1 00:00:01,360 --> 00:00:02,634 LIGHT CHEERFUL MUSIC 2 00:00:03,280 --> 00:00:06,477 The natural world is full of extraordinary animals 3 00:00:07,120 --> 00:00:09,077 with amazing life histories, 4 00:00:09,920 --> 00:00:13,072 yet certain stories are more intriguing than others. 5 00:00:16,000 --> 00:00:18,833 The mysteries of a butterfly? fife cycle 6 00:00:19,040 --> 00:00:22,078 or the strange biology of the Emperor penguin. 7 00:00:23,240 --> 00:00:27,313 Some of these creatures were surrounded by fantastic myths 8 00:00:27,440 --> 00:00:28,999 and misunderstandings. 9 00:00:30,600 --> 00:00:33,911 Others have only recently re vealed their secrets. 10 00:00:35,200 --> 00:00:38,875 These are the creatures that stand out from the crowd. 11 00:00:39,040 --> 00:00:43,159 The curiosities that I find particuiarly fascinating. 12 00:00:47,680 --> 00:00:49,000 MUSIC FADES TO SILENCE 13 00:00:51,760 --> 00:00:53,034 EERIE MUSIC 14 00:00:54,360 --> 00:00:58,035 In this programme, we investigate the stories of two animals 15 00:00:58,160 --> 00:01:01,152 that owe their existence to human interference. 16 00:01:02,080 --> 00:01:04,720 Killer bees that were created accidentally 17 00:01:04,880 --> 00:01:08,077 when a wet! meaning breeding experiment went wrong. 18 00:01:09,560 --> 00:01:11,471 And pizzly bears; 19 00:01:11,720 --> 00:01:15,111 the resuit of polar bears and brown bears interbreeding. 20 00:01:16,320 --> 00:01:19,199 How were these strange animals created 21 00:01:19,600 --> 00:01:24,276 and are they unnatural mutants or valuable new hybrids? 22 00:01:26,280 --> 00:01:28,590 This is a grizzly bear. 23 00:01:29,640 --> 00:01:33,076 And that white one there is, of course, a polar bear. 24 00:01:33,800 --> 00:01:37,395 But in between, there's a different kind of bear. 25 00:01:38,240 --> 00:01:41,790 It's got the white coat of a polar bear, 26 00:01:41,920 --> 00:01:45,197 except that, around the eyes, it's rather brown. 27 00:01:46,120 --> 00:01:48,999 And its front legs are very brown. 28 00:01:49,800 --> 00:01:51,757 It is, in fact, a hybrid. 29 00:01:51,960 --> 00:01:55,635 The result of a mating between a polar bear and a grizzly bear. 30 00:01:55,920 --> 00:01:58,594 And it's sometimes called a pizzly. 31 00:02:01,600 --> 00:02:07,073 The first ever pizzty bears were born in a German zoo in 1876 32 00:02:07,200 --> 00:02:10,750 after a polar bear and a grizzly, a type of brown bear, 33 00:02:10,880 --> 00:02:12,279 were housed together. 34 00:02:14,000 --> 00:02:17,197 Hybrid animals have frequently been born in captivity, 35 00:02:17,360 --> 00:02:19,670 both intentionally and by accident. 36 00:02:20,760 --> 00:02:23,957 Tigers and lions produce offspring catted Iigers 37 00:02:24,680 --> 00:02:28,389 and donkeys and zebra babies known as zonkeys. 38 00:02:29,000 --> 00:02:31,640 But usually these hybrid creatures are sterile 39 00:02:31,800 --> 00:02:34,758 and are not well adapted for surviving in the wiid. 40 00:02:37,000 --> 00:02:40,391 Animals, of course, usually mate with their own kind. 41 00:02:41,840 --> 00:02:46,118 If different species are to interbreed and produce fertile young 42 00:02:46,520 --> 00:02:49,399 they have to be extremely closely related. 43 00:02:51,480 --> 00:02:53,517 Grizzly bear and polar bears 44 00:02:53,680 --> 00:02:56,433 are certainly somewhat similar in appearance, 45 00:02:57,560 --> 00:03:00,234 but are they, in fact, closely related? 