This lighthearted documentary series profiles remarkable animals across the globe. This edition focuses on a dolphin with impressive powers of sonar that enable him to locate objects using just sound waves. Milo the dolphin is helping scientists in Belgium better understand the technique of ‘echolocation’. The film also meets two blind people who have adopted similar methods to help them navigate obstacles in everyday life.

“Milo’s a smart dolphin,” says dolphin trainer Sander. “He wants to play but he’s a thinker also. He understands what we mean and what we want from him.” Standing by the swimming pool at Boudewijn Sea Park in Bruges, Belgium, Sander watches his favourite student cavort in the air and dive through the water. Eight-year-old Milo responds to Sander’s clicks, claps and commands, and forms part of a popular dolphin show at the sea-life centre.

Milo’s skill and intelligence have also brought him to the attention of scientists, and he is the star member of a research team into dolphin behaviour. Milo has demonstrated remarkable powers of ‘echolocation’ – the ability to pinpoint objects using sonar. All dolphins are equipped with a rapid, high-frequency sonar emitter, and Milo has proven himself to be particularly adept at using it.

In the pool, Milo is set the challenge of locating a football-sized object as it is lowered into the water some 11 metres away. He swims obediently behind a metal screen, which blocks his vision. A hole in the screen then allows Milo’s sonar pulses to flood the pool. Using just his sonic clicks, Milo detects the steel ball and swims out to retrieve it.

Such a remarkable ability may seem the sole preserve of dolphins in their underwater environment, yet humans are also capable of learning echolocation. In Poole, a blind eight-yearold boy has been practising the art of sonar. Sam makes clicks in his mouth to detect objects around him. Walking down the street, the minute echoes of his clicks rebound off vans and lampposts, helping him to negotiate his path. “If I click, I can hear echoes off walls and stuff,” Sam explains. “If you can’t see, your other senses get better. Bats use it and dolphins. It really helps me.”

Young Sam has only been learning echolocation for five months, while 42-year-old Californian Dan has been using the technique for most of his life. Like Sam, Dan uses clicks to navigate obstacles and can even describe the size and texture of the object in front of him. He travels to Belgium to meet expert Dr Magnus Walberg, who is fascinated to see echolocation put to use by a human. “I’ve been studying echolocation for many years in animals, but I’ve never been able to ask the animals how they really feel about their
ability,” he says.

Dan and Milo now go head-to-head in a unique test of their echolocation abilities. Man and dolphin are set the challenge of identifying the same series of random objects using just sonar. To make things more even, Milo is given eye patches to ensure that he cannot see. In the pool, Milo quickly demonstrates his superior echolocation skills by retrieving each object in a matter of seconds. In a nearby sports hall, meanwhile, Dan finds it much harder to track down the items hanging from the ceiling – although he does show an uncanny ability to identify the texture of an object without touching it.

However, there is no doubt that Milo’s super sonar has won the day – the dolphin is capable of emitting hundreds of clicks per second, while Dan can manage only one. With his dominance no longer in doubt, Milo faces his ultimate challenge. Can he locate a tiny steel ball one centimetre wide from a distance of 11 metres using just his sonar?

About the author

  • Anonymous

    Although I was interested in the programme on Milo and the research he was involved in, I found it rather upsetting that he passed away at the age of eight years. This is such a young age for a dolphin to die and wondered if this might have had anything to do with him being in captivity. I would wish simply to find out what happened to him.


  • BBC One
  • BBC Two
  • BBC Three
  • ITV1
  • ITV2
  • 4
  • E4
  • Film4
  • More4
  • Five
  • Fiver
  • Sky1