Whilst watching Frozen Planet, has it crossed your mind why the killer whales in the Antarctic are slightly off colour? This slight yellow tinge is caused by nutrient rich diatoms and algae found in these chilly waters which attach to the mammals skin. John Durban of the NOAA has offered a new proposal as to why a certain type of killer whale will migrate thousands of miles in relation to this yellow tinge.
Since the killer whales travel at a constant speed during this migration, researchers believe that they are not traveling to find prey or to give birth. Type B killer whales (which feed mainly on seals) were tagged off the Antarctic Peninsula and it was revealed that they move towards sub – tropical waters continually. One tagged individual travelled over an incredible 5, 000 miles to Brazil, only to return just 42 days later to Antarctica! The speed and distance travelled is unprecedented in killer whales and it implies the individual departed from Brazil immediately, but why?
Killer whales return from this journey to warmer seas ‘cleaner’ than when they left. It is thought the warmer water helps killer whales to shed the algal growth and regenerate skin tissue. It is possible that the energy they would need to expend in the cold Antarctic waters can be utilised to repair any tissue damage created by diatoms or algae. Further evidence for this theory is shown by killer whales actually slowing down their speed in warmer waters. They do not travel slowly enough to indicate calving or extensive feeding, but it would give the killer whales extra time in warmer waters to shed and heal their skin.
As more research is conducted on these beautiful mammals, the more we are finding out about how clever they are. This may provide interesting comparisons when researching into the evolution of intelligence and how similar to the intellectual capability of humans they may be.