WEBVTT 00:00:08.120 --> 00:00:13.387 Narrator: Summer in Africa is a season of extremes. 00:00:13.517 --> 00:00:16.259 It separates the weak from the strong. 00:00:20.829 --> 00:00:24.006 For many, it's a time to feast. 00:00:27.531 --> 00:00:32.493 Offshore, fueled by sunlight, life flourishes. 00:00:34.538 --> 00:00:37.628 This is the season where giants visit 00:00:37.759 --> 00:00:41.371 and ocean wanderers emerge. 00:00:41.502 --> 00:00:44.722 But for others, summer will test their survival instincts 00:00:44.853 --> 00:00:50.206 and skills to the limit as they search for food and water. 00:00:53.035 --> 00:00:55.124 Summer brings new challenges 00:00:55.255 --> 00:00:57.648 and new opportunities for the creatures 00:00:57.779 --> 00:01:00.869 living through Africa's wild year. 00:01:46.131 --> 00:01:49.396 Nightfall along the South African coast 00:01:49.526 --> 00:01:51.136 brings a visitor. 00:01:56.272 --> 00:02:00.145 A loggerhead turtle drags herself onto the beach 00:02:00.276 --> 00:02:03.366 at the end of a 6,000-mile pilgrimage. 00:02:07.675 --> 00:02:10.982 She's guided by an internal compass, 00:02:11.113 --> 00:02:12.810 using the Earth's magnetic field 00:02:12.941 --> 00:02:16.031 to return to the place where she was born. 00:02:19.164 --> 00:02:22.777 Ready to lay eggs of her own, 00:02:22.907 --> 00:02:24.431 she starts to dig, 00:02:24.561 --> 00:02:27.956 using her huge flippers to excavate a hole. 00:02:35.311 --> 00:02:37.400 Her timing is key. 00:02:41.970 --> 00:02:46.627 It's December, the start of the Southern Hemisphere summer. 00:02:49.107 --> 00:02:50.761 Over the next two months, 00:02:50.892 --> 00:02:53.460 the warm temperatures will play a vital role 00:02:53.590 --> 00:02:55.418 in her hatchlings' future. 00:03:04.209 --> 00:03:08.605 Finally, she stretches her hind flippers into the sand 00:03:08.736 --> 00:03:10.433 to make a deep well. 00:03:18.963 --> 00:03:21.357 Her nest is ready. 00:03:23.272 --> 00:03:28.364 Over the next 3 hours, she lays around 100 eggs. 00:03:30.410 --> 00:03:34.065 This nesting spot is no ordinary beach. 00:03:34.196 --> 00:03:38.853 The sand here is rich in titanium ore. 00:03:38.983 --> 00:03:41.377 The titanium stores the sun's heat, 00:03:41.508 --> 00:03:46.338 creating the perfect incubator for her eggs. 00:03:46.469 --> 00:03:48.428 The * of her hatchlings will be determined 00:03:48.558 --> 00:03:50.908 by how much heat they get from the sun, 00:03:51.039 --> 00:03:55.826 which varies depending how deep she buried her eggs. 00:03:55.957 --> 00:03:58.263 Eggs that are incubated in cool conditions, 00:03:58.394 --> 00:04:01.571 at the bottom of the nest, will become males. 00:04:03.443 --> 00:04:05.836 Those that develop closer to the surface, 00:04:05.967 --> 00:04:10.406 at higher temperatures, will become females. 00:04:10.537 --> 00:04:13.409 But she has to strike a delicate balance. 00:04:13.540 --> 00:04:15.933 If the temperature of the nest rises too high, 00:04:16.064 --> 00:04:20.503 her babies will grow smaller and weaker than normal, 00:04:20.634 --> 00:04:23.463 giving them a lower chance of survival. 00:04:25.856 --> 00:04:28.468 She's arrived early enough in the season 00:04:28.598 --> 00:04:30.382 to give her eggs time to develop 00:04:30.513 --> 00:04:33.473 before the worst of the summer heat kicks in. 00:04:37.651 --> 00:04:40.915 Finally, she summons every last ounce of energy 00:04:41.045 --> 00:04:43.178 to cover the nest. 00:04:45.789 --> 00:04:48.313 There's nothing more she can do. 00:04:48.444 --> 00:04:51.882 Her role is complete. 00:04:52.013 --> 00:04:56.321 The fate of her hatchlings rests in the summer sun. 00:05:02.240 --> 00:05:06.506 Exhausted, the female loggerhead heads for the ocean, 00:05:06.636 --> 00:05:08.595 where she'll spend the next four years 00:05:08.725 --> 00:05:12.076 before returning to shore to breed again. 