1 00:00:10,300 --> 00:00:13,300 A "weasel". 2 00:00:14,240 --> 00:00:18,440 How we might describe an untrustworthy person. 3 00:00:20,280 --> 00:00:22,720 It conjures up images of deceit 4 00:00:22,720 --> 00:00:24,760 and betrayal. 5 00:00:26,200 --> 00:00:30,440 Members of the weasel family are often portrayed as villains, 6 00:00:30,440 --> 00:00:34,520 and associated with somewhat unsavoury behaviour. 7 00:00:37,200 --> 00:00:39,440 We "badger" people, 8 00:00:39,440 --> 00:00:41,640 "ferret out" the enemy, 9 00:00:41,640 --> 00:00:44,040 "weasel" out of things. 10 00:00:46,120 --> 00:00:49,120 But do they deserve this bad reputation? 11 00:00:51,560 --> 00:00:54,600 Now, with ground-breaking science... 12 00:00:54,600 --> 00:00:57,280 We realise, this guy's a genius. 13 00:00:59,760 --> 00:01:02,360 ..extraordinary behaviour... 14 00:01:02,360 --> 00:01:05,080 They are essentially a super predator. 15 00:01:06,840 --> 00:01:10,920 ..and by following the adventures of a wild stoat family... 16 00:01:13,520 --> 00:01:16,560 ..we'll step into the world of weasels... 17 00:01:20,000 --> 00:01:23,440 ..and finally reveal their true nature. 18 00:01:41,400 --> 00:01:44,840 The weasel family are also known as the mustelids. 19 00:01:44,840 --> 00:01:48,640 They're one of the most varied animal groups in the world. 20 00:01:52,320 --> 00:01:56,360 The 65 different species are found almost everywhere, 21 00:01:56,360 --> 00:01:59,400 from the Arctic... 22 00:01:59,400 --> 00:02:00,920 ..to the tropics. 23 00:02:03,680 --> 00:02:06,920 From the biggest - the two-metre giant river otter 24 00:02:06,920 --> 00:02:09,200 that's adapted to life below the surface... 25 00:02:11,120 --> 00:02:14,440 ..to the smallest - the 50-gram common weasel 26 00:02:14,440 --> 00:02:16,680 that gives this animal family its name. 27 00:02:21,560 --> 00:02:26,200 They may look different, but they're united by a special set of skills. 28 00:02:28,600 --> 00:02:32,520 It seems they can conquer anything, from the tallest trees... 29 00:02:33,800 --> 00:02:36,840 ..to snow-topped mountains and raging waters. 30 00:02:39,000 --> 00:02:42,120 They have to survive in a world 31 00:02:42,120 --> 00:02:46,360 where predators and prey outsize them. 32 00:02:46,360 --> 00:02:48,840 But whether they're a stoat, 33 00:02:48,840 --> 00:02:52,280 ferret, honey badger... 34 00:02:52,280 --> 00:02:56,120 ..weasel or a wolverine... 35 00:02:58,160 --> 00:03:01,160 ..they don't let anything hold them back. 36 00:03:12,760 --> 00:03:15,600 Stoats and weasels are native to Britain, 37 00:03:15,600 --> 00:03:18,920 and nearly a million roam the countryside. 38 00:03:18,920 --> 00:03:23,720 But to get more than a glimpse of one would be exceptional, 39 00:03:23,720 --> 00:03:28,000 because these animals, like all of their kind, are amongst the most 40 00:03:28,000 --> 00:03:30,000 secretive on Earth. 41 00:03:32,360 --> 00:03:36,600 That's what makes this corner of Yorkshire so extraordinary. 42 00:03:38,120 --> 00:03:40,240 It's spring. 43 00:03:45,240 --> 00:03:49,520 A young female stoat is looking for a place to start her family. 44 00:03:53,040 --> 00:03:55,800 This is Bandita. 45 00:03:58,240 --> 00:04:01,840 She will give us a unique chance to follow one of these elusive 46 00:04:01,840 --> 00:04:03,720 animals in the wild. 47 00:04:06,960 --> 00:04:11,040 Because even when she disappears, we can still see her. 48 00:04:14,680 --> 00:04:17,800 Bandita lives in a garden unlike any other. 49 00:04:25,480 --> 00:04:28,520 This may look like an ordinary garden, but it's designed and built 50 00:04:28,520 --> 00:04:31,640 all around the lives of stoats and weasels. 51 00:04:34,040 --> 00:04:36,240 We've got all sorts of different habitats. 52 00:04:36,240 --> 00:04:39,480 Not only have we got the habitats, we've actually got nearly 50 cameras 53 00:04:39,480 --> 00:04:41,600 covering their secret lives. 54 00:04:45,760 --> 00:04:49,840 This is wildlife artist and photographer Robert Fuller. 55 00:04:53,200 --> 00:04:57,280 His passion for stoat surveillance knows no bounds. 56 00:05:03,600 --> 00:05:06,920 He's spent years creating a whole world for them. 57 00:05:09,840 --> 00:05:12,920 So the main area of the garden is Stoat City. 58 00:05:15,840 --> 00:05:17,680 Lots of dry-stone walling. 59 00:05:20,520 --> 00:05:23,400 Secret tunnels leading to nesting chambers. 60 00:05:25,560 --> 00:05:28,880 And this is a great area for them to run around and explore in. 61 00:05:32,400 --> 00:05:35,040 Stoat City didn't seem to be big enough for the stoats. 62 00:05:35,040 --> 00:05:37,880 They've even gone into our parts of the garden. 63 00:05:37,880 --> 00:05:39,600 They're in the veg patch. 64 00:05:41,000 --> 00:05:44,240 All over the children's climbing frame and trampoline. 65 00:05:44,240 --> 00:05:46,520 Literally going everywhere. 66 00:05:47,960 --> 00:05:52,960 Rob has also catered for the stoats' smaller cousin, the weasel. 67 00:05:52,960 --> 00:05:55,440 The back garden's Weasel Town, 68 00:05:55,440 --> 00:05:57,400 and it's all on miniature scale 69 00:05:57,400 --> 00:05:59,720 because the weasels are so much smaller. 70 00:05:59,720 --> 00:06:01,800 They've got log piles... 71 00:06:03,400 --> 00:06:05,240 ..hidden nests... 72 00:06:06,800 --> 00:06:09,320 ..and even ponds just for the weasels. 73 00:06:12,760 --> 00:06:16,000 I enjoy watching the stoats so much, I've actually built my own hidden 74 00:06:16,000 --> 00:06:18,600 tunnel underground, so I can get closer to the stoats 75 00:06:18,600 --> 00:06:20,520 without disturbing them. 76 00:06:32,640 --> 00:06:36,880 This stoat-and-weasel wonderland will reveal the hidden lives 77 00:06:36,880 --> 00:06:39,320 of these intriguing animals. 78 00:06:46,880 --> 00:06:51,520 Rob and his family spend their free time watching the latest action 79 00:06:51,520 --> 00:06:54,160 streaming live throughout their house. 80 00:06:56,840 --> 00:07:00,240 And now they're hoping to follow Bandita's new family. 81 00:07:04,800 --> 00:07:07,160 Rob's been recording Bandita's adventures 82 00:07:07,160 --> 00:07:09,600 since she was born here two years ago. 83 00:07:15,360 --> 00:07:19,560 As one of eight kits, she spent her first few weeks with her siblings, 84 00:07:19,560 --> 00:07:21,880 cuddled up for warmth in their nest. 85 00:07:21,880 --> 00:07:24,320 WEASELS SQUEAK 86 00:07:28,840 --> 00:07:34,160 As they fed from their mother's rich milk, they grew quickly... 87 00:07:36,600 --> 00:07:38,680 ..and after just 12 weeks were able 88 00:07:38,680 --> 00:07:40,400 to live independently. 89 00:07:42,880 --> 00:07:47,000 Now, two years on, Bandita is pregnant, and she's come back 90 00:07:47,000 --> 00:07:49,600 to Stoat City to start her own family. 91 00:07:50,960 --> 00:07:53,480 The body shape changes really significantly. 92 00:07:53,480 --> 00:07:57,360 The pregnancy goes really low down between the back legs. 93 00:07:57,360 --> 00:07:59,960 So she's almost engaged, really, to give birth. 94 00:08:02,120 --> 00:08:05,840 Rob leaves food out for all the wild animals in his garden. 