1 00:00:23,941 --> 00:00:26,819 When scientists first arrived at Ngogo... 2 00:00:31,949 --> 00:00:34,744 ...they discovered an advanced chimpanzee society. 3 00:00:47,465 --> 00:00:49,926 Over the decades, that society 4 00:00:50,760 --> 00:00:53,721 grew to become the biggest chimp group 5 00:00:54,263 --> 00:00:55,473 ever known. 6 00:00:56,682 --> 00:00:58,184 They expanded their territory, 7 00:00:59,852 --> 00:01:01,354 dominated the forest, 8 00:01:02,647 --> 00:01:05,191 and built an empire. 9 00:01:14,075 --> 00:01:16,077 But rivalries developed, 10 00:01:17,537 --> 00:01:19,956 and the empire divided. 11 00:01:23,960 --> 00:01:27,964 A small but powerful band of males broke away to form their own group. 12 00:01:29,924 --> 00:01:30,967 They became... 13 00:01:32,885 --> 00:01:34,011 the westerners. 14 00:01:35,847 --> 00:01:38,266 Chimps that lived together for years... 15 00:01:39,684 --> 00:01:41,269 ...became enemies. 16 00:01:49,777 --> 00:01:51,028 And now... 17 00:01:53,030 --> 00:01:54,031 their rivalry 18 00:01:54,866 --> 00:01:56,159 has turned deadly. 19 00:02:26,606 --> 00:02:28,399 It's still just a few days 20 00:02:28,983 --> 00:02:30,818 since the central chimps 21 00:02:31,861 --> 00:02:33,237 found Pork Pie dead. 22 00:02:40,119 --> 00:02:42,830 It's not known what chimps understand about death... 23 00:02:45,333 --> 00:02:46,500 or whether they grieve. 24 00:02:51,172 --> 00:02:54,759 But the loss of Pork Pie has clearly had an impact. 25 00:03:01,098 --> 00:03:02,642 For the central chimps, 26 00:03:02,642 --> 00:03:05,603 the world has become more dangerous. 27 00:03:42,848 --> 00:03:45,476 Christine's baby is now nine months old. 28 00:03:50,940 --> 00:03:52,149 When she first arrived, 29 00:03:53,067 --> 00:03:55,903 her sister, Nadine, was neglected. 30 00:03:59,532 --> 00:04:00,950 Now she's a little older, 31 00:04:02,618 --> 00:04:04,787 and her personality is beginning to develop... 32 00:04:06,956 --> 00:04:09,292 she's begun to add to Nadine's life. 33 00:04:13,713 --> 00:04:14,964 They're not only sisters. 34 00:04:16,757 --> 00:04:18,175 They're best friends. 35 00:04:43,868 --> 00:04:46,203 Ngogo is never richer in food 36 00:04:46,203 --> 00:04:49,206 than when Chrysophyllum is in fruit. 37 00:04:50,458 --> 00:04:52,376 And it brings the chimps together. 38 00:05:19,487 --> 00:05:21,572 Jackson is still under pressure. 39 00:05:25,117 --> 00:05:27,203 Abrams is back in his place, 40 00:05:27,203 --> 00:05:29,121 but he won't give up. 41 00:05:32,666 --> 00:05:35,586 Jackson needs to remind everyone who is in charge. 42 00:06:31,434 --> 00:06:34,186 While Jackson is focused on dominating at home, 43 00:06:34,979 --> 00:06:38,357 other chimps are standing guard at the western border... 44 00:06:42,319 --> 00:06:44,196 alert to the new threat they face. 45 00:06:59,670 --> 00:07:00,838 Abrams is here. 46 00:07:03,299 --> 00:07:05,509 And so are several other adult males. 47 00:07:27,490 --> 00:07:29,617 But they have no way of knowing 48 00:07:29,617 --> 00:07:32,369 when the westerners will strike again. 49 00:08:00,314 --> 00:08:02,483 {\an8}The life of an alpha male isn't easy. 50 00:08:04,610 --> 00:08:06,070 But it comes with benefits. 51 00:08:08,697 --> 00:08:11,283 Generally, the higher a chimp's rank, 52 00:08:12,117 --> 00:08:14,537 the more opportunities they have to mate. 53 00:08:18,832 --> 00:08:20,876 Mature females like Bartoli 54 00:08:22,253 --> 00:08:25,130 normally give birth every five or six years. 55 00:09:08,716 --> 00:09:11,802 {\an8}Bartoli's son, Herzog, is six years old now, 56 00:09:14,263 --> 00:09:16,181 and she's ready to get pregnant again. 57 00:09:28,569 --> 00:09:30,946 She could do a lot worse than Jackson's genes. 58 00:09:32,865 --> 00:09:34,366 But she needs to be cautious. 59 00:09:38,078 --> 00:09:39,038 Jackson is big, 60 00:09:39,872 --> 00:09:42,041 powerful, and unpredictable. 