46 00:03:03,760 --> 00:03:07,151 In the bear family, the black species came first, 47 00:03:07,320 --> 00:03:11,598 and then came the brown bear, and finally, the white polar bear. 48 00:03:12,440 --> 00:03:16,399 This was thought to have happened about 4 to 5 million years ago, 49 00:03:16,520 --> 00:03:20,479 but recent fossil evidence suggests that it may have happened as recently 50 00:03:20,640 --> 00:03:22,790 as only half a million years ago. 51 00:03:26,120 --> 00:03:29,875 So the polar bear is a relative/y recent species of bear. 52 00:03:30,760 --> 00:03:34,071 One that branched off late in the bear family tree. 53 00:03:36,560 --> 00:03:37,959 GENTLE MUSIC 54 00:03:39,040 --> 00:03:42,749 Polar bears live high in the Arctic and are true carnivores. 55 00:03:43,520 --> 00:03:46,319 They're slightly bigger in size than brown bears. 56 00:03:47,040 --> 00:03:50,795 Their fur is creamy white, unlike the reddish brown grizzly, 57 00:03:51,240 --> 00:03:54,790 not surprisingly, since they five in very different habitats. 58 00:03:56,680 --> 00:04:00,275 Grizzly bears are found in North America and Northern Europe. 59 00:04:01,120 --> 00:04:05,717 They're omnivores and eat some meat, nuts, grass and fruit. 60 00:04:08,080 --> 00:04:10,640 Grizzly bears have rounded heads 61 00:04:10,760 --> 00:04:14,594 and prominent shoulder humps that have evolved for digging. 62 00:04:15,960 --> 00:04:17,712 Polar bears, on the other hand, 63 00:04:17,880 --> 00:04:21,839 have more pointed heads, but no shoulder humps. 64 00:04:22,720 --> 00:04:25,473 Their feet have hairy pads and short claws, 65 00:04:25,680 --> 00:04:28,274 which helps to prevent them slipping on ice. 66 00:04:28,920 --> 00:04:31,639 The grizzly has more obvious footpads 67 00:04:31,800 --> 00:04:34,189 and much larger, curved claws. 68 00:04:36,040 --> 00:04:39,556 We know that polar and grizzly bears can mate successfully, 69 00:04:39,720 --> 00:04:42,075 but what sort of offspring do they produce? 70 00:04:43,400 --> 00:04:48,110 For many years, zoos discouraged the breeding of pizz§y bears, 71 00:04:48,600 --> 00:04:52,230 but recently there was a chance to study them in Germany. 72 00:04:53,400 --> 00:04:56,836 In 2004, at Osnabruck Zoo, 73 00:04:57,080 --> 00:05:00,755 a brown bear called Susi and a polar bear called Elvis 74 00:05:00,920 --> 00:05:03,560 who'd shared an enclosure for 24 years, 75 00:05:03,720 --> 00:05:06,109 unexpectedly produced wins. 76 00:05:06,640 --> 00:05:10,520 The small brown cubs are bigger now and have changed colour. 77 00:05:11,680 --> 00:05:14,354 The male, named Tapps, is brown, 78 00:05:15,240 --> 00:05:18,710 and the female, Tipps, has a tighter coat. 79 00:05:19,840 --> 00:05:23,117 But otherwise, they have traits inherited from both parents. 80 00:05:24,120 --> 00:05:28,353 Long necks and visible tails, that are more typical of polar bears, 81 00:05:29,480 --> 00:05:31,471 but also small shoulder humps 82 00:05:31,640 --> 00:05:34,712 that are reminiscent of those of brown bears. 83 00:05:36,240 --> 00:05:39,039 Their feet are intermediate in form 84 00:05:39,640 --> 00:05:42,029 and their size is between the two, 85 00:05:42,280 --> 00:05:46,274 smaller than a polar bear, but larger than a brown bear. 86 00:05:50,920 --> 00:05:52,752 We know from Osnabruck Zoo 87 00:05:53,120 --> 00:05:55,316 that when polar bears and grizzlies mate 88 00:05:55,560 --> 00:05:58,439 they can produce pizziy cubs. 89 00:05:58,880 --> 00:06:01,793 But what are the chances of these very different bears 90 00:06:01,960 --> 00:06:03,553 meeting in the wild? 91 00:06:05,200 --> 00:06:08,989 This is the grizzly bear's home range in North America. 92 00:06:09,680 --> 00:06:12,274 Polar bears live higher up in the Arctic 93 00:06:12,480 --> 00:06:14,596 so the two species are neighbours, 94 00:06:14,760 --> 00:06:17,798 but ones with very different lifestyles and feeding habits 95 00:06:17,960 --> 00:06:19,837 that restrict their ranges. 