar Research, Tokyo) strapped video cameras and accelerometers to 11 Adélie penguins in Lützow-Holm Bay, Antarctica. Previous researchers had conducted similar studies but had been limited by technical difficulties, prompting Watanabe and Takahashi to use this mix of video and indirect data (which included temperature changes in the digestive tract, beak-opening and head-turning).
  
  The data collected taught researchers a lot about how penguins hunt. When they are hunting fish they stuck to shallow dives, but when hunting krill - their preferred food - they made both deep and shallow dives. Though hunting krill was less reliable, the penguins were extremely efficient in both strategies and no penguin was unsuccessful throughout. In around 85 minutes of footage, they caught 244 krill and 33 fish.
  
  When hunting krill, the penguins employed a strategy of swimming upward and then making quick, darting movements with their heads to catch them. Despite the krill's escape behaviours penguins could catch around 2 per second. Instead of escape manoeuvres the fish relied on camoflage to blend in with the surface from below, but the penguins could regularly catch them (with a frequency that surprised the researchers).
  
  Despite being a basic and common activity, foraging is not well understood in many animals - particularly marine species - and the team believe their technique will yield similarly-illuminating results with other animals.
  
  To see the video, click on the links or go to: http://www.youtube.com/watch?v=53tT0G8zacA
  
  Photo credit: Greg Marshall.
  
  http://www.bbc.co.uk/nature/21125022
  
  http://www.livescience.com/26454-penguin-cam-reveals-hunting.html
  
  http://www.pnas.org/content/early/2013/01/16/1216244110