How Do Animals Smell Rain 100 Miles Away?

Added: 2026-05-22

[00:00:14]Botswana is a dry country.

[00:00:17]It is dominated by the Kalahari. Flat, dusty, endless.

[00:00:25]For most of the year, its surface is without water.

[00:00:30]So water is priceless.

[00:00:35]>> It forces [music] domesticated and wild animals to compete.

[00:00:49]The Baron Bateti River forms the western boundary of the Makadiki basin, a vast sea of arid grasslands and salt pans.

[00:01:01]Makadikadi is a land of extremes. When the rains come, the salt pans fill [music] with water and prairieike grasslands are renewed.

[00:01:17]Southern Africa's greatest freeranging herds of wilderbeast and zebra spread out across the basin, and memories of the drought evaporate on the cool breeze.

[00:01:33][music] The Okavango River [music] rises in the highlands of Angola and eventually flows into northwest Botswana.

[00:01:45]It is the last of the great rivers still to flow into the ancient lake basin of Makarikari.

[00:01:58]The giant river transforms the Kalahari into fertile swamplands but never reaches the sea.

[00:02:05]Most of the water [music] evaporates or is swallowed by the sand.

[00:02:12]The river breaks into many channels that fan out to form [music] an inland delta.

[00:02:17]Only one channel escapes the delta and flows into the Kalahari beyond the Betetti Channel.

[00:02:25]Most years a tiny percentage [music] of flood water makes it to the channel.

[00:02:29]Sometimes nothing at all. This region of Batswana [music] is the bed of one of Africa's greatest ancient lakes, Makadikadi.

[00:02:38]The Boteti Channel connects the Okavango Delta to the vast Makadikadi [music] soda pans where the ancient lake finally disappeared.

[00:02:47]Today, the only regular water supply into this region comes from the Okavango.

[00:02:54]The water hasn't reached beyond the delta in the last 7 [music] years, and the last pools in the channel are slowly drying up.

[00:03:05]This herd of hippopotamus watches their pool shrink year on year, waiting for the floods to come.

[00:03:12]Now they rely on the government tanker to keep their wallow wet.

[00:03:27]But it's not just hippos that need water. Small villages surrounding the channel also rely on its supply.

[00:03:35]Thorn bush fences help protect the vill's wells from wandering wildlife.

[00:03:43]Dark spots on the hippo's skin reveal escaping sweat.

[00:03:47]Hippos lose a great deal of water through their skin and must stay cool in the heat of the day.

[00:03:54]If the hole dries up, they'll have to move on or die.

[00:04:04]From the air, a mosaic of wells shows the impact of the villagers and their animals on the dusty bed [music] of the channel.

[00:04:19]The maribou stalk feeds on carrion. For this bird, drought is a time of plenty.

[00:04:33]All life in the channel is in search of water.

[00:04:37]Wild and domesticated animals are forced into uneasy and unnatural association.

[00:04:56]Stalks scavenge the dried up pools, feeding on the remains of stranded catfish.

[00:05:11]There's plenty of carrying to be found in these desperate times.

[00:05:17]Villagers can access water beneath the channel from their wells, but their protective thorn bush fences are not always effective.

[00:05:35]During the night, two young hippos fell into a well, drawn by the prospect of fresh water.

[00:05:42]So has a cow.

[00:05:49]The cow was pregnant and gave birth on top of the hippos. The farmer and officials are desperate to at least save the calf.

[00:05:59][music] Cattle are a symbol of wealth and farmers can't [music] afford to lose them to the wells.

[00:06:34]The hippos must be under great stress, but fortunately for everyone, they remain calm.

[00:06:45]Wildlife officials [music] are keen to see that the hippos are safely released and the farmer needs to get them out of the well before he can release his cow.

[00:07:11]The pressure on these wild animals must be intolerable.

[00:07:20]But survival takes precedence over everything else.

[00:07:27]The government decided to withdraw the tanker in the hope that the hippos would move back to the swamp 60 mi away. But the hippos remained, sustained by natural water seepage and limited grass nearby.

[00:07:42]Once the surface water was gone, the competition with domestic animals ceased.