96 00:06:22,920 --> 00:06:24,752 But their habitats are changing 97 00:06:25,040 --> 00:06:26,758 as the climate is warming 98 00:06:28,120 --> 00:06:31,238 and that's beginning to have an effect on the behaviour 99 00:06:31,400 --> 00:06:33,789 of the two species in the wild. 100 00:06:34,960 --> 00:06:36,633 In 2003, 101 00:06:37,120 --> 00:06:39,589 a researcher working on a remote island 102 00:06:39,760 --> 00:06:41,592 between Church?“ and the North Pole 103 00:06:41,920 --> 00:06:45,117 discovered strange bear footprints in the snow 104 00:06:45,360 --> 00:06:47,351 together with brown hairs. 105 00:06:47,760 --> 00:06:51,469 The hair came from a grizziy. This was extraordinary. 106 00:06:52,000 --> 00:06:55,231 The grizzly must have strayed hundreds of miles from its home 107 00:06:55,520 --> 00:06:58,034 and travetied deep into polar bear territory. 108 00:06:58,800 --> 00:07:00,029 So it was clear 109 00:07:00,200 --> 00:07:03,750 that the chances of these cousins meeting and mating in the wild 110 00:07:03,880 --> 00:07:06,190 was becoming a real possibility. 111 00:07:07,200 --> 00:07:09,316 But would their offspring survive? 112 00:07:10,120 --> 00:07:14,717 Research on captive pizzly bears suggested that they could. 113 00:07:16,440 --> 00:07:20,035 The hair of brown bear, polar bear and pizzly bear 114 00:07:20,200 --> 00:07:23,431 are quite different, not only in colour, but in structure. 115 00:07:24,200 --> 00:07:27,238 Here are cross sections of a hair from each of them. 116 00:07:27,600 --> 00:07:29,830 The brown bear has a central canal, 117 00:07:30,000 --> 00:07:32,640 which is filled with a honeycomb structure. 118 00:07:33,200 --> 00:07:35,840 The polar bear, that central canal is almost empty, 119 00:07:36,000 --> 00:07:38,514 making that hair good for insulation, 120 00:07:38,800 --> 00:07:41,189 just what you need in a cold climate. 121 00:07:41,440 --> 00:07:45,559 And the pizzly bear is a sort of compromise between the two. 122 00:07:45,880 --> 00:07:49,475 The central canal has just a little in filling, so you might say 123 00:07:49,680 --> 00:07:53,878 that it's not bad for cold temperatures and not bad for warm. 124 00:07:54,920 --> 00:07:56,274 GENTLE INNOCENT MUSIC 125 00:07:56,560 --> 00:08:00,030 Possessing a mix of characteristics of both parent bears 126 00:08:00,240 --> 00:08:05,076 could actually help the hybrids survive in a rapidly changing world. 127 00:08:06,720 --> 00:08:09,838 Their hunting ski/ls have also become more variable. 128 00:08:10,640 --> 00:08:14,349 Tlpps and Tapps sometimes fish like brown bears, 129 00:08:14,560 --> 00:08:17,279 but at other times behave like poiar bears. 130 00:08:18,640 --> 00:08:20,278 Stamping, for instance. 131 00:08:20,680 --> 00:08:24,958 Polar bears push down on ice to break it during their search for seals. 132 00:08:25,120 --> 00:08:28,511 The Osnabruck pizziies perform a similar action. 133 00:08:30,960 --> 00:08:34,590 This mixture of physical and behavioural characteristics 134 00:08:34,760 --> 00:08:38,549 suggest that pizzties may be we?! equipped to survive in the wild 135 00:08:38,720 --> 00:08:41,838 if conditions in the Arctic continue to change. 136 00:08:44,280 --> 00:08:48,672 And in 2006, this notion became reality. 137 00:08:49,240 --> 00:08:51,356 An odd-looking bear was shot 138 00:08:51,520 --> 00:08:54,273 during a polar bear hunt in Northern Canada. 139 00:08:54,920 --> 00:08:59,835 It was small, hunched and had dark smudges around its eyes and muzzle. 140 00:09:01,800 --> 00:09:05,270 DNA testing showed that its mother was a polar bear 141 00:09:05,480 --> 00:09:08,598 and its father a grizzly that had traveiied further north 142 00:09:08,760 --> 00:09:11,798 and was hundreds of miles beyond its normal range. 