61 00:09:45,252 --> 00:09:48,339 She needs to keep herself and Herzog safe... 62 00:09:51,342 --> 00:09:54,011 and ensure that Jackson is calm. 63 00:10:05,731 --> 00:10:08,150 Herzog finds the whole thing confusing. 64 00:10:14,657 --> 00:10:15,908 But as a young chimp, 65 00:10:15,908 --> 00:10:17,910 he has to stay close to his mother. 66 00:10:25,334 --> 00:10:26,585 Whatever she's doing. 67 00:10:56,615 --> 00:10:58,701 Jackson is making his move. 68 00:11:00,786 --> 00:11:02,079 By waving a branch, 69 00:11:02,955 --> 00:11:05,708 he's asking Bartoli to follow him... 70 00:11:08,293 --> 00:11:09,211 and mate. 71 00:11:32,109 --> 00:11:33,944 And Bartoli seems keen. 72 00:11:59,136 --> 00:12:02,097 - Herzog makes an attempt to break it up. 73 00:12:10,689 --> 00:12:11,774 But it's too late. 74 00:12:19,615 --> 00:12:21,158 Jackson got what he wanted. 75 00:12:26,789 --> 00:12:28,040 And so did Bartoli. 76 00:12:33,003 --> 00:12:34,630 But it's been a tiring day. 77 00:12:40,511 --> 00:12:43,764 Female chimps mate with multiple males. 78 00:12:43,764 --> 00:12:45,265 So there's no guarantee 79 00:12:45,265 --> 00:12:47,976 Jackson will be the father of Bartoli's baby. 80 00:12:52,314 --> 00:12:54,149 He stands a good chance though. 81 00:12:55,609 --> 00:12:57,152 Because it's happened before. 82 00:12:58,403 --> 00:13:00,197 Although Jackson doesn't know it, 83 00:13:01,740 --> 00:13:03,784 Herzog is his son. 84 00:13:34,481 --> 00:13:37,359 Chimps don't always hunt because they are hungry. 85 00:13:40,654 --> 00:13:43,615 In fact, usually the opposite is true. 86 00:13:46,660 --> 00:13:47,828 They hunt much more 87 00:13:47,828 --> 00:13:50,789 when they are well-fed and bursting with energy. 88 00:13:54,293 --> 00:13:56,420 When Chrysophyllum is in full fruit, 89 00:13:57,212 --> 00:13:59,840 hunting goes into overdrive. 90 00:14:28,118 --> 00:14:30,704 Chimpanzees don't conserve resources... 91 00:14:35,667 --> 00:14:38,295 or think about the nature of what they are eating. 92 00:14:48,305 --> 00:14:49,806 With this many kills, 93 00:14:50,474 --> 00:14:53,310 meat sharing is highly political. 94 00:15:03,236 --> 00:15:05,739 For Jackson, this big duiker 95 00:15:05,739 --> 00:15:08,408 is an opportunity to strengthen his position 96 00:15:09,076 --> 00:15:10,911 by sharing with his allies. 97 00:15:34,142 --> 00:15:37,771 Today, he's favoring another high-ranking male. 98 00:15:42,025 --> 00:15:43,026 Peterson. 99 00:15:52,411 --> 00:15:53,912 But just as important 100 00:15:53,912 --> 00:15:55,872 is who he's excluding. 101 00:16:29,281 --> 00:16:32,159 Wilson is an up-and-coming young male. 102 00:16:36,913 --> 00:16:37,956 He's strong, 103 00:16:38,623 --> 00:16:39,791 and he's ambitious. 104 00:16:42,169 --> 00:16:43,962 Jackson is not including him. 105 00:16:54,890 --> 00:16:56,475 And he's taking it badly. 106 00:17:16,703 --> 00:17:19,289 The males can be aggressive around meat, 107 00:17:19,790 --> 00:17:22,751 and the females need to tread carefully. 108 00:17:36,389 --> 00:17:37,891 Christine wants a share. 109 00:17:43,605 --> 00:17:45,816 And she's willing to take the risk. 110 00:18:05,460 --> 00:18:08,088 Wilson is watching carefully. 111 00:18:31,903 --> 00:18:33,822 Christine got what she came for. 112 00:18:40,370 --> 00:18:41,955 But she may not get to keep it. 113 00:18:58,555 --> 00:19:00,557 Wilson is taking out his frustrations. 114 00:19:26,875 --> 00:19:29,169 Fortunately, the baby wasn't hurt. 115 00:19:33,715 --> 00:19:37,510 But Christine needs to take her family away to safety. 116 00:20:14,339 --> 00:20:16,508 This is a quiet part of the forest, 117 00:20:17,384 --> 00:20:19,094 away from most of the group. 118 00:20:25,892 --> 00:20:27,811 But Christine is not alone. 119 00:21:19,237 --> 00:21:22,324 Gus can't offer protection from a chimp like Wilson. 