1 00:00:05,040 --> 00:00:08,480 [sweeping orchestral music playing] 2 00:00:23,200 --> 00:00:25,880 [Attenborough] The natural world is full of colours 3 00:00:25,960 --> 00:00:27,840 that we often take for granted. 4 00:00:37,480 --> 00:00:40,200 There are few animals more brilliantly coloured 5 00:00:40,280 --> 00:00:42,480 than these scarlet macaws. 6 00:00:43,480 --> 00:00:47,160 Animals can use colour for all kinds of different reasons, 7 00:00:47,240 --> 00:00:51,520 and some have colours that we ourselves can't even see. 8 00:00:54,600 --> 00:00:56,960 But not all colours are what they seem. 9 00:00:59,440 --> 00:01:02,640 Some animals also use colours to hide… 10 00:01:07,360 --> 00:01:09,640 colours that make them disappear, 11 00:01:11,360 --> 00:01:14,280 colours that create optical illusions, 12 00:01:16,120 --> 00:01:19,720 and colours that are used to trick and deceive. 13 00:01:21,160 --> 00:01:23,480 To understand how these colours work, 14 00:01:23,560 --> 00:01:27,000 we need to see them from an animal's perspective. 15 00:01:29,080 --> 00:01:31,440 With the help of our specialist cameras, 16 00:01:32,080 --> 00:01:33,720 we can now do that… 17 00:01:36,680 --> 00:01:42,040 and discover how some animals have become masters of disguise. 18 00:01:55,920 --> 00:01:58,760 [suspenseful orchestral music playing] 19 00:02:09,920 --> 00:02:15,360 The Indian subcontinent is home to some truly spectacular animals. 20 00:02:18,640 --> 00:02:20,880 [bird calling] 21 00:02:25,960 --> 00:02:30,480 Most, like these peafowl, use colour to attract attention, 22 00:02:31,160 --> 00:02:33,160 and the colours they've developed 23 00:02:33,240 --> 00:02:36,720 are influenced by the way they see the world. 24 00:02:40,040 --> 00:02:43,280 But flashy colours can also come at a cost, 25 00:02:44,840 --> 00:02:48,800 and sometimes, it's better to remain out of sight. 26 00:02:54,080 --> 00:02:56,440 So some animals use their colours 27 00:02:56,520 --> 00:03:00,160 to help them hide and disappear into the background. 28 00:03:06,880 --> 00:03:08,920 One such animal lives here, 29 00:03:09,000 --> 00:03:11,360 in the forests of Central India. 30 00:03:13,600 --> 00:03:16,760 It's one of the most formidable hunters on earth. 31 00:03:19,200 --> 00:03:20,560 A Bengal tiger. 32 00:03:21,080 --> 00:03:22,080 A female. 33 00:03:24,880 --> 00:03:27,200 She's one of the world's biggest cats, 34 00:03:28,080 --> 00:03:32,760 and remaining out of sight is not easy when you are as large as she is. 35 00:03:36,640 --> 00:03:40,880 Her orange and black coat is crucial to her success. 36 00:03:44,320 --> 00:03:46,440 To have any chance of catching a meal, 37 00:03:46,520 --> 00:03:50,760 she has to get to within a few metres of her prey. 38 00:04:11,960 --> 00:04:14,760 She keeps to the cover of the trees 39 00:04:14,840 --> 00:04:16,960 and slowly makes her approach. 40 00:04:23,040 --> 00:04:25,840 She may appear conspicuous to our eyes, 41 00:04:26,640 --> 00:04:29,440 but not so to these chital deer. 42 00:04:33,200 --> 00:04:37,480 Chital have only two types of colour receptors in their eyes, 43 00:04:37,560 --> 00:04:39,280 compared to our three, 44 00:04:40,200 --> 00:04:44,880 which means that they are effectively blind to red and orange. 45 00:04:48,960 --> 00:04:52,480 So to the deer, the tiger isn't orange at all. 46 00:04:56,720 --> 00:04:59,160 This is how we see the world… 47 00:05:01,280 --> 00:05:03,520 and this is how the deer do. 48 00:05:05,600 --> 00:05:10,160 The tiger's orange coat, to them, is a muted shade of green, 49 00:05:11,200 --> 00:05:14,440 so it's nearly impossible for the deer to register. 50 00:05:15,800 --> 00:05:18,280 [suspenseful orchestral music continues] 51 00:05:25,960 --> 00:05:27,480 She creeps closer. 52 00:05:35,840 --> 00:05:37,960 The chital don't see her. 53 00:05:56,880 --> 00:06:00,360 The odds appear stacked in the tiger's favour. 54 00:06:09,400 --> 00:06:12,000 But the deer aren't entirely defenceless. 55 00:06:14,840 --> 00:06:17,720 They have help from an unusual ally. 56 00:06:20,080 --> 00:06:21,440 Langur monkeys. 57 00:06:22,440 --> 00:06:25,000 They're known as the eyes of the forest, 58 00:06:25,080 --> 00:06:27,840 and their colour vision is excellent. 59 00:06:36,840 --> 00:06:40,920 Their eyes, like ours, have three types of colour receptors, 60 00:06:41,000 --> 00:06:42,920 and they can see orange. 61 00:06:50,440 --> 00:06:52,000 [calling] 62 00:06:52,720 --> 00:06:55,360 [monkeys calling] 63 00:06:55,440 --> 00:06:56,480 [calling] 64 00:06:56,560 --> 00:06:58,600 [monkeys calling] 65 00:07:00,480 --> 00:07:04,200 The langur sounded the alarm before she could get close enough. 