143 00:09:15,120 --> 00:09:19,478 So pizzly bears aren't just the result of captive breeding. 144 00:09:20,080 --> 00:09:23,198 Several have been reliably identified in the wild, 145 00:09:23,360 --> 00:09:26,193 though none have yet been caught alive. 146 00:09:26,880 --> 00:09:30,714 But as the climate warms, so brown bears are moving north 147 00:09:30,880 --> 00:09:32,678 and polar bears coming south. 148 00:09:33,280 --> 00:09:35,430 And their close genetic relationship 149 00:09:35,800 --> 00:09:38,076 means that not only can they interbreed, 150 00:09:38,720 --> 00:09:42,270 but the offspring are likely to be fertile. 151 00:09:44,560 --> 00:09:48,155 The ranges of these bears are now increasingly overlapping. 152 00:09:48,760 --> 00:09:49,830 SEAGULL CRIES 153 00:09:50,040 --> 00:09:54,796 It's now not uncommon to see polar and grizzly bears feasting together 154 00:09:54,960 --> 00:09:59,193 when there's plenty of meat around as there is after a whale hunt. 155 00:10:00,680 --> 00:10:05,800 So are we seeing a new development in the evolutionary history of bears? 156 00:10:06,760 --> 00:10:11,789 In April 2010, biologists in the Northwest Territories of Canada 157 00:10:11,960 --> 00:10:14,156 shot a dangerous polar bear. 158 00:10:14,880 --> 00:10:16,632 It was strange in appearance 159 00:10:16,800 --> 00:10:19,792 and DNA analysis showed something very significant. 160 00:10:20,360 --> 00:10:24,274 This was a second generation pizzly bear. 161 00:10:24,680 --> 00:10:28,674 The result of a female grizzly mating with a polar bear. 162 00:10:29,200 --> 00:10:33,433 As global warming continues to diminish the Arctic sea ice habitat, 163 00:10:33,600 --> 00:10:36,069 climate scientists believe that the polar bear 164 00:10:36,240 --> 00:10:38,754 will struggle to survive as a species. 165 00:10:39,120 --> 00:10:43,034 But at least some of the polar bear traits will be preserved 166 00:10:43,200 --> 00:10:45,874 in these strange-looking hybrids. 167 00:10:47,600 --> 00:10:52,993 So pizziy bears are not bizarre Frankenstein-iike creatures. 168 00:10:53,240 --> 00:10:57,029 They're valuable new hybrids that may become increasingly common. 169 00:11:00,040 --> 00:11:02,509 Next, the story of a familiar creature 170 00:11:02,680 --> 00:11:04,990 that had a shocking change of character 171 00:11:05,240 --> 00:11:09,234 when a well-meaning experiment went disastrously wrong 172 00:11:09,400 --> 00:11:12,518 and created a hybrid killer bee. 173 00:11:13,480 --> 00:11:14,754 SHRILL MUSIC 174 00:11:15,360 --> 00:11:16,680 BEES BUZZING 175 00:11:16,960 --> 00:11:21,591 In the 1960s and 70s, bees hit the headlines. 176 00:11:24,280 --> 00:11:27,557 Huge swarms were attacking people and livestock 177 00:11:27,720 --> 00:11:29,393 for no apparent reason. 178 00:11:32,280 --> 00:11:36,069 The bees launching these attacks were, in fact, honey bees. 179 00:11:36,480 --> 00:11:39,711 The sort from which we've been collecting honey for centuries. 180 00:11:42,160 --> 00:11:45,915 In the Western world, monks traditionally kept bees for honey 181 00:11:46,520 --> 00:11:49,717 and for the wax that they used to make candles. 182 00:11:50,560 --> 00:11:54,190 For centuries, bees have had an association with human beings 183 00:11:54,360 --> 00:11:58,354 and passive, easy-to-handle bees have been selectively bred. 184 00:11:58,760 --> 00:12:03,675 So the European honey bee became a tolerant, well-tempered bee. 185 00:12:04,920 --> 00:12:06,149 BEES BUZZING 186 00:12:07,440 --> 00:12:10,080 So why would a species of bee 187 00:12:10,240 --> 00:12:13,631 that has lived amiably alongside people for so long 188 00:12:13,800 --> 00:12:15,677 suddenly change its nature? 