00:05:26.917 --> 00:05:29.964 Temperature and day length drive the seasons 00:05:30.094 --> 00:05:33.445 of the natural world. 00:05:33.576 --> 00:05:36.971 Summer is the season when the Earth's axis 00:05:37.101 --> 00:05:40.452 is tilted most towards the sun, 00:05:40.583 --> 00:05:44.369 bringing light and heat to one hemisphere 00:05:44.500 --> 00:05:48.809 while cold and darkness falls across the other. 00:05:48.939 --> 00:05:51.942 These seasonal shifts create dramatic changes 00:05:52.073 --> 00:05:55.380 in feeding patterns. 00:05:55.511 --> 00:06:00.168 For some, it marks the start of a summer bonanza. 00:06:09.612 --> 00:06:12.615 December, and off the coast of Tanzania, 00:06:12.746 --> 00:06:16.184 temperatures in the Indian Ocean are heating up. 00:06:23.844 --> 00:06:26.847 These warm waters are home to some of the richest 00:06:26.977 --> 00:06:28.631 coral reefs in the world. 00:06:40.208 --> 00:06:44.429 An offshore tapestry of tropical islands and channels. 00:06:51.480 --> 00:06:56.006 From the depths, a mysterious giant emerges from hiding. 00:07:12.719 --> 00:07:16.418 The world's largest oceanic fish. 00:07:19.116 --> 00:07:20.683 A whale shark. 00:07:24.948 --> 00:07:27.385 This is one of the few places on Earth 00:07:27.516 --> 00:07:30.040 where whale sharks surface to feed. 00:07:35.089 --> 00:07:38.788 A 30-foot-long giant is joined by a smaller juvenile 00:07:38.919 --> 00:07:43.445 whale shark as he searches for his microscopic prey. 00:07:46.840 --> 00:07:48.232 Plankton. 00:07:48.493 --> 00:07:51.932 Some of these creatures measure less than half an inch long. 00:08:00.897 --> 00:08:03.987 Summer causes an explosion in tiny plants 00:08:04.118 --> 00:08:06.381 that flourish in sunlight. 00:08:11.299 --> 00:08:14.215 These, in turn, provide food for zooplankton, 00:08:14.345 --> 00:08:18.741 clouds of tiny animals that are at the mercy of ocean currents. 00:08:23.441 --> 00:08:26.270 And the whale sharks that eat them. 00:08:32.755 --> 00:08:35.366 The animals swim slowly at the surface, 00:08:35.497 --> 00:08:37.978 propelled by their huge tails. 00:08:40.720 --> 00:08:43.200 Every individual can be identified 00:08:43.331 --> 00:08:45.507 by a unique spot pattern. 00:08:49.598 --> 00:08:56.126 The adult opens his gaping 5-foot mouth to engulf seawater, 00:08:56.257 --> 00:08:58.346 flushing it out through his gills, 00:08:58.476 --> 00:09:01.175 which act like a sieve, 00:09:01.305 --> 00:09:03.786 trapping thousands of plankton inside. 00:09:09.836 --> 00:09:13.187 Whale sharks are known to travel up to 6,000 miles a year 00:09:13.317 --> 00:09:14.797 in search of food. 00:09:42.129 --> 00:09:43.695 But in Tanzania, 00:09:43.826 --> 00:09:47.177 many whale sharks are resident offshore year-round. 00:09:52.748 --> 00:09:56.056 Only coming to the surface to feed in shallow water 00:09:56.186 --> 00:09:57.840 over the summer... 00:10:03.977 --> 00:10:07.632 ...drawn out of hiding by the seasonal bounty. 00:10:21.255 --> 00:10:24.693 As the mercury rises across southern Africa... 00:10:26.434 --> 00:10:28.436 ...inland, the abundance of spring 00:10:28.566 --> 00:10:32.614 has given way to the relentless heat of summer. 00:10:34.659 --> 00:10:37.532 It pushes animals to their limits... 00:10:39.447 --> 00:10:42.450 ...and tests their newfound independence. 00:10:47.977 --> 00:10:51.633 The vast Kgalagadi Transfrontier Park. 00:10:54.679 --> 00:10:59.554 Its name means "the thirst land," 00:10:59.684 --> 00:11:04.951 an arid expanse that stretches some 14,500 square miles 00:11:05.081 --> 00:11:08.911 across South Africa, Namibia, and Botswana. 