66 00:07:06,520 --> 00:07:08,520 [panting] 67 00:07:12,840 --> 00:07:15,080 If the langurs can easily spot her, 68 00:07:15,160 --> 00:07:17,560 why, then, is the tiger orange at all? 69 00:07:18,120 --> 00:07:19,680 Why isn't she green? 70 00:07:22,440 --> 00:07:26,440 That's because mammals are unable to develop green pigments, 71 00:07:27,400 --> 00:07:30,200 so it seems the next best solution for the tiger 72 00:07:30,280 --> 00:07:31,680 is to have orange fur, 73 00:07:31,760 --> 00:07:34,320 which appears green to her main prey. 74 00:07:37,400 --> 00:07:38,760 [growls softly] 75 00:07:44,200 --> 00:07:46,840 She will have to find a new target. 76 00:07:55,920 --> 00:07:58,520 Down by the water, she finds one. 77 00:07:59,400 --> 00:08:00,800 Sambar deer. 78 00:08:03,040 --> 00:08:06,080 Sambar don't keep company with monkeys. 79 00:08:06,160 --> 00:08:08,240 They are on their own. 80 00:08:10,080 --> 00:08:13,160 They have the same limited eyesight as the chital, 81 00:08:14,200 --> 00:08:16,680 but ears like satellite dishes. 82 00:08:19,080 --> 00:08:21,600 If she treads on a twig and it snaps, 83 00:08:21,680 --> 00:08:24,480 the hunt will be over before it began. 84 00:08:26,720 --> 00:08:28,040 [snarls] 85 00:08:28,120 --> 00:08:30,120 [suspenseful orchestral music playing] 86 00:09:20,080 --> 00:09:22,680 The deer seem to sense danger. 87 00:09:27,440 --> 00:09:29,280 They still can't see her. 88 00:09:35,960 --> 00:09:38,440 [suspenseful orchestral music intensifies] 89 00:09:41,960 --> 00:09:42,960 [sambar bleats] 90 00:10:14,080 --> 00:10:15,800 [sambar calling] 91 00:10:17,960 --> 00:10:19,160 [water splashing] 92 00:10:22,280 --> 00:10:24,800 Despite her effective camouflage, 93 00:10:25,360 --> 00:10:27,680 most hunts end like this. 94 00:10:28,840 --> 00:10:32,680 Less than 10% of her attacks are successful. 95 00:10:36,320 --> 00:10:38,480 But without her orange fur, 96 00:10:38,560 --> 00:10:40,560 her chances would be even lower. 97 00:10:41,280 --> 00:10:45,000 It is her colours that are key to her survival. 98 00:10:49,840 --> 00:10:51,840 [wind whistling] 99 00:10:53,440 --> 00:10:56,000 The Cairngorm Mountains in Scotland. 100 00:10:57,320 --> 00:11:00,840 Here, there are special problems for the hunted. 101 00:11:04,600 --> 00:11:08,880 Some animals have developed camouflage of such perfection 102 00:11:08,960 --> 00:11:12,640 that they are virtually invisible against their surroundings. 103 00:11:13,400 --> 00:11:16,200 But what happens when those surroundings change? 104 00:11:16,880 --> 00:11:19,920 Well, then, of course, the animals have to change too. 105 00:11:23,840 --> 00:11:27,360 These mountains are home to a particular kind of grouse 106 00:11:27,440 --> 00:11:29,080 called the ptarmigan. 107 00:11:29,600 --> 00:11:31,520 [ptarmigan croaking] 108 00:11:35,560 --> 00:11:38,680 Their mottled brown feathers make them inconspicuous 109 00:11:38,760 --> 00:11:40,520 among the rocks and heather. 110 00:11:45,200 --> 00:11:46,520 But in winter, 111 00:11:47,000 --> 00:11:49,920 these mountains are hard places in which to live. 112 00:11:51,560 --> 00:11:52,640 Temperatures drop, 113 00:11:52,720 --> 00:11:57,280 and the land can, overnight, be covered by a blanket of snow. 114 00:11:59,640 --> 00:12:03,840 Most birds, by now, have gone south to warmer parts of the world, 115 00:12:04,360 --> 00:12:06,080 but not the ptarmigan. 116 00:12:07,920 --> 00:12:09,120 When winter comes, 117 00:12:09,200 --> 00:12:12,080 they undergo the most extraordinary change. 118 00:12:13,680 --> 00:12:18,440 They replace their brown feathers with pure white ones. 119 00:12:21,840 --> 00:12:24,440 They do so for a simple reason. 120 00:12:25,120 --> 00:12:27,240 They must go unnoticed. 121 00:12:27,320 --> 00:12:29,160 They need to hide. 122 00:12:29,880 --> 00:12:31,880 [tense orchestral music playing] 123 00:12:34,240 --> 00:12:35,760 This open habitat 124 00:12:35,840 --> 00:12:39,040 makes the ptarmigan very vulnerable to predators. 125 00:12:42,640 --> 00:12:44,960 Being the right colour is crucial. 126 00:12:46,600 --> 00:12:50,320 Now they are invisible even to a keen-eyed eagle. 127 00:12:55,000 --> 00:12:59,440 Ptarmigan are not the only animals to use this disappearing act. 128 00:13:04,240 --> 00:13:06,440 So does the Arctic fox, 129 00:13:07,680 --> 00:13:09,400 snowshoe hares, 130 00:13:10,040 --> 00:13:11,320 and weasels. 131 00:13:12,440 --> 00:13:14,560 All, with the coming of winter, 132 00:13:14,640 --> 00:13:17,360 change their coats and vanish from sight. 