189 00:12:16,720 --> 00:12:21,237 The temperament of a bee colony is determined by that of the queen bee. 190 00:12:21,400 --> 00:12:24,279 The one seen here marked with the blue spot. 191 00:12:24,440 --> 00:12:27,319 She fays aft the eggs in the hive. 192 00:12:28,520 --> 00:12:32,036 An aggressive queen will produce very ferocious workers, 193 00:12:32,200 --> 00:12:35,397 while a passive queen produces calmer ones. 194 00:12:36,520 --> 00:12:40,150 European honey bees are generally very passive. 195 00:12:42,840 --> 00:12:44,194 TENSE MUSIC 196 00:12:46,920 --> 00:12:49,480 African bees, however, are very different. 197 00:12:50,880 --> 00:12:55,511 They have evolved to sting and attack large predators that raid their nests. 198 00:12:58,800 --> 00:13:01,360 And to defend themselves from man, 199 00:13:01,520 --> 00:13:03,670 who disturbs them when collecting honey. 200 00:13:07,600 --> 00:13:09,955 Nonetheless, they're very hardworking. 201 00:13:10,880 --> 00:13:13,633 They manage to produce substantial quantities of honey 202 00:13:13,800 --> 00:13:15,074 in dry habitats 203 00:13:15,240 --> 00:13:18,790 where good quality flowers are often hard to find. 204 00:13:22,080 --> 00:13:26,119 In the 1950s, honey production in Brazil was failing. 205 00:13:27,360 --> 00:13:31,035 And it was thought that African bees might be abte to help. 206 00:13:34,960 --> 00:13:38,430 So a Brazilian scientist, Dr Warrick Kerr, 207 00:13:38,600 --> 00:13:41,752 who was a specialist in bee genetics, was consulted. 208 00:13:43,080 --> 00:13:46,072 The Brazilian Ministry of Agriculture asked Kerr 209 00:13:46,320 --> 00:13:49,915 if he could obtain some African queens to experiment with 210 00:13:50,360 --> 00:13:55,150 in order to breed a bee that combined the passive nature of the European bee 211 00:13:55,320 --> 00:13:58,551 with the higher productivity of the African bee. 212 00:13:59,240 --> 00:14:01,595 The bees there had originated from stock 213 00:14:01,760 --> 00:14:05,355 imported to North America by British colonists. 214 00:14:05,840 --> 00:14:08,593 Although these bees were productive in the North, 215 00:14:08,760 --> 00:14:11,513 the more tropical climate of Central and South America 216 00:14:11,680 --> 00:14:13,353 didn't suit them so well. 217 00:14:13,840 --> 00:14:16,036 Here, they were not so productive. 218 00:14:16,320 --> 00:14:17,913 BIRDS SINGING AND BEES BUZZING 219 00:14:19,160 --> 00:14:22,391 European honey bees normally live in temperate climates 220 00:14:22,720 --> 00:14:26,509 where an abundance of flowering plants provide a lot of nectar. 221 00:14:28,320 --> 00:14:31,073 So they're able to produce honey quite easily. 222 00:14:32,400 --> 00:14:33,959 GENTLE TENSE MUSIC 223 00:14:35,120 --> 00:14:37,839 But conditions were not like that in Brazil 224 00:14:38,000 --> 00:14:42,153 and the European bees struggled to make honey in any quantity. 225 00:14:43,400 --> 00:14:46,074 The habits of the African bee seemed more suited 226 00:14:46,240 --> 00:14:47,992 to the South American climate. 227 00:14:49,440 --> 00:14:52,319 Honey bees are very choosy feeders. 228 00:14:52,680 --> 00:14:57,436 They will carefully select those flowers that have the strongest nectar, 229 00:14:57,640 --> 00:15:00,359 the sweetest nectar, and I can demonstrate that. 230 00:15:00,640 --> 00:15:03,632 Here is a little bee in a bee holder. 231 00:15:03,840 --> 00:15:05,592 Let me first try her 232 00:15:06,120 --> 00:15:08,794 with a dilute solution of sugar. 233 00:15:11,320 --> 00:15:12,435 No reaction. 234 00:15:14,400 --> 00:15:17,870 Now let me try her with a stronger solution. 235 00:15:18,040 --> 00:15:19,394 A sweeter solution. 