95 00:08:07,760 --> 00:08:10,760 To prepare for her new arrivals, Bandita must stock up 96 00:08:10,760 --> 00:08:14,320 on these offerings and find somewhere safe to nest. 97 00:08:17,680 --> 00:08:22,080 Bandita is about to have the toughest few months of her life. 98 00:08:22,080 --> 00:08:24,840 This first-time mother will have to draw on all 99 00:08:24,840 --> 00:08:27,960 of the skills the mustelid family are famous for. 100 00:08:32,040 --> 00:08:36,120 One of these is the unflinching ability to take on anything 101 00:08:36,120 --> 00:08:38,080 and everything around them. 102 00:08:42,880 --> 00:08:46,680 The boldest of the family takes that to extremes. 103 00:08:46,680 --> 00:08:48,880 The honey badger. 104 00:08:50,560 --> 00:08:54,400 Living in the African bush, they cause havoc wherever they go. 105 00:08:54,400 --> 00:08:56,560 GROWLING 106 00:08:56,560 --> 00:09:01,720 Daring and dangerous, they'll face up to lions, hyenas... 107 00:09:04,360 --> 00:09:06,800 ..and even venomous snakes. 108 00:09:14,120 --> 00:09:16,520 But they don't just have brawn. 109 00:09:18,280 --> 00:09:22,080 They also have surprisingly large brains for their size. 110 00:09:24,280 --> 00:09:27,040 It's even thought that honey badgers might be some of the most 111 00:09:27,040 --> 00:09:29,440 intelligent animals on the planet. 112 00:09:32,200 --> 00:09:34,360 But just how clever are they? 113 00:09:38,640 --> 00:09:44,400 South Africa, home to the Moholoholo Wildlife Rehabilitation Centre, 114 00:09:44,400 --> 00:09:48,440 and a remarkable rescued honey badger 115 00:09:48,440 --> 00:09:50,080 called Stoffel. 116 00:09:52,320 --> 00:09:56,160 He became notorious for his ingenious escape antics. 117 00:10:00,160 --> 00:10:02,280 You really want to know what Stoffel's like? 118 00:10:02,280 --> 00:10:05,320 You want to bring back memories and nightmares? 119 00:10:06,960 --> 00:10:09,720 Brian Jones runs the centre and couldn't believe 120 00:10:09,720 --> 00:10:12,640 the extraordinary lengths Stoffel would go to. 121 00:10:17,480 --> 00:10:20,000 He was escaping through electric fences. 122 00:10:20,000 --> 00:10:21,960 He opened doors and latches. 123 00:10:23,320 --> 00:10:25,720 Then we realise, this guy's a genius. 124 00:10:25,720 --> 00:10:27,440 He dug these rocks up and rolled 125 00:10:27,440 --> 00:10:29,320 them with his back feet and he escaped, 126 00:10:29,320 --> 00:10:31,280 so we had to take all the rocks out. 127 00:10:31,280 --> 00:10:33,040 It had been raining and he made 128 00:10:33,040 --> 00:10:35,240 some mud balls and he rolled these mud balls 129 00:10:35,240 --> 00:10:37,800 to the corner of the wall and got out with the mud balls. 130 00:10:37,800 --> 00:10:40,680 It's just phenomenal, his escaping antics. 131 00:10:40,680 --> 00:10:45,120 This certainly suggests brain power, 132 00:10:45,120 --> 00:10:48,560 but how does it stand up, scientifically speaking? 133 00:10:55,640 --> 00:10:58,720 Dr Natalia Borrego studies animal intelligence. 134 00:11:00,360 --> 00:11:03,080 Honey badgers are really cool. 135 00:11:03,080 --> 00:11:05,640 They have these really complex ecological lives, 136 00:11:05,640 --> 00:11:07,280 these very broad diets. 137 00:11:07,280 --> 00:11:09,080 So they need to climb, they need to dig. 138 00:11:09,080 --> 00:11:10,600 They do these behaviours that 139 00:11:10,600 --> 00:11:12,920 indicates a high level of intelligence, 140 00:11:12,920 --> 00:11:15,080 but we haven't actually tested that yet. 141 00:11:16,440 --> 00:11:18,840 Stoffel's more obliging son Stompy... 142 00:11:20,400 --> 00:11:22,520 ..and another rescued honey badger, Julius, 143 00:11:22,520 --> 00:11:24,400 are taking on the challenge. 144 00:11:25,920 --> 00:11:28,600 This is a specially designed puzzle. 145 00:11:29,880 --> 00:11:34,480 Inside the box will be food covered in honey - their favourite treat. 146 00:11:36,720 --> 00:11:40,160 To open the door, they must lift the wooden bar. 147 00:11:42,200 --> 00:11:45,240 This tests their problem-solving skills. 148 00:11:51,520 --> 00:11:53,400 It might look simple, but this 149 00:11:53,400 --> 00:11:56,280 is something they would never see in the wild. 150 00:11:56,280 --> 00:11:59,360 So they must be innovative and use their imagination 151 00:11:59,360 --> 00:12:01,200 to figure this out. 152 00:12:05,560 --> 00:12:07,800 He's trying a bit of everything. 153 00:12:07,800 --> 00:12:10,040 Yeah. I know leopard or hyenas, they bite and bite, 154 00:12:10,040 --> 00:12:13,280 they will bash it, but didn't have the brains to actually think, 155 00:12:13,280 --> 00:12:15,120 "There's a gadget holding this closed - 156 00:12:15,120 --> 00:12:17,360 "I've got to move it out the way." 157 00:12:17,360 --> 00:12:19,400 There you go. There you go. You've got it. 158 00:12:19,400 --> 00:12:21,040 Good for you. 159 00:12:23,240 --> 00:12:26,280 Well, I'll be blowed. He's actually done it. Yeah. 160 00:12:29,400 --> 00:12:31,440 Well done, sir. 161 00:12:35,800 --> 00:12:39,280 Both Julius and Stompy solved this first challenge. 162 00:12:41,080 --> 00:12:44,480 But what happens when it becomes more complicated? 163 00:12:48,640 --> 00:12:51,920 A lot of animals have difficulty, once they figure out how to achieve 164 00:12:51,920 --> 00:12:54,520 a goal in one way, they get kind of stuck on that solution. 165 00:12:54,520 --> 00:12:56,640 So we're going to see if honey badgers 166 00:12:56,640 --> 00:12:58,200 are able to change their thinking 167 00:12:58,200 --> 00:13:00,800 and not get stuck on that bar solution. 168 00:13:03,840 --> 00:13:08,160 This second challenge tests how adaptable their brains can be. 169 00:13:11,000 --> 00:13:13,600 There's a clear container inside that the food will be in, 170 00:13:13,600 --> 00:13:15,640 but it's out of reach of the honey badger. 171 00:13:15,640 --> 00:13:19,120 So they have to figure out to pull the string to get the food. 172 00:13:19,120 --> 00:13:22,480 Do you think they'll be able to solve this one, as well? 173 00:13:22,480 --> 00:13:25,360 My experience with it over the years is there's nothing he wouldn't 174 00:13:25,360 --> 00:13:27,200 really solve, unless it's a lock and a key. 175 00:13:29,440 --> 00:13:33,520 In the wild, honey badgers eat up to 60 different species. 176 00:13:35,560 --> 00:13:39,000 To hunt this range of food, they have to think flexibly. 177 00:13:41,760 --> 00:13:44,280 He's worked that out! 178 00:13:44,280 --> 00:13:46,480 Isn't that wonderful, hey? 179 00:13:46,480 --> 00:13:48,680 You can't help but love these things. 180 00:13:48,680 --> 00:13:50,600 Doesn't matter what they do to you! 181 00:13:53,600 --> 00:13:56,480 So far, the honey badgers have shown problem-solving 182 00:13:56,480 --> 00:13:58,280 skills and adaptability. 183 00:13:59,920 --> 00:14:01,760 But in the third and final test, 184 00:14:01,760 --> 00:14:04,200 can they do something that would mark 185 00:14:04,200 --> 00:14:07,640 them as one of the most intelligent animals on the planet - 186 00:14:07,640 --> 00:14:09,280 use tools? 187 00:14:11,120 --> 00:14:12,920 We've hung the box from a tree, 188 00:14:12,920 --> 00:14:15,560 so the honey badger can't reach it from the top. 189 00:14:15,560 --> 00:14:17,600 That can't reach it from the bottom. 190 00:14:17,600 --> 00:14:20,640 The only way they can reach it is by dragging either a tyre 191 00:14:20,640 --> 00:14:24,720 or their cage under it, so that they can then step up 192 00:14:24,720 --> 00:14:27,560 and reach the food that is inside. 