00:11:18.268 --> 00:11:20.705 For a coalition of four cheetah brothers, 00:11:20.836 --> 00:11:24.927 this vast, hostile wilderness is home. 00:11:27.408 --> 00:11:30.063 This is their first full summer alone 00:11:30.193 --> 00:11:32.674 without the support of their mother. 00:11:34.110 --> 00:11:36.721 It's been several days since they've eaten 00:11:36.852 --> 00:11:40.638 and they need to make a kill soon. 00:11:40.769 --> 00:11:45.034 Midday temperatures here soar over 100 degrees. 00:11:47.471 --> 00:11:48.733 In the heat of the day, 00:11:48.864 --> 00:11:51.736 the predators spot an opportunity, 00:11:51.867 --> 00:11:53.956 a herd of wildebeest. 00:11:58.961 --> 00:12:02.051 Hunting in this heat is a risky strategy. 00:12:05.098 --> 00:12:08.971 They'll have to strike fast or risk exhaustion. 00:12:17.284 --> 00:12:20.156 The coalition of cheetahs spread out. 00:12:23.464 --> 00:12:29.165 On the lookout for the weakest animal in the herd. 00:12:32.516 --> 00:12:34.127 The hunt is on. 00:12:41.743 --> 00:12:43.223 The wildebeest sound the alarm. 00:12:46.574 --> 00:12:48.489 They turn tail in unison. 00:12:48.619 --> 00:12:50.447 There's safety in numbers. 00:12:55.583 --> 00:12:56.845 The cheetah's luck is in. 00:12:56.976 --> 00:12:59.587 A young animal with an injured leg. 00:13:07.987 --> 00:13:10.032 They close ranks around their prey. 00:13:15.516 --> 00:13:20.216 Working together should give them an advantage. 00:13:20.347 --> 00:13:22.044 To hunt successfully, they must stick 00:13:22.175 --> 00:13:25.395 to the tail of the prey to bring it down. 00:13:31.358 --> 00:13:33.403 But the young calf turns to face them. 00:13:43.457 --> 00:13:46.634 His horns are powerful enough to cause serious injury. 00:13:54.555 --> 00:13:56.600 If he keeps up his defense long enough, 00:13:56.731 --> 00:13:59.081 he may be in with a chance. 00:14:02.519 --> 00:14:05.566 The brothers lack the experience to coordinate their attack 00:14:05.696 --> 00:14:07.263 and bring down the animal. 00:14:20.102 --> 00:14:22.887 Only around half of cheetah hunts end in a kill. 00:14:31.244 --> 00:14:33.463 It's a stalemate. 00:14:33.594 --> 00:14:36.640 The wildebeest is exhausted. 00:14:36.771 --> 00:14:38.903 But so too are the cheetahs. 00:14:46.128 --> 00:14:49.305 They are still unable to make a kill without their mother. 00:15:07.889 --> 00:15:09.891 The heat proves too much. 00:15:10.021 --> 00:15:12.285 The brothers retreat to the shade. 00:15:20.336 --> 00:15:23.687 And the wildebeest makes a break for it. 00:15:25.733 --> 00:15:27.865 The cheetahs need to conserve their energy 00:15:27.996 --> 00:15:30.346 for the next opportunity... 00:15:33.262 --> 00:15:35.395 ...and further hone their skills 00:15:35.525 --> 00:15:37.962 if they are to survive the summer. 00:15:49.757 --> 00:15:53.935 Not all parts of Africa are a desert in the summer. 00:16:05.599 --> 00:16:11.605 The Okavango Delta is a diverse wilderness of wetlands, 00:16:11.735 --> 00:16:17.567 plains, forests, and lagoons. 00:16:17.698 --> 00:16:21.571 And it supports animals in their thousands... 00:17:00.654 --> 00:17:04.440 ...fed by floodwaters that arrived many months earlier. 00:17:24.634 --> 00:17:25.896 For a herd of zebra, 00:17:26.070 --> 00:17:29.030 these floodplains provide rich grazing grounds. 00:17:50.094 --> 00:17:53.097 Over 20,000 of them will pass through the Okavango 00:17:53.228 --> 00:17:55.143 during this time of year. 00:17:58.712 --> 00:18:01.758 But this herd are unaware that they are being watched 00:18:01.889 --> 00:18:04.065 as they cross a waterway. 00:18:09.853 --> 00:18:12.769 A lioness spots an opportunity. 