London: Scientists may be close to solving the mystery – whether otters can really smell their prey underwater or not.
The mystery may be solved by a wildlife expert who conducted an experiment on camera for a BBC programme.
Now Charlie Hamilton James, a wildlife photographer who has watched otters for 20 years, believes he is one step closer to proving that otters can hunt underwater not just using their touch and sight, but nose too.
In 2006, for the first time, scientists discovered that star-nosed moles could smell underwater by exhaling bubbles and sniffing them back in – and Hamilton thinks otters can do the same.
He used special infrared cameras immersed underwater next to a dead trout and waited till he saw a wild otter swimming up the river and finding the submerged fish in total darkness.
“The otter found the fish straight away.
“It just headed straight for the fish without even surfacing, it knew it was there,” The Telegraph quoted Hamilton as saying.
The footage showed a tiny bubble coming out of the otter’s nose as it touched the fish – the bubble was then sniffed back in by the otter, all in a split second.
“I always had an inkling that otters could smell underwater and I wanted to prove it.
"As it was dark and the fish was fully submerged it proved that the otters had to be using a sense other than sight or touch to locate it.
"After reviewing the footage I noticed a tiny bubble which hit the fish and was sniffed back in by the otter,” he said.
The finding will be shown as part of "Halcyon River Diaries" on Sunday evening (BBC One 7pm).