193 00:14:31,400 --> 00:14:34,240 If, in fact, honey badgers can use tools, this puts them 194 00:14:34,240 --> 00:14:36,880 up there with some of the smartest animals in the animal kingdom, 195 00:14:36,880 --> 00:14:39,320 like chimpanzees or elephants. 196 00:14:39,320 --> 00:14:41,680 So it would be really exciting. 197 00:14:41,680 --> 00:14:46,160 Every single one has had that ability to escape, to take an object 198 00:14:46,160 --> 00:14:48,280 to the side of the wall and climb out. 199 00:14:48,280 --> 00:14:51,120 So, definitely, the potential is there. 200 00:14:53,840 --> 00:14:55,360 So he seems to be just jumping 201 00:14:55,360 --> 00:14:57,440 and trying to get to the box, but not making 202 00:14:57,440 --> 00:15:00,840 that connection that he needs to bring the crate or the tyre over. 203 00:15:00,840 --> 00:15:02,160 He really wants it 204 00:15:02,160 --> 00:15:04,720 but he just can't seem to figure out how to get to it. 205 00:15:06,760 --> 00:15:08,560 You see, he knows there's something there. 206 00:15:08,560 --> 00:15:10,560 Mmm, he's looking at it... 207 00:15:17,920 --> 00:15:20,040 He pushed his crate closer to the box 208 00:15:20,040 --> 00:15:22,560 so that he could then climb on top of the crate 209 00:15:22,560 --> 00:15:24,960 and get to the box, which indicates tool use, 210 00:15:24,960 --> 00:15:26,760 and is really exciting. 211 00:15:26,760 --> 00:15:28,240 Stunning. 212 00:15:28,240 --> 00:15:30,120 That is pretty cool, I must say. 213 00:15:36,600 --> 00:15:38,960 Giving them this puzzle box is confirming what we've long 214 00:15:38,960 --> 00:15:41,840 suspected - that honey badgers are very good at solving problems, 215 00:15:41,840 --> 00:15:44,520 that they're very exploratory and adaptable. 216 00:15:44,520 --> 00:15:47,400 From what we've seen, they're up there with the top innovators 217 00:15:47,400 --> 00:15:49,400 in the animal kingdom. 218 00:15:49,400 --> 00:15:54,080 It's this intelligence - often misread as calculated and cunning - 219 00:15:54,080 --> 00:15:57,000 that gives these animals an edge in the wild. 220 00:16:10,240 --> 00:16:12,880 Back in Stoat City, it's May. 221 00:16:15,080 --> 00:16:18,840 Bandita has given birth, but her kits have remained hidden... 222 00:16:21,880 --> 00:16:24,400 ..until one morning, when she gave Rob 223 00:16:24,400 --> 00:16:27,000 the surprise of his life. 224 00:16:27,000 --> 00:16:30,040 I'll never forget the day when we first got the footage 225 00:16:30,040 --> 00:16:31,840 of the kits emerging. 226 00:16:37,520 --> 00:16:41,400 One by one, the kits came out and then we realised 227 00:16:41,400 --> 00:16:42,680 there was four kits. 228 00:16:42,680 --> 00:16:45,040 Incredible things, because they were 229 00:16:45,040 --> 00:16:47,280 actually a really strange colour. 230 00:16:47,280 --> 00:16:50,120 They were a white, mottled-y colour. 231 00:16:50,120 --> 00:16:51,760 This is really rare. 232 00:16:51,760 --> 00:16:54,800 There's very few records of this right the way across the world. 233 00:16:54,800 --> 00:16:56,520 So we're absolutely delighted 234 00:16:56,520 --> 00:16:59,120 that we've got extra special stoat kits to watch. 235 00:17:00,920 --> 00:17:03,960 Some stoats turn white - or ermine - in the winter 236 00:17:03,960 --> 00:17:06,680 to camouflage themselves against the snow. 237 00:17:06,680 --> 00:17:10,640 These kits were born in a cold spell, which could be the cause 238 00:17:10,640 --> 00:17:12,560 of their unusual colour. 239 00:17:15,440 --> 00:17:18,600 But their first outing doesn't go to plan. 240 00:17:18,600 --> 00:17:23,640 Inexperienced mum Bandita quickly loses control of her kits. 241 00:17:25,080 --> 00:17:27,720 One falls over the edge of a wall. 242 00:17:29,560 --> 00:17:31,360 Followed by another. 243 00:17:39,400 --> 00:17:41,720 Bandita appears to panic... 244 00:17:45,880 --> 00:17:49,640 ..and instinctively moves her kits away from this danger. 245 00:17:54,720 --> 00:17:56,720 She leaves Stoat City, and Rob 246 00:17:56,720 --> 00:18:00,000 spots her running into an elm tree down the valley. 247 00:18:03,640 --> 00:18:05,920 For now, the kits seem OK. 248 00:18:09,360 --> 00:18:13,440 But this move has unwittingly led her into further peril. 249 00:18:15,080 --> 00:18:17,480 This nest site could jeopardise the safety 250 00:18:17,480 --> 00:18:19,520 of her vulnerable youngsters. 251 00:18:21,280 --> 00:18:22,760 She's got problems here. 252 00:18:22,760 --> 00:18:24,200 She's next to the road. 253 00:18:24,200 --> 00:18:27,280 And this is also the favourite tree for a family of tawny owls. 254 00:18:27,280 --> 00:18:29,920 The kits are in real danger here of predation. 255 00:18:29,920 --> 00:18:31,960 Not so much her - she's quite feisty - 256 00:18:31,960 --> 00:18:34,640 but the little kits walking around, they're quite pale, 257 00:18:34,640 --> 00:18:36,760 and they really stand out in the dark. 258 00:18:40,080 --> 00:18:41,280 This is the road just here. 259 00:18:41,280 --> 00:18:44,480 So instead of running up the dale side, which is the sensible thing 260 00:18:44,480 --> 00:18:46,520 to do, she actually goes out onto the road, 261 00:18:46,520 --> 00:18:48,360 which is really dangerous. 262 00:18:52,840 --> 00:18:56,440 To hunt in her usual territory, Bandita risks everything, 263 00:18:56,440 --> 00:18:59,320 travelling 100 metres along the road. 264 00:19:10,080 --> 00:19:12,720 I've watched her coming up the hill, and a van comes down, 265 00:19:12,720 --> 00:19:14,560 and you're just like, "Oh!" 266 00:19:14,560 --> 00:19:17,760 It's just... You're just hoping she spots it. 267 00:19:17,760 --> 00:19:20,400 You know, hoping they're all going to be OK. 268 00:19:25,920 --> 00:19:28,360 Will Bandita be able to keep her kits safe 269 00:19:28,360 --> 00:19:30,240 in this perilous location? 270 00:19:34,680 --> 00:19:38,560 Moving kits from nest to nest is one of the mustelids' survival 271 00:19:38,560 --> 00:19:41,160 strategies, but it can involve risks. 272 00:19:43,200 --> 00:19:46,600 During the journey, kits can become separated from their mum. 273 00:19:49,600 --> 00:19:51,840 Weasels - the smallest of all mustelids, 274 00:19:51,840 --> 00:19:53,720 and a close relative of the stoat - 275 00:19:53,720 --> 00:19:55,600 are particularly vulnerable. 276 00:20:00,760 --> 00:20:04,200 A baby weasel that was lost during a nest move 277 00:20:04,200 --> 00:20:06,360 has been spotted and rescued. 278 00:20:06,360 --> 00:20:08,400 She's now in Rob's care. 279 00:20:10,640 --> 00:20:12,240 This is quite incredible here. 280 00:20:12,240 --> 00:20:13,880 We've got a tiny little female. 281 00:20:13,880 --> 00:20:16,080 This is about three weeks old. 282 00:20:16,080 --> 00:20:19,360 Tiny little tail, which obviously tells us it's a weasel 283 00:20:19,360 --> 00:20:21,720 rather than a stoat. 284 00:20:21,720 --> 00:20:24,440 At this stage, we call them fingerlings, because they are 285 00:20:24,440 --> 00:20:26,680 literally the size of your finger. 286 00:20:29,840 --> 00:20:33,880 By following this orphaned weasel, we can see how she grows up 287 00:20:33,880 --> 00:20:35,880 to be a tiny but mighty predator. 288 00:20:40,440 --> 00:20:42,760 Rob names the weasel Twiz. 289 00:20:44,400 --> 00:20:47,480 The actual name weasel - "weasel out of a situation" - 290 00:20:47,480 --> 00:20:49,360 it has such negative connotations. 