00:18:17.600 --> 00:18:21.082 Her pride has 10 hungry mouths to feed. 00:18:28.872 --> 00:18:31.527 She's flanked by another pride member. 00:18:31.658 --> 00:18:35.923 They approach downwind, giving them an advantage. 00:18:42.712 --> 00:18:46.499 They stalk the herd, looking for a weak link. 00:18:52.331 --> 00:18:53.897 A zebra sounds the alarm. 00:18:56.204 --> 00:18:59.120 Too late. The ambush is on. 00:19:08.738 --> 00:19:11.741 But the lioness can't bring down an animal this size 00:19:11.872 --> 00:19:13.526 without help. 00:19:21.316 --> 00:19:23.536 The second lioness arrives. 00:19:33.720 --> 00:19:35.591 And it's over. 00:19:51.868 --> 00:19:55.437 A kill this size will sustain her pride for several days 00:19:55.568 --> 00:19:57.744 before they need to hunt again. 00:20:01.269 --> 00:20:06.448 But this time of plenty won't last forever. 00:20:06.579 --> 00:20:08.102 Over the next few months, 00:20:08.232 --> 00:20:11.627 the waters that fuel life on the delta will recede, 00:20:11.758 --> 00:20:14.108 and the summer herds will leave. 00:20:21.985 --> 00:20:26.381 The lions will be forced to work harder to feed their family. 00:20:45.618 --> 00:20:48.098 The influence of summer is felt far and wide 00:20:48.229 --> 00:20:50.057 across southern Africa. 00:20:57.368 --> 00:21:00.110 Inland, thunderstorms gather. 00:21:05.899 --> 00:21:09.555 They combine with the movements of cyclones offshore 00:21:09.685 --> 00:21:12.253 to create gale-force winds. 00:21:17.650 --> 00:21:21.610 Out at sea, it's a catalyst for change. 00:21:26.746 --> 00:21:29.923 Summer winds gust along the west coast of Africa, 00:21:30.053 --> 00:21:33.274 blowing the surface water out to the ocean. 00:21:35.885 --> 00:21:39.889 And cold, nutrient-rich water rises from the depths 00:21:40.020 --> 00:21:41.978 to replace it. 00:21:43.719 --> 00:21:47.462 The upward flow contains vast quantities of krill 00:21:47.593 --> 00:21:49.856 pushed towards the surface. 00:21:53.686 --> 00:21:57.254 The event attracts one of Africa's largest visitors 00:21:57.385 --> 00:21:59.866 to feast on a summer bounty. 00:22:16.535 --> 00:22:20.364 A 33-ton giant. 00:22:30.157 --> 00:22:36.119 These seven humpback whales have swum 3,500 miles from Antarctica 00:22:36.250 --> 00:22:39.209 to be here to feed on krill. 00:22:43.387 --> 00:22:48.175 They gather together in super groups of 20 or more animals. 00:23:05.453 --> 00:23:08.369 This is what they are after. 00:23:11.546 --> 00:23:15.202 Female lunges as she swims towards the surface. 00:23:28.911 --> 00:23:31.000 Inside her mouth, a system of bristles, 00:23:31.131 --> 00:23:34.830 called baleen, filter the krill from the water. 00:23:39.139 --> 00:23:41.707 This summer feeding frenzy helps her 00:23:41.837 --> 00:23:44.623 to build vital fat stores called blubber. 00:23:48.539 --> 00:23:50.237 Pushed to the brink of extinction 00:23:50.367 --> 00:23:52.935 by whaling in the early 20th century, 00:23:53.066 --> 00:23:55.851 humpback whales have made a staggering comeback 00:23:55.982 --> 00:23:58.027 in these waters. 00:24:08.081 --> 00:24:13.086 Now over 20,000 migrate along the southern African coastline 00:24:13.216 --> 00:24:18.091 to feed and breed every year. 00:24:18.221 --> 00:24:20.310 Once the summer glut is over, 00:24:20.441 --> 00:24:22.748 the female humpback will travel north, 00:24:22.878 --> 00:24:25.925 towards the warmer waters of the equator, 00:24:26.055 --> 00:24:27.883 where she'll give birth. 00:24:38.111 --> 00:24:42.550 She'll eat very little, relying on her blubber to survive, 00:24:42.681 --> 00:24:46.859 until she and her calf return to Antarctic waters. 00:25:03.136 --> 00:25:06.487 The southern drylands of Namibia. 00:25:09.098 --> 00:25:13.494 Summer here is the ultimate test for desert species. 