120 00:21:23,450 --> 00:21:25,869 But at least he can offer some comfort... 121 00:21:30,957 --> 00:21:33,084 to Christine and her family. 122 00:22:13,875 --> 00:22:16,711 Abrams' challenge to Jackson has stalled. 123 00:22:20,632 --> 00:22:24,094 {\an8}Jackson is propped up by some powerful allies. 124 00:22:44,656 --> 00:22:47,033 And Abrams is lacking support. 125 00:22:53,164 --> 00:22:55,917 {\an8}But now there's another ambitious young chimp 126 00:22:56,918 --> 00:22:58,711 {\an8}with a grudge against Jackson. 127 00:23:24,821 --> 00:23:27,949 This could be the beginning of a powerful alliance. 128 00:23:48,303 --> 00:23:51,347 For now, Abrams and Wilson 129 00:23:51,973 --> 00:23:55,393 are joining a group of males to patrol westwards. 130 00:24:13,495 --> 00:24:15,038 Jackson is not with them. 131 00:24:22,712 --> 00:24:25,215 As powerful as he is in his own territory, 132 00:24:26,674 --> 00:24:29,010 Jackson fears the west. 133 00:24:36,434 --> 00:24:37,769 He grew up in the west 134 00:24:38,645 --> 00:24:41,231 and was allies with the westerners for many years. 135 00:24:45,235 --> 00:24:46,653 But when the group split, 136 00:24:47,529 --> 00:24:48,821 he deserted them 137 00:24:48,821 --> 00:24:52,408 to reign as alpha of the bigger central group. 138 00:24:57,872 --> 00:24:59,290 As conflict erupted, 139 00:25:00,083 --> 00:25:03,002 the western males targeted Jackson. 140 00:25:09,717 --> 00:25:10,969 He escaped with his life. 141 00:25:12,971 --> 00:25:14,931 But he still bears the scars. 142 00:25:21,688 --> 00:25:25,441 The westerners are a threat to all the central males. 143 00:25:26,317 --> 00:25:29,320 But they hold a bitter grudge against Jackson. 144 00:25:31,698 --> 00:25:33,992 And he fears them to this day. 145 00:25:47,130 --> 00:25:49,882 The borderlands are filled with Chrysophyllum. 146 00:26:00,935 --> 00:26:04,230 The westerners are spending more and more time here feeding. 147 00:26:10,570 --> 00:26:12,447 After killing Pork Pie, 148 00:26:12,447 --> 00:26:14,240 they've grown in confidence. 149 00:26:28,087 --> 00:26:31,341 And there are chimps in the group that won't stop there. 150 00:26:50,401 --> 00:26:54,030 Rollins and Damien will always want more territory. 151 00:27:10,838 --> 00:27:13,216 The western males are getting stronger. 152 00:27:26,145 --> 00:27:28,106 They are constantly displaying. 153 00:27:45,289 --> 00:27:47,625 The westerners are getting ready to make their move. 154 00:28:11,190 --> 00:28:13,985 And Richmond is at the center of it. 155 00:28:39,135 --> 00:28:40,678 He's not alpha anymore, 156 00:28:41,220 --> 00:28:43,347 but he's still a chimp to be feared. 157 00:29:00,615 --> 00:29:02,325 Bergl is back to full health. 158 00:29:11,250 --> 00:29:13,211 And that's not his only progress. 159 00:29:46,285 --> 00:29:48,329 He's regularly grooming with Garrison, 160 00:29:49,789 --> 00:29:51,624 who seems to be a good influence. 161 00:30:05,263 --> 00:30:08,349 And he's even started to bond with the west's patrol leaders. 162 00:30:28,870 --> 00:30:30,913 Wrestling is a good test of strength. 163 00:30:43,968 --> 00:30:47,597 And it gives Rollins and Damien a chance to see what Bergl is made of. 164 00:31:16,375 --> 00:31:18,920 The westerners need every chimp they've got. 165 00:31:24,759 --> 00:31:27,094 If they're going to claim this area for themselves, 166 00:31:27,094 --> 00:31:30,264 they'll have to confront the central chimps in their own territory... 167 00:31:31,849 --> 00:31:33,225 ...and push them back. 168 00:31:37,563 --> 00:31:39,899 For this, they need numbers. 169 00:31:43,569 --> 00:31:45,321 So they'll travel in force, 170 00:31:46,280 --> 00:31:48,824 males and females together. 171 00:32:51,220 --> 00:32:54,306 {\an8}Bartoli and Herzog are near the borderlands, 172 00:32:55,182 --> 00:32:59,228 {\an8}getting some peace away from Jackson and the other central males. 