0:00:02 > 0:00:07On Deadly 60, I've had loads of incredible animal encounters.
0:00:07 > 0:00:10Here's just one of my many favourites.
0:00:10 > 0:00:14This is Deadly 60 Bites!
0:00:15 > 0:00:19'We've just struck gold in the heart of the Amazon rainforest
0:00:19 > 0:00:23'and come across a pack of extremely rare giant otters.'
0:00:23 > 0:00:26Look at that! Wow!
0:00:26 > 0:00:30The water's just parting in front of him. He's coming right up to us!
0:00:31 > 0:00:34You can see the power of them as they swim.
0:00:34 > 0:00:38'Make no mistake. These are otters with attitude.
0:00:38 > 0:00:42'At two metres, they're as long as I am tall. A formidable force.'
0:00:42 > 0:00:46Local people call these animals river wolves,
0:00:46 > 0:00:49and it's a really apt name.
0:00:50 > 0:00:52Firstly you look in their mouths,
0:00:52 > 0:00:55and they've got canine teeth that wouldn't look out of place
0:00:55 > 0:00:57on a wolf.
0:00:57 > 0:01:01Secondly, they're the longest of the weasel family,
0:01:01 > 0:01:03and in weight - about 35 kilos -
0:01:03 > 0:01:06actually not that dissimilar to a wolf.
0:01:06 > 0:01:09And thirdly, they hunt in packs.
0:01:10 > 0:01:12This group moving along this riverbank
0:01:12 > 0:01:17are moving in unison, frightening and disorientating the fish
0:01:17 > 0:01:20and catching them down there in the dark,
0:01:20 > 0:01:23using their tactile whiskers to feel them.
0:01:24 > 0:01:28Giant otters are perfectly evolved for hunting in the murky waters
0:01:28 > 0:01:31of the Amazon basin.
0:01:31 > 0:01:34Their broad, wing-like tail is the perfect engine,
0:01:34 > 0:01:37allowing them to fly through the water,
0:01:37 > 0:01:40with webbed feet for fine control.
0:01:41 > 0:01:44And their eyesight is pin-sharp,
0:01:44 > 0:01:48but fishing blind is no problem. These awesome anglers
0:01:48 > 0:01:53use their whiskers to follow the wake of a fish long after it's gone,
0:01:53 > 0:01:56meaning prey can swim but it can't hide.
0:01:58 > 0:02:02By working together, a group of giant otters confuse their prey,
0:02:02 > 0:02:04giving it almost no chance.
0:02:04 > 0:02:08They're a deadly team both above and below the water.
0:02:08 > 0:02:10OTTER WHISTLES
0:02:13 > 0:02:17One, two, three heads come to the surface. Five heads to the surface.
0:02:17 > 0:02:20Three of them have got fish.
0:02:20 > 0:02:23That is incredible.
0:02:23 > 0:02:26You'd be hard-pressed to find any other predator in the world
0:02:26 > 0:02:31that has that kind of success ratio when they're hunting.
0:02:31 > 0:02:32OTTER GRUNTS AND CRUNCHES
0:02:32 > 0:02:36I've seen lions hunting, orca, great white,
0:02:36 > 0:02:40but none of them come even close to being as efficient as these guys.
0:02:40 > 0:02:43And that's why they're going on the Deadly 60.
0:02:47 > 0:02:49How good was that?!
0:02:55 > 0:02:58Subtitles by Red Bee Media Ltd