133 00:13:21,280 --> 00:13:26,120 Their transformation is triggered by the decreasing daylight, 134 00:13:26,200 --> 00:13:28,240 and, over several weeks, 135 00:13:28,320 --> 00:13:31,880 they replace their brown costumes with white ones. 136 00:13:44,240 --> 00:13:46,720 So changing colour with the seasons, 137 00:13:46,800 --> 00:13:48,320 for some animals, 138 00:13:48,400 --> 00:13:51,720 is the only way to avoid becoming a meal. 139 00:13:51,800 --> 00:13:53,800 [wind whistling] 140 00:13:57,680 --> 00:13:59,400 But many plants, of course, 141 00:13:59,480 --> 00:14:00,840 do the reverse. 142 00:14:00,920 --> 00:14:03,560 [whimsical orchestral music playing] 143 00:14:04,160 --> 00:14:05,240 In spring, 144 00:14:05,320 --> 00:14:09,880 they produce colour to declare that they are providing food, 145 00:14:09,960 --> 00:14:10,840 nectar. 146 00:14:12,960 --> 00:14:15,680 Bees and many other insects love it. 147 00:14:17,440 --> 00:14:18,800 In spring and summer, 148 00:14:18,880 --> 00:14:22,680 they travel busily from flower to flower collecting it. 149 00:14:23,960 --> 00:14:26,240 And when the bees leave to look for more, 150 00:14:26,320 --> 00:14:28,800 they inadvertently take pollen with them, 151 00:14:28,880 --> 00:14:32,040 which then fertilises the next flowers they visit. 152 00:14:34,840 --> 00:14:38,560 But there's a hunter here that exploits this relationship. 153 00:14:40,600 --> 00:14:42,040 A crab spider. 154 00:14:45,760 --> 00:14:49,040 She's tiny, no bigger than a fingernail, 155 00:14:49,120 --> 00:14:51,160 and she's waiting for her prey. 156 00:14:57,440 --> 00:15:00,080 Almost the same colour as her background, 157 00:15:00,680 --> 00:15:02,640 she's virtually invisible. 158 00:15:24,880 --> 00:15:27,080 No more honey for her. 159 00:15:32,560 --> 00:15:36,080 But, of course, the spider's hunting grounds are limited. 160 00:15:36,160 --> 00:15:38,120 Not all flowers are yellow. 161 00:15:41,360 --> 00:15:43,600 When she sits on a pure white petal, 162 00:15:43,680 --> 00:15:45,880 she immediately becomes obvious. 163 00:15:50,440 --> 00:15:53,960 She will never catch a bee while she's so conspicuous. 164 00:15:55,960 --> 00:15:58,000 So, she changes. 165 00:16:00,800 --> 00:16:04,800 She breaks down the yellow pigments in the outer layer of her skin 166 00:16:04,880 --> 00:16:07,360 to expose special crystals underneath 167 00:16:07,440 --> 00:16:10,880 that act like tiny mirrors and reflect the light. 168 00:16:16,720 --> 00:16:18,680 It may take a few days, 169 00:16:18,760 --> 00:16:20,800 but she turns from yellow 170 00:16:20,880 --> 00:16:22,120 to white. 171 00:16:29,760 --> 00:16:32,800 Changing colour isn't the spider's only trick. 172 00:16:34,120 --> 00:16:36,800 There's more to this story than meets the eye. 173 00:16:45,040 --> 00:16:48,320 Bees can see colours that we cannot. 174 00:16:49,040 --> 00:16:52,000 They can see ultraviolet colours. 175 00:16:59,720 --> 00:17:01,920 As they come in to land on a flower, 176 00:17:02,000 --> 00:17:04,040 they use special sensors 177 00:17:04,120 --> 00:17:08,240 that can detect ultraviolet patterns on the flower's petals. 178 00:17:14,360 --> 00:17:18,800 We can see them too with our special UV camera. 179 00:17:30,240 --> 00:17:32,560 There are dark lines on the petals 180 00:17:32,640 --> 00:17:35,240 that mark the landing strips for the bees, 181 00:17:35,960 --> 00:17:37,800 guiding them to the nectar. 182 00:17:47,240 --> 00:17:48,640 The spider, however, 183 00:17:48,720 --> 00:17:52,480 has developed a way to exploit these signals. 184 00:17:59,800 --> 00:18:02,400 Watching her with our UV camera, 185 00:18:02,480 --> 00:18:05,920 we can see that she reflects ultraviolet light, 186 00:18:06,000 --> 00:18:09,800 so she appears even more conspicuous sitting on a flower. 187 00:18:13,800 --> 00:18:17,520 This extra brilliance acts as a kind of super signal, 188 00:18:17,600 --> 00:18:19,680 which the bee can't resist. 189 00:18:27,360 --> 00:18:30,480 And the spider benefits. 190 00:18:36,440 --> 00:18:39,600 In fact, the bees are more than three times as likely 191 00:18:39,680 --> 00:18:43,720 to visit flowers with UV-reflecting spiders on them 192 00:18:43,800 --> 00:18:45,000 than those without. 193 00:18:58,000 --> 00:19:02,160 The crab spider uses a sophisticated range of colours 194 00:19:02,240 --> 00:19:04,320 to deceive its prey. 195 00:19:07,080 --> 00:19:11,760 But colour can also be used in a simpler, even more surprising way 196 00:19:11,840 --> 00:19:13,360 to confuse the enemy. 197 00:19:16,880 --> 00:19:21,040 And on the plains of Kenya's Masai Mara, there's one animal 198 00:19:21,120 --> 00:19:23,520 that uses just two colours 199 00:19:23,600 --> 00:19:25,280 to outwit its predators. 200 00:19:25,360 --> 00:19:27,360 [laid-back orchestral music playing] 201 00:19:29,800 --> 00:19:30,760 The zebra. 202 00:19:35,240 --> 00:19:38,800 Its black and white coat makes it extremely obvious 203 00:19:38,880 --> 00:19:41,680 as it grazes out on the open grasslands. 