00:25:16.540 --> 00:25:21.502 Stretching inland over 345,000 square miles. 00:25:23.896 --> 00:25:27.464 This is a vast expanse of deserts, 00:25:27.595 --> 00:25:32.513 salt pans, dry riverbeds, and rocky mountains. 00:25:35.821 --> 00:25:40.521 In January, temperatures creep over 120 degrees. 00:25:56.189 --> 00:26:00.933 In a land scorched by extreme heat and unrelenting winds, 00:26:01.063 --> 00:26:04.327 plants and animals here have evolved to last months 00:26:04.458 --> 00:26:06.808 without water. 00:26:13.336 --> 00:26:16.818 To live here, it takes a specialist. 00:26:22.606 --> 00:26:27.786 This century-old quiver tree is shaped by its barren home. 00:26:31.528 --> 00:26:33.966 Inside the tree's stem and branches, 00:26:34.096 --> 00:26:37.404 a spongy fiber stores large quantities of water 00:26:37.534 --> 00:26:40.799 over long periods of time, allowing the quiver tree 00:26:40.929 --> 00:26:44.019 to soak up the hot desert's sporadic rains. 00:26:48.850 --> 00:26:52.680 Its succulent leaves cannot escape the relentless sun. 00:26:52.811 --> 00:26:55.988 Instead, they've adapted to resist it. 00:27:01.558 --> 00:27:03.125 Their smooth and waxy surface 00:27:03.256 --> 00:27:06.650 prevents moisture from evaporating. 00:27:11.351 --> 00:27:15.877 And its branches are coated with a heat-reflective white powder. 00:27:23.450 --> 00:27:27.236 An evolutionary success, it towers at 30 feet 00:27:27.367 --> 00:27:30.631 above the surrounding low-level desert scrub. 00:27:40.380 --> 00:27:43.687 But not all species can adapt. 00:27:56.613 --> 00:27:59.703 This ghost forest tells a different story. 00:28:08.016 --> 00:28:11.498 600 years ago, climate patterns shifted, 00:28:11.628 --> 00:28:14.675 and summers grew longer and hotter. 00:28:23.423 --> 00:28:26.600 In the prolonged drought, desert sands encroached 00:28:26.730 --> 00:28:30.560 and blocked the path of the long lost Tsauchab River, 00:28:30.691 --> 00:28:33.520 killing the ancient camelthorn trees. 00:28:38.438 --> 00:28:41.093 All that remains are their blackened skeletons, 00:28:41.223 --> 00:28:46.750 scorched by the summer sun, too dry to decompose 00:28:46.881 --> 00:28:49.492 and inedible to any passing animal. 00:28:54.889 --> 00:28:59.502 Six centuries old, they stand suspended in time. 00:29:06.379 --> 00:29:10.557 A stark reminder of the power the Earth's climate has 00:29:10.687 --> 00:29:12.776 over its inhabitants. 00:29:22.569 --> 00:29:26.790 A Peringuey's adder navigates the surrounding dunes. 00:29:42.154 --> 00:29:43.982 His sidewinding motion 00:29:44.112 --> 00:29:47.463 helps him glide over the slippery sand, 00:29:47.594 --> 00:29:49.813 however steep a slope. 00:30:04.567 --> 00:30:06.265 With the day coming to an end, 00:30:06.395 --> 00:30:09.181 he's looking for a place to set up an ambush. 00:30:16.623 --> 00:30:21.628 He hasn't eaten for two months and is long overdue a meal. 00:30:26.459 --> 00:30:30.854 But during summer in the desert, there's a limited menu. 00:30:38.427 --> 00:30:41.082 Time to disappear in the cool sand 00:30:41.213 --> 00:30:43.867 and wait for the cover of darkness. 00:30:47.958 --> 00:30:49.308 It doesn't hurt to escape 00:30:49.438 --> 00:30:52.224 the sun's relentless summer rays, either. 00:31:26.084 --> 00:31:30.653 This web-footed gecko is exactly what the adder is after. 00:31:34.614 --> 00:31:39.314 Its strategy for summer survival is to avoid the sun altogether. 00:31:42.056 --> 00:31:45.146 After spending the day buried in his burrow, 00:31:45.277 --> 00:31:47.322 he only emerges at night. 00:31:51.500 --> 00:31:54.721 The geckos eyes are huge, to help spot prey 00:31:54.851 --> 00:31:59.073 and avoid predators in the darkness. 