Swimming with an otter above the surface, and then below
Otters are one of the UK's most graceful and elusive animals. Yet one BBC wildlife presenter has just experienced the rare privilege of swimming with these enigmatic creatures in the sea, and in doing so has captured rare footage of otters hunting underwater.
For one man, filming British otters swimming underwater had become something of a personal obsession.
Charlie Hamilton James may be better known for his passion for another elusive British animal, the kingfisher, which he spent months filming for the recent BBC One series Halcyon River Diaries.
It is a glimpse into the truly secret world of a creature that is so good at keeping its secrets
BBC Autumnwatch presenter Charlie Hamilton James
But Charlie has secretly harboured a desire to film the otter, and to do so on its terms, under the sea where this sleek mammal occasionally ventures to hunt fish, shellfish and assorted marine creatures.
Filming an otter underwater is harder than it sounds.
Once widespread throughout Europe, the
Eurasian otter (Lutra lutra)
underwent a dramatic decline during the 20th Century, to the point where the species became rare or extinct across much of its former range.
In the UK, otter numbers fell drastically from the 1950s to the 1970s, with chemical pollution thought to be a major cause.
Although numbers are slowly recovering, the creatures remain elusive, as they tend to be solitary and prefer to be active at dusk and at night when they hunt either within inland waterways or along the coast.
Enigmatic and elusive
Despite this, Charlie Hamilton James set out to film wild British otters.
What's more he wanted to film wild cubs, which are held in a den, known as a holt, and the parents hunting underwater.
His first attempt came this summer, when he spent five weeks seeking out wild otters with no success.
This week, he tried again, along with a natural history film crew shooting for the
which begins its new series on Thursday, on BBC Two at 2030 BST.
The team, which included producer and cameraman Richard Taylor-Jones and otter expert John Campbell, began its search in Shetland, where otters spend most of their time in the sea, and mother otters are known to bring out their cubs in early autumn.