204 00:19:47,480 --> 00:19:50,920 Other grazers have softer, gently varied colouration, 205 00:19:51,000 --> 00:19:53,440 which blends with their background. 206 00:19:56,280 --> 00:20:01,040 So it seems strange that zebras, apparently, do quite the opposite. 207 00:20:04,680 --> 00:20:09,360 Particularly as they live in a world where there are so many hunters. 208 00:20:10,160 --> 00:20:12,160 [menacing orchestral music playing] 209 00:20:13,000 --> 00:20:13,960 Lions, 210 00:20:15,600 --> 00:20:16,720 hyenas, 211 00:20:18,080 --> 00:20:19,160 and cheetah. 212 00:20:20,200 --> 00:20:21,520 [snarling] 213 00:20:21,600 --> 00:20:23,280 [growling] 214 00:20:25,960 --> 00:20:30,040 The boldly striped zebra seem to be asking for trouble. 215 00:20:31,480 --> 00:20:33,200 How do they get away with it? 216 00:20:34,640 --> 00:20:38,920 The question has been hotly debated by naturalists for centuries. 217 00:20:40,400 --> 00:20:42,200 [zebras snorting] 218 00:20:43,000 --> 00:20:46,520 New research is now suggesting an answer. 219 00:20:49,200 --> 00:20:51,120 To understand how it might work, 220 00:20:51,200 --> 00:20:54,440 we need to consider the particular colours involved. 221 00:20:55,320 --> 00:20:58,560 Black and white are two of the most contrasting colours. 222 00:20:59,760 --> 00:21:03,000 And no two animals have exactly the same pattern, 223 00:21:03,080 --> 00:21:06,840 so each has a unique whole-body fingerprint. 224 00:21:06,920 --> 00:21:08,920 [tense orchestral music playing] 225 00:21:13,680 --> 00:21:15,680 But when the zebras move, 226 00:21:15,760 --> 00:21:18,280 the stripes create confusion. 227 00:21:20,040 --> 00:21:22,400 It's known as motion dazzle. 228 00:21:24,840 --> 00:21:30,120 And it makes it difficult for a predator to keep focused on one particular target. 229 00:21:45,280 --> 00:21:47,720 The cheetah, looking for a meal. 230 00:21:59,440 --> 00:22:00,560 [zebra snorts] 231 00:22:00,640 --> 00:22:02,640 [suspenseful orchestral music playing] 232 00:22:03,760 --> 00:22:05,760 To make a successful strike, 233 00:22:05,840 --> 00:22:08,400 they must judge the distance accurately 234 00:22:08,480 --> 00:22:10,280 and time it perfectly. 235 00:22:18,760 --> 00:22:22,040 So if a zebra's stripes can confuse the cheetah 236 00:22:22,120 --> 00:22:24,200 just for a few crucial seconds, 237 00:22:25,280 --> 00:22:26,400 it may escape. 238 00:22:45,400 --> 00:22:48,320 But there's another threat on these plains. 239 00:22:52,280 --> 00:22:53,480 Flies. 240 00:22:56,680 --> 00:22:59,360 They are a real pest here. 241 00:23:00,920 --> 00:23:02,760 They're not just a nuisance. 242 00:23:02,840 --> 00:23:04,240 They carry diseases, 243 00:23:04,320 --> 00:23:07,640 some of which are particularly nasty, even deadly. 244 00:23:15,200 --> 00:23:17,480 Despite the huge numbers of flies, 245 00:23:17,560 --> 00:23:21,520 the zebras appear remarkably untroubled by them. 246 00:23:21,600 --> 00:23:23,600 [laid-back orchestral music playing] 247 00:23:27,200 --> 00:23:29,240 There are plenty of flies around… 248 00:23:31,800 --> 00:23:34,960 but few actually land on the zebra. 249 00:23:37,960 --> 00:23:40,760 One theory is that the black and white stripes 250 00:23:40,840 --> 00:23:44,440 make it difficult for flies to judge the distance. 251 00:23:47,400 --> 00:23:48,800 To test this idea, 252 00:23:48,880 --> 00:23:52,560 scientists counted how many flies landed on animals 253 00:23:52,640 --> 00:23:54,920 with gently graded colours 254 00:23:55,000 --> 00:23:58,160 and how many landed on the zebras' stripes. 255 00:24:03,560 --> 00:24:07,800 They found that four times fewer flies landed on zebras 256 00:24:07,880 --> 00:24:10,640 than on their more plainly coloured neighbours. 257 00:24:15,720 --> 00:24:17,240 Why should that be? 258 00:24:20,280 --> 00:24:23,760 It seems it's another consequence of those stripes. 259 00:24:26,520 --> 00:24:27,920 They confuse the flies 260 00:24:28,000 --> 00:24:30,560 as they make their final approach to settle. 261 00:24:33,800 --> 00:24:37,800 Perhaps this creates a visual blurring for the flies, 262 00:24:37,880 --> 00:24:40,000 much as it does for a cheetah. 263 00:24:42,440 --> 00:24:45,960 So it seems that the zebras' patterns of stripes 264 00:24:46,040 --> 00:24:49,960 creates an optical effect that helps protect them from enemies, 265 00:24:50,040 --> 00:24:52,120 both large and small. 266 00:25:07,600 --> 00:25:11,400 While zebras use different patterns to confuse their enemies, 267 00:25:12,320 --> 00:25:14,040 on the island of Cuba, 268 00:25:14,600 --> 00:25:18,200 there are smaller and rather slower-moving creatures 269 00:25:18,280 --> 00:25:20,160 that do a similar thing. 