[00:07:51]A few seepage pools scattered along the 250 mi of the Betetti's dry channel are all that's left of previous flood waters.

[00:08:02]Remarkably, this pool is home to a large Nile crocodile and a saddlebill stalk.

[00:08:08]Each year, the fish are concentrated into a smaller and smaller area, and the stalk has an easy time picking them off.

[00:08:15]The crocodile has survived for 7 years, waiting for the river to return.

[00:08:21]During this time, it has protected itself in a deep burrow it has dug in the bank.

[00:08:29]Occasionally it catches a meal at the edge of the pool.

[00:08:33]These impala have come down from the makadikadi national park.

[00:08:40]Any surface water draws in wildlife from a very wide area.

[00:09:04]Nowhere in the Betetti is free of cattle. This is the only permanent surface water for thousands of square miles and people depend on it.

[00:09:14]But at this point, the riverbed forms a boundary between the national park on the east and the villages lands in the west.

[00:09:21]The unmarked boundary runs down the middle of the channel.

[00:09:33]In times of drought, animals must be resourceful and sometimes adopt unusual tactics to survive.

[00:09:44]Amazingly, a cave high up the bank is littered with hippopotamus dung.

[00:09:49]The hippo must have struggled up the bank to shade itself from the sun once its pool had dried.

[00:10:00]But without water, the hippo couldn't survive for long.

[00:10:21]Not far away, there is a pool that still has water, but it's barely fit for life.

[00:10:26]The blood red color comes from algae that thrives on hippo dung, but poisons the water.

[00:10:33]Nothing else can live in it or drink it.

[00:10:39]Desert adapted sandrass specialize in dry areas, but still need fresh water to drink.

[00:10:45]They'll fly up to 50 miles in search of a clean pool, no matter how small.

[00:10:51]While they're here, they soak special absorbent breast feathers in the water to carry droplets back to their chicks in the desert.

[00:11:03]As the channel runs alongside the park towards the makadikadi salt pans, the seepage pools become few and far between until they disappear altogether.

[00:11:20]Great seas of arid grassland lie between [music] the channel and the salt pans.

[00:11:25]These grasslands support massive freeranging [music] herds of grazers, especially wilderbeast and zebra.

[00:11:33]In the dry season, the herds are forced to live along the edge of the channel because it provides their only source of water. They visit it in their thousands, a few hundred descending at a time to drink.

[00:11:51]The betetti is a lifeline for most of the large grazing animals of the Makadikadi National Park. Even though its sandy riverbed offers little, these grazers have no other choice.

[00:12:05]Scavengers follow the wanderings of the grazers as the drought takes its toll.

[00:12:10]In the channel, the concentration of animals provides a captive audience.

[00:12:26]Competition for water becomes intense even amongst the wild herds.

[00:12:36]Water seeps into some pools so slowly that wilderbeast must pause between each sip.

[00:12:44]It's a grim existence that worsens every year the river fails.

[00:12:49]It is amazing that tens of thousands of animals are able to survive on such a small supply. Without the vast grasslands, they certainly could not.

[00:13:09]Cattle are very important to the rural Batswana people.

[00:13:14]One side of the channel is cattle country, the other national park. But without a physical boundary, the result is a free-for-all at the water holes.

[00:13:28]Like the hippos upstream, the wilderbeast live in uneasy unison with domesticated livestock.

[00:13:51]The wild grazers are timid and find it difficult to compete with domesticated animals for water.

[00:14:00]Without a boundary or fence to restrict them, the cattle also compete for grazing in the national park.

[00:14:18]There is a new arrival in the blood red pool. A baby hippopotamus nervously swims looking for its mother. It has good cause to be anxious. It is unfamiliar with the other adults. In normal conditions, it would spend the first two weeks of its life hidden from the herd, protected by its mother. But now it seems confused.

[00:14:54]Its mother briefly appears and moves her baby away from the herd.

[00:15:08]But there is nowhere for the mother to hide her calf, which is now approached by an older female.

[00:15:23]The calf seems desperate [music] for acceptance.

[00:15:43]Perhaps this behavior is a built-in [music] survival mechanism that is avoided when normal conditions prevail.

[00:15:50]Three baby hippos [music] have been killed in this way in the last year.

