The fin whale is the second largest animal on Earth, next to the blue whale. Fin whales can be up to 27m long and weigh up to 80,000kg, though fin whales in the Northern Hemisphere are slightly smaller. They can live for 100 years or more. Fin whales live in all oceans, with preference for temperate and polar latitudes. Most fin whales appear to be migratory, spending the spring and summer in feeding in higher latitudes and travelling to lower latitudes. A few non-migratory populations of fin whales exist, such as those in the Gulf of California and the Mediterranean Sea. Fin whales in the northern and southern hemispheres do not spend the same months nearer the equator, and so do not interact. Their colouration is asymmetrical; the left side of their lower jaw is dark while the right...