270 00:25:25,480 --> 00:25:27,880 This is Polymita picta, 271 00:25:28,440 --> 00:25:30,800 a Cuban painted snail. 272 00:25:32,040 --> 00:25:34,040 [tranquil orchestral music playing] 273 00:25:34,880 --> 00:25:38,440 You might think that this one is an exceptionally lovely, 274 00:25:38,520 --> 00:25:40,120 eye-catching individual. 275 00:25:43,440 --> 00:25:45,360 But it's not, by any means, 276 00:25:45,440 --> 00:25:48,680 the only snail that is so beautifully decorated. 277 00:25:54,680 --> 00:25:57,600 No two individuals are exactly the same, 278 00:25:58,400 --> 00:26:01,080 yet all these belong to the same species. 279 00:26:06,640 --> 00:26:10,160 There are also five other species of Polymita here. 280 00:26:11,240 --> 00:26:14,240 Each snail has its own unique combination 281 00:26:14,320 --> 00:26:16,040 of colours and stripes. 282 00:26:34,080 --> 00:26:36,160 Their colours come from their diet. 283 00:26:36,680 --> 00:26:39,160 Lichen and mosses rich in minerals 284 00:26:39,240 --> 00:26:41,840 that give the shells these stunning colours. 285 00:26:43,160 --> 00:26:46,960 They differ according to the particular mix of plants 286 00:26:47,040 --> 00:26:49,160 that each snail has been eating. 287 00:26:49,800 --> 00:26:54,600 Variations of individuals within a species is not uncommon in the natural world. 288 00:26:55,120 --> 00:26:57,040 It's called polymorphism. 289 00:26:58,640 --> 00:27:02,640 But it's particularly marked among Cuban snails. 290 00:27:11,520 --> 00:27:15,440 Some scientists believe that the variation in itself 291 00:27:15,520 --> 00:27:18,680 may be a kind of defence against predators. 292 00:27:23,040 --> 00:27:25,120 But how could that work? 293 00:27:26,280 --> 00:27:28,160 [menacing orchestral music playing] 294 00:27:28,240 --> 00:27:30,600 Most animals looking for prey 295 00:27:30,680 --> 00:27:33,520 have a search image in their minds. 296 00:27:34,800 --> 00:27:37,680 They scan their surroundings looking for a victim 297 00:27:37,760 --> 00:27:40,120 that matches their expectations. 298 00:27:41,640 --> 00:27:45,000 If they see something they recognise, they'll go for it. 299 00:27:46,200 --> 00:27:50,400 And that's where the snails' varying colours may come in. 300 00:27:52,000 --> 00:27:54,760 The great range of different tints and patterns, 301 00:27:54,840 --> 00:27:57,640 it seems, confuses the birds. 302 00:27:59,600 --> 00:28:03,040 He's never seen one quite like this before. 303 00:28:08,200 --> 00:28:11,640 And while the bird is wondering whether it's edible or not, 304 00:28:13,000 --> 00:28:17,920 the snail can slowly make a getaway. 305 00:28:24,000 --> 00:28:29,160 So it seems that colour can both conceal and confuse. 306 00:28:30,680 --> 00:28:35,120 And sometimes it's used in yet a third quite different way. 307 00:28:36,680 --> 00:28:40,800 Some poisonous animals, like this little ladybird, 308 00:28:40,880 --> 00:28:42,880 use colour as a warning. 309 00:28:43,720 --> 00:28:47,240 It's bright red, and that's a message which says, 310 00:28:47,320 --> 00:28:48,360 "Keep away." 311 00:28:49,160 --> 00:28:50,080 "I'm poisonous." 312 00:28:51,960 --> 00:28:56,120 Red, black, and yellow are widely understood as warnings. 313 00:28:56,920 --> 00:28:59,800 So the ladybird's message is a truthful one. 314 00:28:59,880 --> 00:29:01,760 It is poisonous. 315 00:29:04,480 --> 00:29:07,480 But some animals that are, in fact, harmless 316 00:29:07,560 --> 00:29:11,920 have found it profitable to develop these warning colours themselves. 317 00:29:12,000 --> 00:29:14,000 [serene orchestral music playing] 318 00:29:15,680 --> 00:29:18,640 This African queen butterfly, like the ladybird, 319 00:29:18,720 --> 00:29:20,840 is indeed very poisonous. 320 00:29:23,400 --> 00:29:28,320 But this is a different species entirely, a Danaid butterfly. 321 00:29:30,080 --> 00:29:32,800 It has almost exactly the same colouration, 322 00:29:32,880 --> 00:29:34,640 yet it's perfectly edible. 323 00:29:35,880 --> 00:29:37,000 It is, you might say, 324 00:29:37,080 --> 00:29:39,240 using its colours and patterns 325 00:29:39,320 --> 00:29:40,880 to tell a lie. 326 00:29:43,440 --> 00:29:46,240 To our eyes, and to that of the predators, 327 00:29:46,320 --> 00:29:50,960 poisonous and non-poisonous individuals look almost identical. 328 00:29:51,720 --> 00:29:53,120 And that's the point. 329 00:29:53,200 --> 00:29:57,440 The Danaid mimics the colours and patterns of the African queen, 330 00:29:57,520 --> 00:29:58,880 and so it isn't eaten. 331 00:30:02,680 --> 00:30:06,440 Mimicry like this occurs quite frequently among insects. 332 00:30:08,400 --> 00:30:11,600 The yellow and black stripes of this harmless hoverfly 333 00:30:11,680 --> 00:30:16,120 resemble the warning colours of bees and wasps that sting, 334 00:30:16,200 --> 00:30:17,920 so it's left alone. 