236 00:15:22,720 --> 00:15:24,518 And out comes her proboscis. 237 00:15:27,600 --> 00:15:28,715 It won't let go! 238 00:15:30,160 --> 00:15:31,195 DAVID LAUGHS 239 00:15:32,760 --> 00:15:36,071 Western European bees can afford to be choosy 240 00:15:36,480 --> 00:15:39,757 because there's flowers with rich nectar available 241 00:15:39,920 --> 00:15:42,070 for such a long period of time. 242 00:15:42,320 --> 00:15:44,960 African bees have no such luxury. 243 00:15:45,360 --> 00:15:49,672 They have to feed at times when there are very few flowers open anyway 244 00:15:49,840 --> 00:15:52,912 and those that are, are not very rich in nectar. 245 00:15:53,080 --> 00:15:55,720 So they are much more industrious. 246 00:15:56,080 --> 00:15:57,354 Let's release you 247 00:15:58,120 --> 00:16:02,956 so you can go back and collect some more nectar. 248 00:16:06,560 --> 00:16:07,880 BEE BUZZES 249 00:16:08,680 --> 00:16:09,715 It's gone. 250 00:16:12,120 --> 00:16:16,159 Kerr planned to take the industrious, less fussy African bee 251 00:16:16,320 --> 00:16:19,073 and combine it with the passive European bee 252 00:16:19,240 --> 00:16:23,029 to produce one that would work hard but would not be aggressive. 253 00:16:23,440 --> 00:16:26,910 He persuaded particularly successful African beekeepers 254 00:16:27,080 --> 00:16:30,516 to let him have some of their most gentle and passive queens, 255 00:16:30,680 --> 00:16:32,876 133 in all. 256 00:16:33,560 --> 00:16:38,999 Unfortunately, a customs agent sprayed his bees with insecticide 257 00:16:39,160 --> 00:16:40,389 and they all died. 258 00:16:42,440 --> 00:16:44,829 Kerr then chose a second batch, 259 00:16:45,000 --> 00:16:48,959 but this time, he didn't screen out the most aggressive bees. 260 00:16:49,440 --> 00:16:52,080 47 of these queens survived, 261 00:16:52,360 --> 00:16:56,593 but they were far too fierce to give to the local Brazilian beekeepers. 262 00:16:56,920 --> 00:17:01,232 So Kerr decided to breed them with some with some gentler drones. 263 00:17:02,920 --> 00:17:06,629 Doctor Kerr set up 35 colonies 264 00:17:06,800 --> 00:17:11,192 in an isolated area of Eucalyptus forest near Sao Paolo. 265 00:17:11,800 --> 00:17:14,758 And to prevent the queens from escaping 266 00:17:15,200 --> 00:17:18,875 he used a device called a queen excluder. 267 00:17:19,920 --> 00:17:22,992 It fits on top of the brood box here. 268 00:17:23,680 --> 00:17:29,312 The bars are sufficiently wide apart to allow worker bees to pass through, 269 00:17:29,560 --> 00:17:32,313 but not so wide that the queen can. 270 00:17:32,560 --> 00:17:36,713 But he went away and you can't cater for human error. 271 00:17:37,560 --> 00:17:40,439 In his absence, a local beekeeper came 272 00:17:40,720 --> 00:17:43,189 and noticed that the worker bees passing through 273 00:17:43,360 --> 00:17:46,432 were losing some of the pollen that they'd collected. 274 00:17:46,920 --> 00:17:49,309 So he removed the queen excluders. 275 00:17:49,840 --> 00:17:52,639 And by the time Doctor Kerr came back, 276 00:17:53,400 --> 00:17:57,030 26 of the queens had escaped into the wild, 277 00:17:57,440 --> 00:17:59,033 and were already swarming. 278 00:18:01,000 --> 00:18:05,198 Swarming is the way bees naturally increase their population. 279 00:18:06,480 --> 00:18:10,360 A queen bee leaves the hive, taking many of the workers with her. 280 00:18:10,520 --> 00:18:11,749 A swarm gathers, 281 00:18:11,920 --> 00:18:15,709 rests, and quickly relocates to form a new colony. 282 00:18:17,360 --> 00:18:20,910 African bees swarm more than their European cousins 283 00:18:21,080 --> 00:18:24,789 and frequently divide to form mu/t/irale colonies. 