291 00:20:49,360 --> 00:20:52,240 But when you see such a sweet little baby weasel like this, 292 00:20:52,240 --> 00:20:55,960 it's hard to imagine why you had...negative, in any way. 293 00:20:55,960 --> 00:20:58,360 They're absolutely stunning little mammals. 294 00:21:02,400 --> 00:21:03,880 A week has passed. 295 00:21:03,880 --> 00:21:06,840 In these early days, weight gain is vital. 296 00:21:06,840 --> 00:21:10,120 And last week, Twiz weighed just 12g. 297 00:21:13,200 --> 00:21:15,760 These tiny animals have an extremely 298 00:21:15,760 --> 00:21:18,880 high metabolism and have to feed every few hours. 299 00:21:21,120 --> 00:21:23,960 That's incredible - she's actually 30g now, 300 00:21:23,960 --> 00:21:27,600 so she's put on more than double her weight in one week. 301 00:21:27,600 --> 00:21:29,320 Absolutely brilliant. 302 00:21:31,680 --> 00:21:35,520 Her fur's grown, her eyes are just about to open any day now. 303 00:21:35,520 --> 00:21:37,320 Her feet are getting more useful. 304 00:21:37,320 --> 00:21:39,800 She's able to move around a lot more. 305 00:21:39,800 --> 00:21:43,440 Teeth are coming through now, and she's eating meat. 306 00:21:43,440 --> 00:21:45,000 So she's on high-protein diet 307 00:21:45,000 --> 00:21:47,760 so she's going to grow really quickly now. 308 00:21:47,760 --> 00:21:50,760 Even though her eyes are still closed, her senses 309 00:21:50,760 --> 00:21:52,080 are absolutely astonishing. 310 00:21:52,080 --> 00:21:56,600 She's able to use her sense of smell and find the food. 311 00:21:58,880 --> 00:22:02,560 This incredible smelling ability is one of this animal family's 312 00:22:02,560 --> 00:22:04,600 most valued skills. 313 00:22:12,720 --> 00:22:16,560 And one uses this to its fullest potential - 314 00:22:16,560 --> 00:22:18,520 the wolverine. 315 00:22:29,800 --> 00:22:33,640 They're found across the Arctic regions of the northern hemisphere. 316 00:22:33,640 --> 00:22:37,480 And every part of them was built for the cold. 317 00:22:41,880 --> 00:22:46,240 They travel up to 20 miles a day, foraging across the wilderness. 318 00:22:51,880 --> 00:22:55,280 Even sniffing out prey from deep under the snow. 319 00:22:58,840 --> 00:23:01,240 But how are they able to do this? 320 00:23:08,600 --> 00:23:12,040 Dr Deborah Bird from the University of California studies 321 00:23:12,040 --> 00:23:14,880 how carnivores smell. 322 00:23:14,880 --> 00:23:18,320 She believes that an animal's scenting capacity is linked 323 00:23:18,320 --> 00:23:22,240 to a structure in their skull known as the cribriform plate. 324 00:23:22,240 --> 00:23:26,680 The cribriform plate is an imprint of an animal's sense of smell. 325 00:23:26,680 --> 00:23:29,240 So the more nerves dedicated to smell, 326 00:23:29,240 --> 00:23:31,400 the larger the cribriform plate. 327 00:23:34,400 --> 00:23:38,400 The cribriform plate is located between the nasal cavity 328 00:23:38,400 --> 00:23:39,840 and the brain. 329 00:23:41,480 --> 00:23:45,120 It's a bony, sieve-like structure with holes for nerve fibres 330 00:23:45,120 --> 00:23:46,960 to pass through. 331 00:23:49,200 --> 00:23:53,640 These nerve fibres carry scent signals from the air to the brain. 332 00:23:56,320 --> 00:24:00,000 The bigger the cribriform plate and the bigger the holes, 333 00:24:00,000 --> 00:24:03,600 the more scent information can travel to the brain. 334 00:24:05,320 --> 00:24:08,960 So with a wolverine, it's quite large for its body size. 335 00:24:08,960 --> 00:24:12,840 That suggests that the wolverine has a really keen sense of smell. 336 00:24:12,840 --> 00:24:16,160 That's a hypothesis, and it needs to be tested by looking 337 00:24:16,160 --> 00:24:18,640 at its behaviour. 338 00:24:18,640 --> 00:24:21,280 For the first time, the wolverine's 339 00:24:21,280 --> 00:24:23,920 sense of smell will be put to the test. 340 00:24:29,680 --> 00:24:31,640 Sweden. 341 00:24:31,640 --> 00:24:34,480 Nordens Ark Zoo on the west coast 342 00:24:34,480 --> 00:24:37,120 is home to six native wolverines. 343 00:24:42,000 --> 00:24:45,840 Dr Marta Gasci has studied the smelling capabilities of dogs 344 00:24:45,840 --> 00:24:50,120 and wolves, and now she's turned her attention to wolverines. 345 00:24:52,160 --> 00:24:54,400 This is a rather simple experiment. 346 00:24:54,400 --> 00:24:58,040 There are plastic pots under all the ceramic pots, 347 00:24:58,040 --> 00:25:00,080 but only one is baited. 348 00:25:02,760 --> 00:25:05,880 Meat is placed in just one of the four plastic pots 349 00:25:05,880 --> 00:25:09,240 and the wolverine has to sniff out where it is. 350 00:25:11,000 --> 00:25:13,480 The test has three levels of difficulty. 351 00:25:13,480 --> 00:25:17,400 In the first, the plastic pots have no lid on them. 352 00:25:18,960 --> 00:25:23,040 In the second level, the pots have three holes in the lid. 353 00:25:23,040 --> 00:25:26,880 And finally, in the last level, there is just one small hole 354 00:25:26,880 --> 00:25:29,280 for the scent of the meat to escape. 355 00:25:36,920 --> 00:25:40,160 With their relatively large cribriform plates, 356 00:25:40,160 --> 00:25:43,160 this first level with no lid should be straightforward 357 00:25:43,160 --> 00:25:44,960 for the wolverines. 358 00:25:52,680 --> 00:25:56,040 Within minutes, they can locate the meat in the open pot. 359 00:25:57,360 --> 00:25:59,160 OK, let's check that one. 360 00:26:03,880 --> 00:26:07,720 The next challenge is the pot with three holes in the lid. 361 00:26:19,000 --> 00:26:21,760 Once again, the wolverines manage to locate the food 362 00:26:21,760 --> 00:26:24,800 in less than a minute in almost every trial. 363 00:26:32,040 --> 00:26:35,960 On the experiment's third and final level, the lid of the plastic pot 364 00:26:35,960 --> 00:26:37,800 has just one single hole. 365 00:26:49,800 --> 00:26:53,040 This task is so difficult that it triggers the wolverines 366 00:26:53,040 --> 00:26:55,920 to start using a deep blowing technique. 367 00:26:57,480 --> 00:27:00,160 WOLVERINE BLOWS OUT 368 00:27:07,520 --> 00:27:10,480 They breathe air in through their mouth and force it out 369 00:27:10,480 --> 00:27:12,880 through their nose towards the meat. 370 00:27:14,600 --> 00:27:17,600 This warms and disturbs the odour particles, causing the smell 371 00:27:17,600 --> 00:27:19,440 to become stronger. 372 00:27:25,280 --> 00:27:29,040 Even though barely any scent is escaping from the pot, 373 00:27:29,040 --> 00:27:32,040 the wolverines can now locate the food. 374 00:27:40,800 --> 00:27:45,840 You can imagine how difficult it could be to smell out the meat 375 00:27:45,840 --> 00:27:47,680 through this tiny hole. 376 00:27:47,680 --> 00:27:49,880 And that's what the wolverines did. 377 00:27:51,680 --> 00:27:54,600 The wolverine's sense of smell has never been tested 378 00:27:54,600 --> 00:27:56,600 like this before. 379 00:28:00,560 --> 00:28:04,360 The results suggest that a large cribriform plate could indeed 380 00:28:04,360 --> 00:28:08,000 be behind an animal's heightened scenting ability. 