335 00:30:20,400 --> 00:30:23,120 Other animals use mimicry to hide. 336 00:30:25,800 --> 00:30:28,600 This moth resembles a broken twig. 337 00:30:33,680 --> 00:30:38,280 A kind of mantis closely matches the shape and colours of a leaf. 338 00:30:42,200 --> 00:30:45,920 Another mantis is shaped and coloured like a flower… 339 00:30:47,920 --> 00:30:50,520 and gets a reward for the resemblance. 340 00:30:54,160 --> 00:30:59,080 And one particular caterpillar has come to look like a tiny snake. 341 00:31:03,160 --> 00:31:08,360 While this butterfly's wings take on the appearance of dead leaves. 342 00:31:18,840 --> 00:31:21,760 But there are some animals which use mimicry 343 00:31:21,840 --> 00:31:24,040 for a rather more sinister purpose. 344 00:31:25,760 --> 00:31:30,640 And one such creature lives here on Australia's Great Barrier Reef. 345 00:31:31,760 --> 00:31:33,760 [enchanting orchestral music playing] 346 00:31:35,280 --> 00:31:37,000 Just beneath the surface, 347 00:31:37,080 --> 00:31:39,760 the reef is a riot of colour. 348 00:31:43,960 --> 00:31:45,040 But that means 349 00:31:45,120 --> 00:31:48,040 there are great opportunities for deceptions. 350 00:32:00,080 --> 00:32:01,960 A bluestriped blenny. 351 00:32:10,320 --> 00:32:13,120 It lives close to a cleaning station, 352 00:32:13,920 --> 00:32:17,960 a place on the reef where large fish come to get their parasites 353 00:32:18,040 --> 00:32:21,600 picked off by smaller fish that feed on what they remove. 354 00:32:31,080 --> 00:32:34,360 This little wrasse is one of these cleaners. 355 00:32:36,320 --> 00:32:38,920 It has a long-standing relationship 356 00:32:39,000 --> 00:32:40,960 that relies on trust. 357 00:32:43,040 --> 00:32:47,560 The big fish get a health treatment, and the little fish get a meal. 358 00:32:50,240 --> 00:32:54,640 But the blenny has learned how to exploit this trusting relationship. 359 00:32:56,400 --> 00:33:00,040 It leaves its hole and starts looking for a meal. 360 00:33:05,080 --> 00:33:08,120 But the big fish don't seem to trust it. 361 00:33:12,360 --> 00:33:14,720 It's time for a change of costume. 362 00:33:21,880 --> 00:33:25,040 Filmed close up, under controlled conditions, 363 00:33:25,120 --> 00:33:29,520 we can see how the blenny's brown stripes turn black. 364 00:33:36,600 --> 00:33:40,600 The pigment cells in its skin expand and contract 365 00:33:40,680 --> 00:33:43,040 to bring about this subtle change… 366 00:33:45,200 --> 00:33:47,200 but it's enough to do the trick. 367 00:33:52,920 --> 00:33:55,040 The blenny now looks very similar 368 00:33:55,120 --> 00:33:57,560 to a juvenile cleaner wrasse. 369 00:34:04,280 --> 00:34:06,280 It's a devious disguise, 370 00:34:06,360 --> 00:34:09,280 and one that will help it take advantage of the arrangement 371 00:34:09,360 --> 00:34:12,640 the cleaner wrasse has developed with its clients. 372 00:34:12,720 --> 00:34:14,760 [unsettling orchestral music playing] 373 00:34:16,120 --> 00:34:17,600 It's spotted a target. 374 00:34:19,120 --> 00:34:20,520 A butterflyfish. 375 00:34:25,000 --> 00:34:26,520 The blenny hangs back, 376 00:34:26,600 --> 00:34:30,360 allowing an established cleaner wrasse to start work. 377 00:34:42,600 --> 00:34:46,040 Now the blenny slowly moves in, 378 00:34:46,120 --> 00:34:49,120 as if to offer the same service as the wrasse. 379 00:34:49,880 --> 00:34:52,560 [unsettling orchestral music intensifies] 380 00:35:02,440 --> 00:35:04,080 But once within range… 381 00:35:06,080 --> 00:35:07,040 it strikes. 382 00:35:12,840 --> 00:35:16,840 Its razor-sharp teeth have removed not just dead skin, 383 00:35:16,920 --> 00:35:18,960 but a chunk of flesh. 384 00:35:23,880 --> 00:35:27,000 This isn't the treatment the butterflyfish was expecting. 385 00:35:30,800 --> 00:35:33,320 The blenny's deceit may work for a time, 386 00:35:33,400 --> 00:35:36,440 but eventually it has consequences. 387 00:35:38,040 --> 00:35:39,880 Reef fish begin to associate 388 00:35:39,960 --> 00:35:42,480 the distinctive colours of a cleaner wrasse 389 00:35:42,560 --> 00:35:45,000 with the pain of the bites of a blenny. 390 00:35:47,480 --> 00:35:51,440 Then they will eventually stop coming to this cleaning station. 391 00:35:55,440 --> 00:35:59,000 And that is bad for business for the blenny too. 392 00:36:01,640 --> 00:36:04,200 So it's time to let things cool off. 393 00:36:08,120 --> 00:36:12,560 A quick change back to brown and its deception is over. 394 00:36:12,640 --> 00:36:13,680 For now. 395 00:36:15,400 --> 00:36:16,440 All the while, 396 00:36:16,520 --> 00:36:19,400 it keeps its eye on the cleaning station 397 00:36:20,000 --> 00:36:22,360 and waits for its next target. 