00:31:59.204 --> 00:32:02.337 So it's vital he keeps them clean. 00:32:10.084 --> 00:32:14.523 All he needs to do to survive is tread carefully 00:32:14.654 --> 00:32:17.178 and avoid the adder's path. 00:32:25.882 --> 00:32:28.755 He's out of striking distance. 00:32:28.885 --> 00:32:30.496 Just. 00:32:35.370 --> 00:32:39.331 For the adder, the waiting game continues. 00:32:47.817 --> 00:32:51.212 It's now mid-summer in the southern drylands. 00:32:51.343 --> 00:32:52.692 In the relentless heat, 00:32:52.822 --> 00:32:56.391 animals turn to desperate measures to find food. 00:32:59.177 --> 00:33:00.874 On a rocky outcrop, 00:33:01.004 --> 00:33:04.965 a family of armadillo lizars soak up the sun's heat. 00:33:08.490 --> 00:33:10.797 These heavily armored reptiles live 00:33:10.927 --> 00:33:13.756 in social groups of up to 60. 00:33:16.150 --> 00:33:18.718 Among them, a protective male. 00:33:18.848 --> 00:33:22.678 He'll do whatever it takes to try and defend his harem, 00:33:22.809 --> 00:33:27.422 however threatening or large an intruder may be. 00:33:27.553 --> 00:33:31.296 The group never strays too far from their fortress. 00:33:31.426 --> 00:33:33.080 And for good reason. 00:33:35.778 --> 00:33:37.476 They may be tough, 00:33:37.606 --> 00:33:41.654 but a determined hunter could still catch them unawares. 00:33:45.962 --> 00:33:48.574 A polecat is on the prowl. 00:33:50.358 --> 00:33:54.841 Normally, he hunts under cover of night, 00:33:54.971 --> 00:33:56.582 but in the dry summer season, 00:33:56.712 --> 00:34:00.455 he's forced to try his luck during the heat of the day. 00:34:02.936 --> 00:34:04.894 The lizards freeze. 00:34:07.462 --> 00:34:09.595 Perhaps he won't notice. 00:34:12.859 --> 00:34:17.124 But a passing beetle is just too tempting. 00:34:19.257 --> 00:34:21.128 It blows their cover. 00:34:23.478 --> 00:34:27.482 But these lizards are masters of self-defense. 00:34:27.613 --> 00:34:30.268 The male curls up into a tight defensive ball, 00:34:30.398 --> 00:34:32.748 holding his tail in his mouth, 00:34:34.533 --> 00:34:38.841 a move that protects his vulnerable, softer stomach. 00:34:38.972 --> 00:34:40.408 All the polecat is rewarded 00:34:40.539 --> 00:34:44.325 with is an unsatisfying mouthful of sharp scales. 00:34:48.721 --> 00:34:52.115 He can't work out how to crack the lizard's defenses. 00:35:10.873 --> 00:35:13.920 Finally, he uncurls the reptile, 00:35:14.050 --> 00:35:16.531 but the lizard flattens himself to the ground 00:35:16.662 --> 00:35:19.795 to keep his soft underbelly protected. 00:35:19.926 --> 00:35:24.539 Then the lizard spots a window and makes a break for it. 00:35:27.412 --> 00:35:29.196 He'll live another day. 00:35:31.154 --> 00:35:33.418 The polecat will have to continue his search 00:35:33.548 --> 00:35:35.681 for food elsewhere. 00:35:49.738 --> 00:35:53.176 But another creature is about to have better luck 00:35:53.307 --> 00:35:55.135 under the summer sun. 00:36:08.148 --> 00:36:10.890 A Namaqua chameleon is warming himself 00:36:11.020 --> 00:36:12.761 in the heat of the morning. 00:36:22.336 --> 00:36:26.514 He's a master of disguise, able to change color, 00:36:26.645 --> 00:36:30.213 to communicate and blend into his surroundings. 00:36:32.172 --> 00:36:34.566 It's the secret to his success. 00:36:41.834 --> 00:36:43.575 If he can get going. 00:36:50.799 --> 00:36:54.586 The cold-blooded reptile grows darker to absorb heat. 00:37:04.030 --> 00:37:08.687 But as the day warms up, he changes to a lighter hue... 00:37:10.384 --> 00:37:12.995 reflecting the sun's rays... 00:37:17.086 --> 00:37:21.787 turning the strong summer sun from his enemy into his ally. 00:37:41.328 --> 00:37:43.722 The ground may be too hot to touch, 00:37:43.852 --> 00:37:47.073 but he's on the prowl for his next meal. 00:38:03.089 --> 00:38:05.091 His eyes move independently, 00:38:05.221 --> 00:38:07.876 able to focus on separate targets. 