381 00:28:12,240 --> 00:28:15,880 This ability means that wolverines and other mustelids 382 00:28:15,880 --> 00:28:19,360 can find the food they need to survive, wherever it is. 383 00:28:20,560 --> 00:28:23,200 It's key to their success in the wild. 384 00:28:42,600 --> 00:28:45,560 Orphaned weasel Twiz is now five weeks old. 385 00:28:47,200 --> 00:28:49,920 Her eyes have opened, her hearing is becoming more acute, 386 00:28:49,920 --> 00:28:52,280 and she's much more active. 387 00:28:56,520 --> 00:28:59,360 In the wild, Twiz would be playing with the rest of her litter. 388 00:28:59,360 --> 00:29:01,960 So Rob has to take over this role. 389 00:29:04,200 --> 00:29:07,120 Play is how a weasel would learn how to fight and to hunt. 390 00:29:08,920 --> 00:29:11,560 They use all four limbs to grip the prey items, 391 00:29:11,560 --> 00:29:14,680 deliver a real powerful bite, then, to the back of the neck, 392 00:29:14,680 --> 00:29:16,960 but very gentle at this stage. 393 00:29:16,960 --> 00:29:19,920 She's only small still, so it's fabulous to see 394 00:29:19,920 --> 00:29:22,320 that she's got this instinct in her already. 395 00:29:22,320 --> 00:29:24,120 TWIZ CHITTERS 396 00:29:24,120 --> 00:29:26,840 The little chittering, this is like a contact call. 397 00:29:26,840 --> 00:29:29,440 I've heard this in the wild with wild weasels lots of times, 398 00:29:29,440 --> 00:29:31,880 and it's... To me, it's one of the most 399 00:29:31,880 --> 00:29:33,720 beautiful sounds that there actually is. 400 00:29:33,720 --> 00:29:35,960 TWIZ CHITTERS 401 00:29:35,960 --> 00:29:39,200 Twiz must start strengthening her muscles, to improve her agility. 402 00:29:41,760 --> 00:29:43,840 And this needs to be done indoors. 403 00:29:45,520 --> 00:29:48,840 We're going to test her strength, agility, in a safe environment. 404 00:29:52,680 --> 00:29:55,880 Rob wants to see if Twiz is brave enough to explore, 405 00:29:55,880 --> 00:29:59,160 but also cautious enough to hide from any danger. 406 00:30:00,480 --> 00:30:02,120 Got to be always close to cover, 407 00:30:02,120 --> 00:30:05,200 because they're vulnerable from attack from other predators. 408 00:30:05,200 --> 00:30:07,840 She's heading for cover when she's really unsure, 409 00:30:07,840 --> 00:30:09,880 which is a great sign, because she needs to be 410 00:30:09,880 --> 00:30:12,920 absolutely on the ball when she's out in the wild. 411 00:30:18,080 --> 00:30:21,840 At this age, wild weasel kits would go on day trips 412 00:30:21,840 --> 00:30:26,520 with their mum, who would show them how to hunt prey... 413 00:30:26,520 --> 00:30:31,360 ..and Rob's got just the thing to help Twiz. 414 00:30:33,200 --> 00:30:36,280 It'll be an easy target. ROB CHUCKLES 415 00:30:36,280 --> 00:30:39,080 In a matter of weeks, they'll actually be independent 416 00:30:39,080 --> 00:30:40,800 and hunting for themselves. 417 00:30:42,560 --> 00:30:45,440 Weasels eat anything from birds to voles, 418 00:30:45,440 --> 00:30:47,760 so they need to climb and tunnel. 419 00:30:50,840 --> 00:30:53,560 She's just coming back for a little bit of reassurance. 420 00:30:53,560 --> 00:30:56,600 That's what they'll be doing in the wild, going back to their mother, 421 00:30:56,600 --> 00:30:58,600 and she'll go off again, adventuring. 422 00:30:58,600 --> 00:31:00,880 She's showing great signs. 423 00:31:00,880 --> 00:31:02,480 Yeah, it's great to see. 424 00:31:11,520 --> 00:31:15,400 Stoats and weasels are at their most vulnerable when they're young. 425 00:31:17,280 --> 00:31:19,960 Their early weeks are full of challenges 426 00:31:19,960 --> 00:31:21,840 and important life lessons. 427 00:31:21,840 --> 00:31:24,200 BIRDS CHIRP 428 00:31:24,200 --> 00:31:26,240 It's now June. 429 00:31:34,040 --> 00:31:38,040 Bandita has brought all four kits back to Stoat City... 430 00:31:40,800 --> 00:31:45,120 ..and they've made their home in one of Rob's specially rigged nests. 431 00:31:47,560 --> 00:31:49,800 The kits are nine weeks old, 432 00:31:49,800 --> 00:31:53,040 but, worryingly, one clearly isn't thriving. 433 00:31:58,560 --> 00:32:01,400 Having a runt in the litter is common. 434 00:32:01,400 --> 00:32:04,360 If they are born smaller, they struggle to compete 435 00:32:04,360 --> 00:32:07,440 with their bigger and stronger siblings for food... 436 00:32:08,840 --> 00:32:11,880 ..and sometimes the struggle proves too much. 437 00:32:14,320 --> 00:32:16,640 Unfortunately, it passed away. 438 00:32:16,640 --> 00:32:20,080 It's a difficult thing to watch. It was quite a sad day, really, 439 00:32:20,080 --> 00:32:24,120 that you realise we've lost one of these really special little stoats. 440 00:32:33,280 --> 00:32:38,760 Despite this sad loss, Bandita still has three kits to care for. 441 00:32:43,640 --> 00:32:46,160 Their appetites are enormous. 442 00:32:46,160 --> 00:32:50,120 She has to feed them half of their body weight every day. 443 00:32:54,240 --> 00:32:56,000 It's a difficult job 444 00:32:56,000 --> 00:32:58,640 and it's about to get even harder 445 00:32:58,640 --> 00:33:02,320 as Stoat City is facing an invasion. 446 00:33:08,800 --> 00:33:10,680 Rats! 447 00:33:15,840 --> 00:33:18,360 The archenemy of stoats. 448 00:33:20,360 --> 00:33:23,080 Not only do they steal food from Bandita, 449 00:33:23,080 --> 00:33:27,480 but a big, dangerous male has been trying to get into her nest. 450 00:33:39,200 --> 00:33:43,320 Rob has an idea to make sure there'll be enough food for all. 451 00:33:44,560 --> 00:33:47,240 We need to put some food where rats cannot get. 452 00:33:47,240 --> 00:33:49,840 So we've chosen a children's climbing frame 453 00:33:49,840 --> 00:33:51,600 and put a high wire four metres up. 454 00:33:51,600 --> 00:33:54,120 So this is a place where the stoats can get to, 455 00:33:54,120 --> 00:33:56,800 but the rats will really struggle to get right up here. 456 00:33:56,800 --> 00:33:59,600 Rats will climb trees, rats will go into birds' nests, 457 00:33:59,600 --> 00:34:02,880 but this is going to be too much for the average rat, going up there. 458 00:34:02,880 --> 00:34:05,320 We've got the whole area rigged with cameras, as well. 459 00:34:05,320 --> 00:34:06,760 So we'll be able to see 460 00:34:06,760 --> 00:34:09,320 over the next couple of days how she gets on. 461 00:34:13,120 --> 00:34:15,840 As night falls, Bandita appears, 462 00:34:15,840 --> 00:34:18,240 and her exceptional sense of smell 463 00:34:18,240 --> 00:34:20,920 draws her straight to the climbing frame. 464 00:34:29,880 --> 00:34:32,720 Her tail is half the length of her body 465 00:34:32,720 --> 00:34:35,280 and helps her keep balance when up high. 466 00:34:40,440 --> 00:34:43,680 Bandita leaps vast distances - 467 00:34:43,680 --> 00:34:47,560 over ten times her body length - 468 00:34:47,560 --> 00:34:51,600 bravely pushing herself to the limit to get food back to her kits. 469 00:35:02,160 --> 00:35:04,000 For such a small animal, 470 00:35:04,000 --> 00:35:06,800 this jumping ability is astounding. 471 00:35:11,480 --> 00:35:16,400 Once again, Bandita has overcome adversity to provide for her family. 472 00:35:27,560 --> 00:35:30,200 The saying "to weasel out of something" 473 00:35:30,200 --> 00:35:34,000 owes its origin to this animal family's extraordinary agility. 474 00:35:38,120 --> 00:35:41,640 Many of the mustelids are known for their acrobatics. 475 00:35:43,680 --> 00:35:47,080 North America. 