173 00:33:02,106 --> 00:33:03,149 It's much needed. 174 00:33:08,654 --> 00:33:10,781 But she has no idea what's coming. 175 00:33:33,763 --> 00:33:34,847 If they're caught, 176 00:33:35,347 --> 00:33:36,891 Herzog could be killed. 177 00:34:42,832 --> 00:34:45,751 A western male is chasing Bartoli into the canopy. 178 00:34:55,094 --> 00:34:56,929 She and Herzog have been separated. 179 00:35:14,071 --> 00:35:16,782 But Herzog won't leave his mother. 180 00:35:21,829 --> 00:35:23,289 He's going to try to protect her. 181 00:35:31,714 --> 00:35:33,424 He's got the attacker's attention. 182 00:35:40,472 --> 00:35:43,517 But now they're both trapped in the canopy... 183 00:35:48,022 --> 00:35:48,939 at the mercy 184 00:35:49,523 --> 00:35:50,983 of the western males. 185 00:36:26,101 --> 00:36:28,020 But the westerners aren't attacking. 186 00:36:40,032 --> 00:36:41,200 They're moving on. 187 00:37:13,857 --> 00:37:17,152 A lone family is not what the westerners are looking for. 188 00:37:47,891 --> 00:37:49,852 Bartoli and Herzog 189 00:37:50,477 --> 00:37:51,895 slip away together. 190 00:38:06,368 --> 00:38:09,496 The westerners are pushing deeper into the central territory. 191 00:38:20,174 --> 00:38:21,258 And some chimps 192 00:38:22,176 --> 00:38:23,552 are beginning to hesitate. 193 00:38:30,851 --> 00:38:33,312 For Carson, the risk is too great. 194 00:38:37,858 --> 00:38:40,444 And she's going to put E.O.'s safety first. 195 00:38:48,911 --> 00:38:51,914 Many females and younger chimps 196 00:38:52,706 --> 00:38:54,917 will drop out with the threat of real battle. 197 00:38:57,503 --> 00:38:58,420 And Joya 198 00:38:59,380 --> 00:39:01,382 is choosing to follow Carson home. 199 00:39:12,393 --> 00:39:15,729 A chimp like Bergl should fall back too. 200 00:39:17,147 --> 00:39:19,441 He's too young and too small. 201 00:39:29,868 --> 00:39:31,120 But Bergl is staying. 202 00:39:38,085 --> 00:39:39,628 He's grown in confidence. 203 00:39:42,297 --> 00:39:45,592 And for him, conflict is in the blood. 204 00:39:57,271 --> 00:39:59,022 Although neither of them know it... 205 00:40:05,737 --> 00:40:07,156 he is Rollins's son. 206 00:40:17,875 --> 00:40:21,712 The western males are deep inside the central territory. 207 00:40:31,054 --> 00:40:33,682 And they can sense their enemies are close. 208 00:41:11,512 --> 00:41:14,640 The central chimps have been caught off guard before. 209 00:41:27,444 --> 00:41:28,570 But not this time. 210 00:41:31,823 --> 00:41:33,867 {\an8}This time, they're ready. 211 00:42:19,621 --> 00:42:23,375 When two big groups come face-to-face, 212 00:42:24,126 --> 00:42:27,337 the outcome is always unpredictable. 213 00:42:58,035 --> 00:42:59,411 The westerners attack. 214 00:43:07,002 --> 00:43:09,921 And the centrallers meet them head-on. 215 00:43:28,440 --> 00:43:30,192 Bergl is right in the middle of it. 216 00:43:42,329 --> 00:43:44,706 The westerners are pushing the centrallers back. 217 00:44:23,286 --> 00:44:26,832 But some chimps still haven't joined the battle. 218 00:44:52,232 --> 00:44:54,609 If the centrallers are going to fight back, 219 00:44:54,609 --> 00:44:57,779 it will be now, behind their alpha. 220 00:45:16,673 --> 00:45:19,217 Jackson is face-to-face with his old rivals. 221 00:45:20,135 --> 00:45:22,888 The same chimps that tried to kill him years ago. 222 00:45:48,914 --> 00:45:50,415 Jackson shows no fear. 223 00:45:57,172 --> 00:45:59,090 And his group get behind him. 224 00:46:59,150 --> 00:47:01,653 The westerners have been pushed back. 225 00:47:02,821 --> 00:47:03,989 And they're retreating. 226 00:47:42,777 --> 00:47:45,238 The central chimps have held off their rivals. 227 00:47:49,451 --> 00:47:51,578 But Jackson has been injured in the battle. 228 00:48:10,597 --> 00:48:12,182 He defended his territory. 229 00:48:15,769 --> 00:48:16,978 But at what cost?