00:38:22.456 --> 00:38:24.719 It's game over for this beetle. 00:38:28.549 --> 00:38:33.119 He's a voracious feeder and will hunt down around 12 meals a day, 00:38:33.249 --> 00:38:35.817 helping to provide him with the moisture he needs 00:38:35.948 --> 00:38:39.342 to survive the harsh summer months. 00:38:45.523 --> 00:38:47.960 Life in Africa's southern drylands 00:38:48.090 --> 00:38:51.964 has evolved to survive without water. 00:38:52.094 --> 00:38:58.144 But further south, animals depend on seasonal rains. 00:38:58.274 --> 00:39:02.540 It's January, and large areas of southern Africa 00:39:02.670 --> 00:39:04.716 are experiencing drought. 00:39:15.727 --> 00:39:18.164 While some face hardship, 00:39:18.294 --> 00:39:22.037 others sense opportunity. 00:39:22.168 --> 00:39:27.608 A free meal for scavengers, large and small. 00:39:33.962 --> 00:39:37.226 This spotted hyena clan are relying on their strong 00:39:37.357 --> 00:39:40.360 social bonds to endure the dry season. 00:39:49.412 --> 00:39:51.850 The biggest female is in charge. 00:39:51.980 --> 00:39:54.809 All bow to the matriarch. 00:39:56.463 --> 00:39:59.814 She's picked up the scent of a potential meal. 00:40:04.210 --> 00:40:08.388 Summer has claimed its first victim, 00:40:08.518 --> 00:40:11.217 a rhino taken by the drought. 00:40:18.180 --> 00:40:20.487 Hyena hunt the majority of their food, 00:40:20.618 --> 00:40:23.838 but scavenging means easy pickings. 00:40:36.764 --> 00:40:38.287 The matriarch approaches, 00:40:38.418 --> 00:40:40.681 followed by the rest of her clan. 00:40:44.859 --> 00:40:47.296 But to earn a place at this dining table, 00:40:47.427 --> 00:40:52.737 you need to show some respect and wait your turn. 00:40:52.867 --> 00:40:54.695 The matriarch and the rest of the females 00:40:54.826 --> 00:40:56.697 surround the carcass. 00:41:00.222 --> 00:41:03.922 Close by. a juvenile male waits it out. 00:41:04.052 --> 00:41:07.360 He needs to be patient. 00:41:07.490 --> 00:41:09.884 As the lowest-ranked member of the clan, 00:41:10.015 --> 00:41:12.452 he respects the pecking order. 00:41:14.497 --> 00:41:17.370 The matriarch uses her bone-crushing teeth, 00:41:17.500 --> 00:41:21.504 her carnassials, to grind through the rhino's thick hide 00:41:21.635 --> 00:41:24.682 to reach the soft flesh inside. 00:41:24.812 --> 00:41:26.553 Her powerful digestive system 00:41:26.684 --> 00:41:29.382 is equipped with highly acidic fluids. 00:41:29.512 --> 00:41:32.515 It means she can digest every part of her prey, 00:41:32.646 --> 00:41:39.131 including skin, teeth, horns, hooves, and bones. 00:41:39.261 --> 00:41:41.742 She can even digest any toxic bacteria 00:41:41.873 --> 00:41:44.658 that has started growing in the summer heat. 00:41:48.967 --> 00:41:53.406 The juvenile male sneaks in for scraps where he can. 00:42:01.022 --> 00:42:04.591 Finally full, the matriarch heads off. 00:42:11.163 --> 00:42:16.168 The youngster can drop his guard, and he dives in. 00:42:16.298 --> 00:42:18.039 He may be last to take his seat, 00:42:18.170 --> 00:42:21.956 but there's plenty left of the 2-ton rhino. 00:42:22.087 --> 00:42:26.569 No more polite waiting on the sidelines. 00:42:26.700 --> 00:42:29.572 The time to mind his manners is over. 00:42:35.578 --> 00:42:38.190 But just as he settles in to feast, 00:42:38.320 --> 00:42:40.583 the cleanup crew turn up. 00:42:48.287 --> 00:42:51.377 Vultures, and their numbers are growing. 00:42:54.684 --> 00:42:56.425 He's going to have to hold his own 00:42:56.556 --> 00:42:58.645 to keep a place at the table. 