476 00:35:47,080 --> 00:35:52,680 Home to one of the most arboreal and agile mustelids of all - 477 00:35:52,680 --> 00:35:55,320 the American pine marten. 478 00:35:57,440 --> 00:36:00,480 They're built entirely for life in the trees. 479 00:36:04,360 --> 00:36:07,200 Their long, bushy tail keeps them balanced 480 00:36:07,200 --> 00:36:09,640 when jumping from branch to branch... 481 00:36:11,280 --> 00:36:16,080 ..and their razor-sharp claws grip tightly into the bark of trees. 482 00:36:23,200 --> 00:36:25,240 They have to hunt up here, too - 483 00:36:25,240 --> 00:36:29,560 moving swiftly through the branches in pursuit of their prey. 484 00:36:32,560 --> 00:36:36,840 In the springtime, they raid birds' nest for eggs. 485 00:36:39,880 --> 00:36:43,200 An easy job with this stationary target. 486 00:36:44,720 --> 00:36:47,000 But for the rest of the year, 487 00:36:47,000 --> 00:36:50,080 their prey is on the move. 488 00:37:04,400 --> 00:37:06,680 Their claws are their secret weapon. 489 00:37:06,680 --> 00:37:09,800 Not only do they help them latch on to tree trunks, 490 00:37:09,800 --> 00:37:12,360 but they can also partially retract, 491 00:37:12,360 --> 00:37:15,000 so the marten can move easily on the ground 492 00:37:15,000 --> 00:37:17,440 when an appetising meal turns up. 493 00:37:29,640 --> 00:37:31,360 Mustelids are so versatile 494 00:37:31,360 --> 00:37:34,920 that they can use their agility in many environments. 495 00:37:36,440 --> 00:37:40,640 One species is particularly adept at manoeuvres below the ground. 496 00:37:41,880 --> 00:37:43,640 The ferret. 497 00:37:49,000 --> 00:37:52,600 They were domesticated from the European polecat 498 00:37:52,600 --> 00:37:54,200 over 2,000 years ago. 499 00:37:55,240 --> 00:37:59,520 In the wild, these animals hunt in tight and twisty burrows 500 00:37:59,520 --> 00:38:02,960 and their entire body can bend 180 degrees - 501 00:38:02,960 --> 00:38:05,600 both vertically and horizontally. 502 00:38:08,440 --> 00:38:11,360 But how were they able to do this? 503 00:38:16,480 --> 00:38:18,200 Ohio, in the USA. 504 00:38:21,040 --> 00:38:26,320 Dr Angela Horner is the world's leading expert in ferret locomotion. 505 00:38:30,560 --> 00:38:32,400 Ferrets are really neat. 506 00:38:32,400 --> 00:38:35,880 It's almost as though you have an animal in liquid form. 507 00:38:35,880 --> 00:38:38,520 They have a really well-adapted body design 508 00:38:38,520 --> 00:38:42,400 to move rapidly through a tunnel and change direction quickly. 509 00:38:42,400 --> 00:38:46,040 And it has to be small enough to enter a tunnel, 510 00:38:46,040 --> 00:38:48,880 but large and powerful enough to overpower something 511 00:38:48,880 --> 00:38:52,040 when it encounters that in the tunnel. 512 00:38:52,040 --> 00:38:55,320 This unique body shape is crucial for an animal 513 00:38:55,320 --> 00:38:58,600 that spends 90% of its time underground, 514 00:38:58,600 --> 00:39:02,480 but being subterranean makes studying ferrets hard. 515 00:39:04,280 --> 00:39:07,320 This Perspex tunnel will allow Angela to see 516 00:39:07,320 --> 00:39:10,880 how their bodies transform as they enter a burrow. 517 00:39:10,880 --> 00:39:13,440 So what I'm looking at here is a special set-up 518 00:39:13,440 --> 00:39:16,760 designed to let me see what's happening during the transition 519 00:39:16,760 --> 00:39:19,720 from above-ground conditions to below-ground conditions. 520 00:39:19,720 --> 00:39:22,800 We haven't really seen yet how this is happening 521 00:39:22,800 --> 00:39:24,760 from the animal's perspective, 522 00:39:24,760 --> 00:39:27,360 so I'm really excited to try this out. 523 00:39:28,800 --> 00:39:31,560 By filming the ferret in slow motion, 524 00:39:31,560 --> 00:39:34,920 Angela can see exactly what the ferret is doing. 525 00:39:39,560 --> 00:39:41,640 When they're moving around above ground, 526 00:39:41,640 --> 00:39:44,480 they have an arched-back posture. 527 00:39:44,480 --> 00:39:46,320 And as they enter a tunnel, 528 00:39:46,320 --> 00:39:49,720 they seamlessly lower that posture in their back 529 00:39:49,720 --> 00:39:52,200 until their spine is stretched out. 530 00:39:54,440 --> 00:39:56,720 This flexibility in their spine 531 00:39:56,720 --> 00:39:59,440 is due to a unique set of back vertebrae. 532 00:40:01,280 --> 00:40:04,600 In other animals, protrusions, known as "processes", 533 00:40:04,600 --> 00:40:08,080 on each segment of the spine, stop it from moving too far. 534 00:40:11,120 --> 00:40:13,800 In ferrets, these processes are thinner, 535 00:40:13,800 --> 00:40:16,120 creating flexibility and movement. 536 00:40:20,040 --> 00:40:23,200 So their spine can stretch out when they go underground, 537 00:40:23,200 --> 00:40:25,720 making their body 30% longer. 538 00:40:31,280 --> 00:40:34,880 This footage shows how easily the ferrets can transition 539 00:40:34,880 --> 00:40:36,880 from above to below ground. 540 00:40:38,520 --> 00:40:40,760 But these animals are predators. 541 00:40:40,760 --> 00:40:44,440 So what impact does this manoeuvre have on the ferret's speed? 542 00:40:47,000 --> 00:40:50,400 The black-and-white card helps Angela determine 543 00:40:50,400 --> 00:40:53,840 how fast the ferrets are travelling across a set distance. 544 00:40:55,200 --> 00:40:57,000 When the footage is lined up, 545 00:40:57,000 --> 00:41:00,280 it reveals something completely unexpected. 546 00:41:02,480 --> 00:41:06,360 The ferret barely loses any speed at all when running underground. 547 00:41:11,760 --> 00:41:15,920 Their shorter-than-average limbs allow them to still be able to move 548 00:41:15,920 --> 00:41:18,440 very well and they aren't restricted 549 00:41:18,440 --> 00:41:21,160 in the limb movement in that position. 550 00:41:28,320 --> 00:41:30,000 In most carnivores, 551 00:41:30,000 --> 00:41:33,000 the legs and body are about the same length. 552 00:41:33,000 --> 00:41:36,280 But in burrowing mustelids, like the ferret, 553 00:41:36,280 --> 00:41:39,280 their legs are only half the length of their body. 554 00:41:43,720 --> 00:41:46,400 This means they can run in enclosed spaces 555 00:41:46,400 --> 00:41:49,200 without tripping over their own limbs. 556 00:41:52,600 --> 00:41:53,880 Their limbs have to 557 00:41:53,880 --> 00:41:55,520 become more crouched 558 00:41:55,520 --> 00:41:57,080 to get into that position. 559 00:41:57,080 --> 00:41:58,960 But they can manage it just fine. 560 00:41:58,960 --> 00:42:00,200 In fact, they do it so well 561 00:42:00,200 --> 00:42:01,600 that they barely decrease speed 562 00:42:01,600 --> 00:42:03,240 when they're making that transition 563 00:42:03,240 --> 00:42:04,880 from above ground to underground, 564 00:42:04,880 --> 00:42:06,520 and that's incredible. 565 00:42:09,960 --> 00:42:13,600 The ability to shift so seamlessly between these environments 566 00:42:13,600 --> 00:42:15,440 is just one of the remarkable ways 567 00:42:15,440 --> 00:42:18,880 that mustelids have refined their agility to catch prey. 568 00:42:34,600 --> 00:42:36,440 Back at Rob's house, 569 00:42:36,440 --> 00:42:39,200 Bandita's kits are now ten weeks old. 570 00:42:41,160 --> 00:42:45,280 So far, most of their days have been spent safely hidden away. 571 00:42:46,720 --> 00:42:51,080 But now they're ready for a trip into Stoat City. 572 00:42:51,080 --> 00:42:53,840 We've named them Snap, Crackle and Pop. 573 00:42:53,840 --> 00:42:56,240 Snap's the one, he seems to be a little bit more 574 00:42:56,240 --> 00:42:57,880 adventurous on his own. 575 00:42:59,520 --> 00:43:03,000 Pop's the one with the little panda-looking eyes. 576 00:43:03,000 --> 00:43:06,240 He's a little bit of a mummy's boy. He's always close to Bandita. 