398 00:36:23,680 --> 00:36:25,680 [birdsong] 399 00:36:34,160 --> 00:36:37,440 Some animals change colour for short periods of time 400 00:36:37,520 --> 00:36:39,160 in order to deceive others, 401 00:36:39,760 --> 00:36:43,160 but some use colour mimicry permanently, 402 00:36:43,240 --> 00:36:47,360 as a method of persuading a different species to rear their young. 403 00:36:50,880 --> 00:36:55,440 One such creature lives here on the grasslands of Southern Zambia. 404 00:36:55,520 --> 00:36:57,840 [whimsical orchestral music playing] 405 00:37:01,120 --> 00:37:03,680 A nest, hidden in the grass. 406 00:37:06,800 --> 00:37:09,840 It belongs to a pair of common waxbills. 407 00:37:17,200 --> 00:37:19,800 They are busy feeding their chicks. 408 00:37:19,880 --> 00:37:21,680 [chicks chirping] 409 00:37:22,200 --> 00:37:24,440 The hungry youngsters open their beaks 410 00:37:24,520 --> 00:37:27,600 to display a conspicuously patterned gape, 411 00:37:28,240 --> 00:37:31,760 which says, in effect, "Food here, please." 412 00:37:34,280 --> 00:37:36,080 And the parent obeys. 413 00:37:52,080 --> 00:37:54,600 But among them, in this nest, 414 00:37:54,680 --> 00:37:56,480 there is an impostor. 415 00:38:00,640 --> 00:38:03,840 One is significantly bigger than the rest. 416 00:38:05,400 --> 00:38:06,720 It hatched from an egg 417 00:38:06,800 --> 00:38:10,200 that was surreptitiously laid in the waxbills' nest 418 00:38:10,280 --> 00:38:12,720 by a pin-tailed whydah. 419 00:38:15,080 --> 00:38:17,560 Having done so, she flew away, 420 00:38:17,640 --> 00:38:20,880 leaving her young to be cared for by the waxbills. 421 00:38:20,960 --> 00:38:23,000 [chicks chirping] 422 00:38:23,080 --> 00:38:25,760 But why do the waxbills feed this impostor? 423 00:38:28,600 --> 00:38:33,520 The parent birds recognise their young by the pattern of their gapes. 424 00:38:37,160 --> 00:38:39,200 And the black and white markings 425 00:38:39,280 --> 00:38:41,400 are characteristic of their species. 426 00:38:43,320 --> 00:38:45,320 But the impostor's markings 427 00:38:45,400 --> 00:38:48,240 closely mimic those of its nest-mates. 428 00:38:49,680 --> 00:38:53,080 And because it's bigger, it takes nearly all the food, 429 00:38:53,160 --> 00:38:55,920 and the young waxbills get little or none. 430 00:39:14,760 --> 00:39:16,000 Two weeks later, 431 00:39:17,520 --> 00:39:20,600 and the young whydah is much bigger. 432 00:39:20,680 --> 00:39:22,680 [tranquil orchestral music playing] 433 00:39:26,000 --> 00:39:28,000 [chicks chirping] 434 00:39:32,560 --> 00:39:33,840 By now, however, 435 00:39:33,920 --> 00:39:37,840 the adult waxbills have accepted the young whydah as their own. 436 00:39:39,000 --> 00:39:42,040 And the more it begs, the more they give it. 437 00:40:03,040 --> 00:40:07,280 One last meal from its luckless foster parents… 438 00:40:13,480 --> 00:40:17,400 and the young whydah leaves its nest-mates behind. 439 00:40:29,360 --> 00:40:32,280 And this is what it will grow up to be, 440 00:40:32,840 --> 00:40:36,760 quite different from the hardworking waxbills that raised it. 441 00:40:39,440 --> 00:40:42,560 All pin-tailed whydahs are reared like this. 442 00:40:43,520 --> 00:40:45,160 Mimicry wins. 443 00:40:52,200 --> 00:40:55,160 Deceiving a different species is one thing, 444 00:40:55,240 --> 00:40:56,800 but in South Africa, 445 00:40:56,880 --> 00:41:01,160 one animal uses mimicry to fool its own kind. 446 00:41:04,080 --> 00:41:07,200 The Orange River, the largest in South Africa. 447 00:41:08,440 --> 00:41:11,400 And on it, the Augrabies Falls. 448 00:41:13,920 --> 00:41:15,920 [whimsical orchestral music playing] 449 00:41:17,080 --> 00:41:20,640 These are the main home of a particular species 450 00:41:20,720 --> 00:41:22,520 of flat-backed lizards. 451 00:41:26,520 --> 00:41:29,360 The males are brilliantly coloured. 452 00:41:35,600 --> 00:41:38,880 The females, on the other hand, are very different. 453 00:41:44,280 --> 00:41:46,680 They are plain and drab. 454 00:41:50,280 --> 00:41:52,560 The brilliance of a male's colours 455 00:41:52,640 --> 00:41:56,160 is an indication of its physical fitness and strength. 456 00:42:00,960 --> 00:42:04,160 The higher their status, the more colourful they are. 457 00:42:06,600 --> 00:42:10,640 And they're not afraid to make their seniority quite clear. 458 00:42:18,440 --> 00:42:19,920 A side-shuffle dance, 459 00:42:20,000 --> 00:42:21,520 showing off their colours, 460 00:42:21,600 --> 00:42:24,600 is usually quite enough to settle who is the boss. 461 00:42:27,120 --> 00:42:28,600 But if that doesn't work, 462 00:42:29,320 --> 00:42:30,320 they fight. 463 00:42:44,520 --> 00:42:47,640 Their disputes are all about location. 