Whales from the air
Seeing them from the shore or from a boat is terribly exciting, but from up above, you see behaviour that is almost impossible to understand from the ground.
'It's really only from the air that you realise how tactile they are. Whales are almost always touching. They touch fins, they touch cheeks, they rest their tails on each other's backs,' says Evan.
'The babies, especially, are just like human babies. They want their mother's touch. It's especially lovely when their mothers turn over so that the babies can come onto their stomachs to be cuddled. Their mothers stroke them with their fins.'
But it’s not only about mothers and babies. There are also mating groups, and whales leaping again and again into the air, crashing down in a massive spray.
Walker Bay off Hermanus sometimes has more than a hundred whales cavorting, resting, mating and nursing.
Southern right whale milk is some of the richest in the world. The babies are born weighing a ton or more and will drink 600 litres of milk a day, resulting in a daily weight gain of 80kg.
Mothers will often turn over onto their backs and invite their babies onto their stomachs. Whales are exceptionally supple and can bend in two.
Southern rights don’t seem to eat very much while out of the Antarctic, where their main diet is krill. As a result, nursing females can lose up to 20% of their 60-ton bodyweight.
About 4% of all newborns are white. As they grow older, they become grey or brindled. No one is sure how old whales can get, but some say they can reach 100 years of age or more.
Many males will mate with one female, but it's all quite gentle, says Evan. Southern rights are easy to identify because of their size (like a bus) and the white callosities around their heads.
Mothers and babies are almost inseparable. Boats are not allowed to approach mother-calf pairs. But they don't react at all to a plane in the sky.