577 00:43:07,960 --> 00:43:10,880 Crackle's the female and she's substantially smaller, 578 00:43:10,880 --> 00:43:13,320 but she's got some real attitude about her. 579 00:43:13,320 --> 00:43:17,640 She really holds her own against the boys, fighting, rolling, playing. 580 00:43:19,360 --> 00:43:22,160 Bandita will need to watch over the kits 581 00:43:22,160 --> 00:43:24,920 every moment of this day trip. 582 00:43:24,920 --> 00:43:27,640 It's a big garden and they could get lost. 583 00:43:32,600 --> 00:43:34,440 So to keep them close, 584 00:43:34,440 --> 00:43:37,320 she makes a special chitter contact call. 585 00:43:37,320 --> 00:43:39,160 BANDITA CHITTERS 586 00:43:45,640 --> 00:43:48,720 It's time for a tour of her territory. 587 00:43:54,160 --> 00:43:58,400 She shows them the key places they can sleep and hunt. 588 00:44:05,200 --> 00:44:08,840 Over the next few weeks, they move on to the next lesson. 589 00:44:08,840 --> 00:44:11,240 Bandita needs to teach them 590 00:44:11,240 --> 00:44:14,120 how to hone their chasing and fighting skills. 591 00:44:14,120 --> 00:44:15,720 This is really important 592 00:44:15,720 --> 00:44:18,520 because this is teaching the kits how to hunt 593 00:44:18,520 --> 00:44:21,200 and they will be hunting dangerous animals. 594 00:44:31,520 --> 00:44:35,800 And it looks like these lessons are also lots of fun! 595 00:44:37,160 --> 00:44:39,480 The trampoline's a great area for the stoats. 596 00:44:39,480 --> 00:44:41,480 They're loving being on there. 597 00:44:47,800 --> 00:44:51,040 So they're learning new tricks on their pouncing, 598 00:44:51,040 --> 00:44:54,080 and they also just love the texture of the trampoline. 599 00:44:54,080 --> 00:44:56,360 They climb on and they just slide on, 600 00:44:56,360 --> 00:44:59,120 pulling themselves along with their front legs. 601 00:45:11,120 --> 00:45:14,200 After six weeks of intensive training, 602 00:45:14,200 --> 00:45:17,960 Bandita's biggest kit, Snap, is ready to go 603 00:45:17,960 --> 00:45:20,120 on a special hunting mission. 604 00:45:21,680 --> 00:45:26,880 But Rob's garden is also home to other predators. 605 00:45:26,880 --> 00:45:29,640 They compete with the stoats for food, 606 00:45:29,640 --> 00:45:32,680 but they could also prey on the young kits. 607 00:45:44,440 --> 00:45:46,680 As darkness falls, 608 00:45:46,680 --> 00:45:48,320 owls come out to hunt. 609 00:45:56,520 --> 00:45:59,920 Bandita and Snap need to fight for their turf. 610 00:46:02,040 --> 00:46:05,040 SCREECHING AND CHITTERING 611 00:46:08,000 --> 00:46:11,320 These owls are three times their size, 612 00:46:11,320 --> 00:46:15,320 so the feisty stoats are punching well above their weight. 613 00:46:32,000 --> 00:46:37,480 Their courage and tenacity means Bandita and Snap are victorious. 614 00:46:39,080 --> 00:46:42,360 They've secured the territory and food for the family. 615 00:46:58,760 --> 00:47:02,960 To be truly independent, the kits have one more test. 616 00:47:02,960 --> 00:47:05,280 They need to hunt their own food. 617 00:47:07,480 --> 00:47:10,880 Fortunately, all stoats have a secret weapon - 618 00:47:10,880 --> 00:47:14,040 an exceptionally strong killing bite. 619 00:47:16,920 --> 00:47:20,920 They can take down a rabbit - an animal five times their size - 620 00:47:20,920 --> 00:47:23,000 with one deadly strike. 621 00:47:27,240 --> 00:47:31,040 But the strongest bite, pound for pound, 622 00:47:31,040 --> 00:47:35,160 is thought to come from the stoat's cousin, the weasel. 623 00:47:44,280 --> 00:47:46,920 At only 15 centimetres long - 624 00:47:46,920 --> 00:47:49,080 just over the length of a £5 note - 625 00:47:49,080 --> 00:47:52,360 they are the smallest carnivore on Earth. 626 00:47:55,960 --> 00:47:59,520 So could they really have the most powerful bite? 627 00:48:10,920 --> 00:48:14,160 North Carolina, on America's East Coast. 628 00:48:19,320 --> 00:48:22,080 Dr Adam Hartstone-Rose and his team 629 00:48:22,080 --> 00:48:25,520 are studying bite force in an entirely new way. 630 00:48:29,400 --> 00:48:32,760 The way that we get data from a specimen is we'll remove 631 00:48:32,760 --> 00:48:36,520 each of the muscles that are responsible for closing the jaws, 632 00:48:36,520 --> 00:48:38,840 and by analysing those muscle fibres, 633 00:48:38,840 --> 00:48:42,600 we can tell whether a muscle is more adapted for stretch and speed 634 00:48:42,600 --> 00:48:46,240 or whether it's more adapted for producing great strength. 635 00:48:48,520 --> 00:48:52,560 So what determines an animal's biting ability? 636 00:48:52,560 --> 00:48:55,400 Bite force is actually a combination of three factors. 637 00:48:55,400 --> 00:48:57,600 The first is the length of the jaws 638 00:48:57,600 --> 00:48:59,880 and then the second factor is the amount of force 639 00:48:59,880 --> 00:49:03,280 that the muscles can actually put into closing the jaws. 640 00:49:03,280 --> 00:49:06,320 And the third factor is the placement of the teeth 641 00:49:06,320 --> 00:49:07,600 along those jaws. 642 00:49:09,000 --> 00:49:13,000 The weasel has a relatively short jaw on a relatively long skull. 643 00:49:13,000 --> 00:49:17,160 The jaw is about 50% of the length of the skull, 644 00:49:17,160 --> 00:49:21,960 and that means that it's able to more efficiently transmit the force 645 00:49:21,960 --> 00:49:23,720 into a higher bite force. 646 00:49:26,880 --> 00:49:29,200 If an animal has a long jaw, 647 00:49:29,200 --> 00:49:33,440 the force it produces is lost over the distance it has to travel. 648 00:49:40,040 --> 00:49:42,120 When an animal has a short jaw, 649 00:49:42,120 --> 00:49:46,600 the force has less distance to travel and to decrease. 650 00:49:49,120 --> 00:49:50,760 The shorter the jaw, 651 00:49:50,760 --> 00:49:52,440 the greater the force. 652 00:49:56,720 --> 00:49:59,160 This is why, in a nut cracker, 653 00:49:59,160 --> 00:50:02,480 the nut is placed as close to the joint as possible - 654 00:50:02,480 --> 00:50:06,720 so that the maximum force goes directly into the nut 655 00:50:06,720 --> 00:50:09,120 and is not dispersed elsewhere. 656 00:50:12,360 --> 00:50:17,280 But the weasel also has another unique adaptation. 657 00:50:17,280 --> 00:50:20,960 For its body size, the weasel has a really long skull 658 00:50:20,960 --> 00:50:23,440 and that leaves a really large surface area 659 00:50:23,440 --> 00:50:26,920 for the attachment of one of the muscles that closes the jaw. 660 00:50:26,920 --> 00:50:29,840 And that means that it can produce a lot of bite force 661 00:50:29,840 --> 00:50:31,440 for such a little guy. 662 00:50:32,680 --> 00:50:35,160 Bigger muscles - or bigger springs - 663 00:50:35,160 --> 00:50:38,560 have a huge impact on the damage a bite can do. 664 00:50:43,680 --> 00:50:48,880 The main muscle which closes the jaw is known as the temporal muscle. 