464 00:42:51,960 --> 00:42:55,680 Sometimes, they want a vantage point from which to show off. 465 00:42:56,760 --> 00:42:59,200 At others, a good place to hide. 466 00:42:59,920 --> 00:43:03,480 Or to get close to the river, where there's food. 467 00:43:07,040 --> 00:43:08,800 Here on these falls, 468 00:43:08,880 --> 00:43:11,200 food means flies. 469 00:43:15,520 --> 00:43:18,840 The river is a breeding ground for blackflies. 470 00:43:18,920 --> 00:43:20,800 There are huge swarms of them. 471 00:43:20,880 --> 00:43:22,080 [flies buzzing] 472 00:43:22,160 --> 00:43:26,160 And they are the favorite food of the lizards. 473 00:43:30,880 --> 00:43:34,000 They have acrobatic skills needed to catch them. 474 00:44:00,680 --> 00:44:03,680 While the colourful males are busy feeding, 475 00:44:04,440 --> 00:44:07,480 a different kind of male appears. 476 00:44:07,560 --> 00:44:09,880 [mysterious orchestral music playing] 477 00:44:09,960 --> 00:44:12,840 He is brown, rather like a female. 478 00:44:18,120 --> 00:44:21,160 There's just a hint of blue on his throat 479 00:44:21,240 --> 00:44:23,480 that gives him away as a male. 480 00:44:29,200 --> 00:44:30,880 He's fully mature, 481 00:44:30,960 --> 00:44:34,800 but not yet strong enough to compete with his flashier neighbours. 482 00:44:37,080 --> 00:44:38,200 To avoid fighting, 483 00:44:38,280 --> 00:44:41,560 he delays the development of his colours 484 00:44:41,640 --> 00:44:43,680 and so mimics a female. 485 00:44:44,640 --> 00:44:47,880 One in ten young males behave in this way. 486 00:44:49,680 --> 00:44:51,840 But he still needs to eat, 487 00:44:51,920 --> 00:44:53,160 and to do that, 488 00:44:53,240 --> 00:44:56,120 he's got to get down to the river, where the flies are. 489 00:44:57,680 --> 00:45:02,120 That means getting past the powerful, highly coloured males. 490 00:45:03,760 --> 00:45:06,280 [jaunty orchestral music playing] 491 00:45:09,720 --> 00:45:12,520 One thing could reveal the deception. 492 00:45:13,040 --> 00:45:14,920 He may look like a female, 493 00:45:15,000 --> 00:45:17,040 but he smells like a male. 494 00:45:23,760 --> 00:45:25,720 As long as he keeps his distance, 495 00:45:25,800 --> 00:45:27,040 he'll be all right. 496 00:45:30,600 --> 00:45:34,200 The big male hasn't noticed that he's not a female. 497 00:45:52,040 --> 00:45:53,120 Almost there. 498 00:45:55,880 --> 00:45:59,080 Only one male now stands in his way. 499 00:46:02,600 --> 00:46:05,200 The most dominant and aggressive of the lot. 500 00:46:05,760 --> 00:46:07,800 [tense orchestral music playing] 501 00:46:10,880 --> 00:46:12,280 [jaunty orchestral music playing] 502 00:46:28,600 --> 00:46:29,720 He's made it. 503 00:46:31,240 --> 00:46:32,720 His disguise worked, 504 00:46:32,800 --> 00:46:35,960 and now he can feast on the flies. 505 00:46:55,360 --> 00:46:57,880 He won't be able to keep this up forever. 506 00:46:57,960 --> 00:47:02,360 Ultimately, all males have to put on their glad rags 507 00:47:02,440 --> 00:47:06,280 and develop those bright colours if they are to breed. 508 00:47:11,480 --> 00:47:15,520 For now, though, he's developed a disguise that enables him to cheat 509 00:47:15,600 --> 00:47:18,960 in one of nature's most colour-dependent mating systems. 510 00:47:24,880 --> 00:47:28,440 So animals of all kinds use colour 511 00:47:28,520 --> 00:47:30,880 in a multitude of different ways. 512 00:47:32,920 --> 00:47:36,000 New discoveries are giving us fresh insights 513 00:47:36,080 --> 00:47:38,520 into the lives of these animals. 514 00:47:39,520 --> 00:47:43,640 And new cameras are allowing us to see into a world of colour 515 00:47:43,720 --> 00:47:45,280 as never before. 516 00:47:45,800 --> 00:47:48,000 [sweeping orchestral music playing] 517 00:47:59,040 --> 00:48:03,240 We're only just beginning to understand the many different ways 518 00:48:03,320 --> 00:48:05,200 in which animals use colour, 519 00:48:05,920 --> 00:48:09,560 particularly those colours that we can't even see. 520 00:48:15,760 --> 00:48:16,720 For us, 521 00:48:16,800 --> 00:48:21,840 colour in the natural world is a source of beauty and wonder, 522 00:48:22,560 --> 00:48:26,040 but for animals, it's a tool for survival. 523 00:48:38,360 --> 00:48:41,640 The story of Life in Colour continues. 524 00:48:42,600 --> 00:48:46,400 We delve even deeper into the lives of these animals 525 00:48:46,480 --> 00:48:50,640 and discover how science cracks the code of colour 526 00:48:50,720 --> 00:48:54,480 to see into a world that is invisible to us… 527 00:48:55,000 --> 00:48:57,360 [man] Look at that. That's extraordinary. 528 00:48:58,400 --> 00:49:02,840 [Attenborough] …revealing the hidden secrets of Life in Colour.