284 00:18:26,520 --> 00:18:29,911 Kerri; escaped queens and the Aifloanised worker bees 285 00:18:30,080 --> 00:18:32,196 inherited this tendency to swarm 286 00:18:32,520 --> 00:18:35,478 and they spread quickly across South America. 287 00:18:36,120 --> 00:18:37,235 BEES BUZZING 288 00:18:38,040 --> 00:18:39,314 WIND BLOWING 289 00:18:41,880 --> 00:18:45,669 It was assumed that the abundant native European bees 290 00:18:45,840 --> 00:18:49,993 would weaken the escaped African bees' more aggressive nature, 291 00:18:50,120 --> 00:18:51,554 but this didn't happen. 292 00:18:52,040 --> 00:18:56,193 The African genes were strong and their behaviour dominated. 293 00:18:57,000 --> 00:19:02,074 By 1965, most Brazilian hives had been devastated 294 00:19:02,440 --> 00:19:06,752 and the aggressive Africanised bees swept their way through South America 295 00:19:06,920 --> 00:19:09,389 and headed up into North America. 296 00:19:11,400 --> 00:19:14,472 They started to attack people with little provocation 297 00:19:14,640 --> 00:19:16,756 and sometimes fate! results. 298 00:19:19,440 --> 00:19:22,353 Up to 90% of a colony would launch an attack 299 00:19:22,520 --> 00:19:26,400 and even though their venom was no more potent than the European bee, 300 00:19:26,560 --> 00:19:28,631 they sting in their thousands. 301 00:19:29,880 --> 00:19:31,279 TENSE MUSIC 302 00:19:31,520 --> 00:19:36,071 Horror movies pictured them as crazed killers with lethal stings. 303 00:19:38,480 --> 00:19:40,676 But this was far from the truth. 304 00:19:41,280 --> 00:19:45,069 In any case, it wasn't the African Dee's sting that was fatal, 305 00:19:45,240 --> 00:19:46,639 it was their behaviour. 306 00:19:48,520 --> 00:19:51,512 The escape of such aggressive bees in the wild 307 00:19:51,680 --> 00:19:54,240 was devastating for Kerr's career. 308 00:19:55,000 --> 00:19:58,959 Africanised bees spread as far as the lower parts of North America, 309 00:19:59,440 --> 00:20:01,590 but here, their takeover hatted. 310 00:20:02,200 --> 00:20:04,635 The more temperate climate didn't suit them. 311 00:20:05,760 --> 00:20:06,909 TENSE MUSIC LIGHTENS 312 00:20:08,680 --> 00:20:10,591 Kerfs intentions had been good 313 00:20:11,120 --> 00:20:14,829 and he later dedicated his research to try and correct the probiem. 314 00:20:17,680 --> 00:20:22,038 Eventually, Kerr did help to create productive, more passive bee, 315 00:20:22,520 --> 00:20:24,557 as had originally been his plan. 316 00:20:25,520 --> 00:20:29,832 And South America is now one of the world's largest exporters of honey. 317 00:20:32,960 --> 00:20:34,189 MUSIC FADES 318 00:20:34,840 --> 00:20:39,198 The creation of the so-called killer bee by Doctor Kerr's experiments 319 00:20:39,400 --> 00:20:41,550 was indeed a grave mistake. 320 00:20:42,320 --> 00:20:48,111 But in recent years a more gentle form of African bee has been bred 321 00:20:49,040 --> 00:20:53,955 and it's also possible that the ferocity of the African bee 322 00:20:54,360 --> 00:20:56,636 has now been turned to our advantage. 323 00:20:57,440 --> 00:21:00,831 Elephants are said to be terrified of bees 324 00:21:01,360 --> 00:21:04,352 and in recent years farmers in Africa 325 00:21:04,520 --> 00:21:08,832 have started playing the sounds of swarming bees over their fields 326 00:21:09,200 --> 00:21:11,350 and the elephants have kept away. 327 00:21:11,960 --> 00:21:16,875 So, as well as pollinating plants, bees can actually protect them. 328 00:21:18,880 --> 00:21:24,637 So both the Africahised honey bee and the pizzly bear are here to stay. 329 00:21:25,080 --> 00:21:27,993 But these unusual hybrids owe their success, 330 00:21:28,160 --> 00:21:30,913 in one way or another, to humans.