00:43:01.387 --> 00:43:04.564 Being on the bottom rung of the pecking order is hard work 00:43:04.694 --> 00:43:06.174 when you are alone. 00:43:12.746 --> 00:43:14.052 Finally, the young hyena 00:43:14.182 --> 00:43:16.968 gives up against the sheer number of birds. 00:43:25.237 --> 00:43:27.935 But the temptation proves too much. 00:43:28.066 --> 00:43:32.853 In a last valiant attempt, he charges back in. 00:43:47.999 --> 00:43:52.003 But try as he might, he's hopelessly outnumbered. 00:44:01.882 --> 00:44:06.060 The vultures claim their prize and steal his meal 00:44:06.191 --> 00:44:08.062 from under his eyes. 00:44:27.908 --> 00:44:32.173 It's time to give up and find his family. 00:44:32.304 --> 00:44:34.784 These scavengers perform an essential service. 00:44:34.915 --> 00:44:40.138 By stripping a carcass bear, they prevent diseases spreading. 00:44:40.268 --> 00:44:43.184 These easy summer pickings will keep the hyena clan 00:44:43.315 --> 00:44:46.100 and the vultures going for several more days. 00:44:46.231 --> 00:44:48.755 Until only the skeleton remains. 00:45:01.159 --> 00:45:06.468 On the South African coast, life stirs beneath the sand. 00:45:10.951 --> 00:45:15.042 A whole summer has passed since the female loggerhead turtle 00:45:15.173 --> 00:45:19.133 hauled herself onto this remote beach to lay her eggs. 00:45:37.456 --> 00:45:41.590 The beach has provided the perfect incubator. 00:45:41.721 --> 00:45:44.028 And thanks to the mother's early arrival, 00:45:44.158 --> 00:45:48.336 the hatchlings emerge strong and healthy. 00:46:07.747 --> 00:46:10.358 But their challenges begin immediately. 00:46:19.237 --> 00:46:23.806 Under the light of a full moon, it's a race for the water. 00:46:31.249 --> 00:46:36.210 At around 2 inches long, they are extremely vulnerable. 00:46:40.258 --> 00:46:43.826 The last to hatch has some catching up to do. 00:46:45.611 --> 00:46:48.831 On his own, he's exposed. 00:46:52.618 --> 00:46:56.230 And easy pickings for a passing predator. 00:46:58.537 --> 00:47:02.715 Ghost crabs scavenge and hunt by night. 00:47:04.543 --> 00:47:07.198 And tonight, his job is easy. 00:47:13.247 --> 00:47:15.945 Without the safety of numbers, the hatchling stands 00:47:16.076 --> 00:47:18.426 little chance against the strong pincers. 00:47:24.432 --> 00:47:25.781 Just minutes old 00:47:25.912 --> 00:47:30.438 and already the nest has lost a precious newcomer. 00:47:37.924 --> 00:47:40.187 Many more will drown in the surf, 00:47:40.318 --> 00:47:43.495 and of the 100 or so eggs laid two months ago, 00:47:43.625 --> 00:47:47.455 less than 10 will survive to adulthood. 00:47:52.025 --> 00:47:53.331 But those that make it 00:47:53.461 --> 00:47:56.682 will go on to explore the world's oceans. 00:48:01.339 --> 00:48:04.690 Migrating thousands of miles around the globe. 00:48:31.717 --> 00:48:35.068 30 summers will pass before the females will return 00:48:35.199 --> 00:48:38.506 to this very beach to come ashore once more... 00:48:42.554 --> 00:48:46.166 ...allowing the cycle of life to continue. 00:49:09.711 --> 00:49:13.106 Summer pushes animals to the extreme, 00:49:13.237 --> 00:49:15.978 as the elements dictate the rhythm of life. 00:49:19.634 --> 00:49:23.986 The weak have been exposed, and the strong have thrived. 00:49:26.902 --> 00:49:32.865 As the season draws to a close, change is in the air. 00:49:32.995 --> 00:49:37.565 Falling temperatures trigger many to leave as autumn arrives. 00:49:41.569 --> 00:49:44.398 The new season will bring relief to many... 00:49:47.271 --> 00:49:49.795 ...offering a short respite 00:49:49.925 --> 00:49:54.060 and chance to prepare before winter descends. 00:49:54.191 --> 00:49:58.412 And the challenges of Africa's wild year continue.