When whales migrate, do they use the same path of travel each year and how do they have a sense of direction?

Question: When whales migrate, do they use the same path of travel each year and how do they have a sense of direction?
- Keywords:
  direction,
  migrate,
  travel,
  whale
Asked by michelletherezien to Charlotte, Jo, Kevin, Louise, Valeria on 18 Jun 2012.
- Joanna Cruden answered on 18 Jun 2012:
  
  Nobody really knows, some scientists think it is due to the earth’s magnetic field or they just remember the way and recognise landmarks (under the water landmarks).

Question: When whales migrate, do they use the same path of travel each year and how do they have a sense of direction?