665 00:50:48,880 --> 00:50:51,440 It travels from the top of the skull, 666 00:50:51,440 --> 00:50:54,120 right down to the jaws themselves. 667 00:50:55,480 --> 00:50:59,920 But there's one final factor in the weasel's killer bite. 668 00:50:59,920 --> 00:51:04,040 For such a small animal, it actually has really amazing teeth. 669 00:51:04,040 --> 00:51:08,560 So the canine tooth is really long and sharp and pointy, 670 00:51:08,560 --> 00:51:11,880 which means that the bite force that is transmitted 671 00:51:11,880 --> 00:51:15,640 into these killing teeth is transmitted very powerfully. 672 00:51:20,200 --> 00:51:23,080 As a force disperses across a surface, 673 00:51:23,080 --> 00:51:26,920 the pressure at each individual point is shared around. 674 00:51:29,240 --> 00:51:31,600 Concentrate all that same force 675 00:51:31,600 --> 00:51:35,680 into a smaller area, and the pressure becomes much greater. 676 00:51:37,240 --> 00:51:41,360 This is why the weasels' pointy teeth give them such an edge. 677 00:51:41,360 --> 00:51:46,400 All their muscle force is focused into a razor-sharp point. 678 00:51:51,080 --> 00:51:52,920 Combining all three parts - 679 00:51:52,920 --> 00:51:55,880 the shorter jaws, creating better leverage, 680 00:51:55,880 --> 00:51:59,240 the larger springs, representing more powerful muscles, 681 00:51:59,240 --> 00:52:02,320 and the sharp teeth, to really concentrate all of that force - 682 00:52:02,320 --> 00:52:04,920 this really creates the ultimate bite. 683 00:52:17,120 --> 00:52:20,800 And when the weasel's dissection data is analysed, 684 00:52:20,800 --> 00:52:23,880 the results are extraordinary. 685 00:52:23,880 --> 00:52:28,680 It has relatively higher bite force than the lion and the tiger, 686 00:52:28,680 --> 00:52:31,760 pound for pound. Higher than any of the bears - 687 00:52:31,760 --> 00:52:34,080 higher than a brown bear or a polar bear. 688 00:52:34,080 --> 00:52:35,520 It's quite surprising. 689 00:52:35,520 --> 00:52:37,800 They're frightening little guys for their body size. 690 00:52:37,800 --> 00:52:39,240 That's quite impressive. 691 00:52:46,360 --> 00:52:49,400 Adam can demonstrate just how impressive this is 692 00:52:49,400 --> 00:52:50,960 for such a tiny creature. 693 00:52:52,680 --> 00:52:54,560 If we were to take this weasel 694 00:52:54,560 --> 00:52:57,480 and scale it up to the body size of this huge tiger, 695 00:52:57,480 --> 00:53:00,160 then what we would find is that the skull 696 00:53:00,160 --> 00:53:04,560 would actually be 40% longer than the tiger's skull and 20% wider. 697 00:53:04,560 --> 00:53:06,640 Their muscles would be much bigger, 698 00:53:06,640 --> 00:53:09,800 and their teeth longer and sharper. 699 00:53:09,800 --> 00:53:14,800 And so, that would really make this, essentially, a super predator. 700 00:53:14,800 --> 00:53:16,840 Imagine what it would be like 701 00:53:16,840 --> 00:53:19,840 to be chased by one of these fearsome predators. 702 00:53:22,280 --> 00:53:24,120 WEASEL SQUEAKS 703 00:53:28,400 --> 00:53:31,720 This amazing bite force is what makes weasels 704 00:53:31,720 --> 00:53:35,920 one of the most unparalleled predators on the planet. 705 00:53:53,400 --> 00:53:55,760 In Weasel Town, rescued weasel Twiz 706 00:53:55,760 --> 00:53:59,640 is showing all the signs that she, too, could be a successful hunter. 707 00:54:02,040 --> 00:54:05,160 She's now ready to move into an outdoor enclosure 708 00:54:05,160 --> 00:54:06,840 and become more independent. 709 00:54:09,200 --> 00:54:12,240 It's really crucial for her that we get her thinking she's a weasel 710 00:54:12,240 --> 00:54:14,600 rather than part of a human family. 711 00:54:14,600 --> 00:54:16,800 TWIZ CHITTERS 712 00:54:21,680 --> 00:54:24,920 This will be one of the last times I handle her. 713 00:54:24,920 --> 00:54:27,520 Fabulous little animal - real character. 714 00:54:34,760 --> 00:54:36,840 I'm going to miss her, you know? 715 00:54:36,840 --> 00:54:39,480 It's going to be difficult to let her go. 716 00:54:46,200 --> 00:54:47,720 She looks quite happy, 717 00:54:47,720 --> 00:54:51,400 so I think we just leave her now to explore her new area. 718 00:55:06,720 --> 00:55:09,160 After a few weeks of independence, 719 00:55:09,160 --> 00:55:12,840 Rob feels Twiz is ready for the next milestone. 720 00:55:12,840 --> 00:55:15,640 She's a excellent climber, she tunnels, 721 00:55:15,640 --> 00:55:18,240 so I think she's really at the stage now 722 00:55:18,240 --> 00:55:20,920 where she's ready to be released into the wild. 723 00:55:26,200 --> 00:55:27,680 DOOR CLACKS 724 00:55:27,680 --> 00:55:29,720 There we go. The door's open. 725 00:55:29,720 --> 00:55:31,320 So we'll wait and see. 726 00:55:34,320 --> 00:55:37,760 Twiz takes some cautious steps towards freedom. 727 00:55:39,040 --> 00:55:41,040 She's going really slowly, 728 00:55:41,040 --> 00:55:43,320 investigating everywhere, sniffing. 729 00:55:43,320 --> 00:55:48,360 For now at least, she joins the other weasels of Weasel Town. 730 00:55:57,080 --> 00:56:00,120 I've done my best to teach Twiz everything I can 731 00:56:00,120 --> 00:56:02,000 to become a wild weasel 732 00:56:02,000 --> 00:56:04,840 and it's really exciting to see how she's getting on. 733 00:56:20,640 --> 00:56:23,520 Across the garden, in Stoat City, 734 00:56:23,520 --> 00:56:27,160 Bandita's kits are also ready to leave home. 735 00:56:34,360 --> 00:56:38,120 Bandita has done whatever it took to keep her kits safe. 736 00:56:42,480 --> 00:56:46,040 This first-time mother has nurtured them 737 00:56:46,040 --> 00:56:48,400 and fought to keep them fed. 738 00:56:52,320 --> 00:56:55,000 She's taught them everything she knows... 739 00:56:57,640 --> 00:57:00,320 ..and they've had some fun along the way. 740 00:57:02,440 --> 00:57:06,160 Rob's garden has revealed a unique insight into their lives, 741 00:57:06,160 --> 00:57:07,880 but more than anything, 742 00:57:07,880 --> 00:57:11,240 it's been a safe haven for this family to thrive. 743 00:57:11,240 --> 00:57:13,880 I'm really proud of Bandita. 744 00:57:13,880 --> 00:57:17,320 She's raised these three really strong, independent stoats, 745 00:57:17,320 --> 00:57:20,560 ready to go forth and find new territories. 746 00:57:22,000 --> 00:57:23,840 As the kits reach adulthood, 747 00:57:23,840 --> 00:57:26,600 they will seek out new areas to live alone. 748 00:57:26,600 --> 00:57:30,120 But Rob hopes that won't be the end of following their story. 749 00:57:31,440 --> 00:57:33,520 I obviously hope to see them again 750 00:57:33,520 --> 00:57:36,840 and maybe even, like Bandita, get one of them back here breeding. 751 00:57:36,840 --> 00:57:39,960 That would be just the icing on the cake for me. 752 00:57:52,440 --> 00:57:55,120 There's so much more to the weasel family 753 00:57:55,120 --> 00:57:58,000 than their reputation would suggest. 754 00:58:01,000 --> 00:58:05,560 Their cunning is merely proof of their impressive intelligence. 755 00:58:08,960 --> 00:58:13,360 Their sneaky manoeuvres are a sign of their remarkable agility. 756 00:58:16,680 --> 00:58:20,600 And their savage nature is a nod to their exceptional bite. 757 00:58:23,360 --> 00:58:25,200 Feisty and fearless, 758 00:58:25,200 --> 00:58:28,960 they are some of the most accomplished predators 759 00:58:28,960 --> 00:58:30,640 on the planet.