[00:16:02]In the dry season, the big herds of the makadikadi concentrate around the few water holes left in the channel.

[00:16:09]The big predators follow them in.

[00:16:16]Zebra normally visit at night. They're nervous of man, guns, and domestic animals.

[00:16:22]But this year, the drought is sufficiently bad to warrant a daytime visit.

[00:16:28]The lions are ready night or day.

[00:16:34]>> [laughter] >> One grazer looks much like another to a lion. They don't differentiate.

[00:16:47]Predator and prey mix freely without a fence to separate them. And the villagers are not happy with rampaging big cats near their herds.

[00:17:02]Defense Force officials have been called to investigate reports of an aggressive injured lion hanging around the channel.

[00:17:18]>> He's a handsome but wild beast and clearly will not cooperate with an inspection. So must be tranquilized first.

[00:17:27]Okay.

[00:17:38]>> Yeah.

[00:17:40]>> If his wounds can be treated, he will be transllocated within the park away from human settlements.

[00:17:59]A hole in his fur leads to a hole in his spine.

[00:18:04]>> He's been shot and his rear legs are paralyzed.

[00:18:07]The shooting was [music] probably a reprisal for a cattle kill or perhaps because he was seen too close to livestock.

[00:18:14]Either way, he has no chance of survival in the wild and is given a lethal injection.

[00:18:23]>> When the river flowed, There was at least some [music] degree of separation.

[00:18:32]But not everything is bleak in the Makadiki National Park. There is one other place that has permanent water.

[00:18:40]Far from the Betetti [music] Channel is a haven called Naipan.

[00:18:44]And here a pride of lions [music] lives free from the temptation of cattle.

[00:18:50]In the center of the pan is a small water hole kept full throughout the year. Water is pumped by the government from the underground aquifer into this tank and then to the water hole via 2 mi of buried pipeline.

[00:19:07]Spillage attracts an elephant that is learning a trick or two.

[00:19:25]It seems the elephant knows that when the tap is turned, the tank overflows.

[00:19:32]The presence of water year round allows resident communities to establish at the pan.

[00:19:40]Springbach do not normally need to drink, but doing so allows them to congregate in much larger herds in the dry season than they would otherwise be able to. The resident grazers are prey for the lions, which have a hard time hunting without cover around the water hole. But with so many springbach, there is always the chance that one will make a mistake.

[00:20:06]It's only a matter of when.

[00:20:48]>> [music] >> Wow. Wow.

[00:21:21]The male lion seems to have [music] no interest in hunting.

[00:22:07]The kill will be shared between the hunters.

[00:22:14]Or perhaps not. Lions are great opportunists, and it makes sense for the male to use his strength claiming the kill rather than exhausting it hunting on the plains.

[00:22:38]There won't be much left after he's finished, so the females must hunt again.

[00:23:01]He takes his meal to the shade of some thorn trees where he can enjoy it at his leisure.

[00:23:20]The females are not disheartened.

[00:23:54]The midday sun defeats them, but the springbach aren't going anywhere.

[00:24:09]Although there is a small water hole in the middle of night pan, the rest of the pans are dry and dusty.

[00:24:16]Strong breezes soon whip the dust into the air and dull the rays of the sun.

[00:24:23]There's little to do in a dust storm except wait for it to blow itself out.

[00:24:36]But these winds are different. There's a change in the air and the animals can sense it.

[00:24:48]Winds 100 miles to the east cross sewer pan, the largest sea of soda in Makadi Khadi. The winds are heading westward across the park.

[00:24:59]They herald the arrival of the rains and the long awaited end of the dry season.

[00:25:19]The change in atmosphere is palpable.

[00:25:28]>> [music] [music] >> rain will transform [music] Makari and bring a short but intense season of plenty.

[00:25:43][music] It's as if the lions know what good times [music] are about to come and celebrate their imminent arrival.

[00:25:52][music] Renewed grazing will bring good times for the springbach, too.

[00:26:20]The rains fall [music] sporadically as they head across the plains.

[00:26:35]At last, the long-suffering [music] hippos are freed from their tombs of caked mud.

[00:26:46]The ground softens and every footprint becomes a drinking cup.

[00:27:00]When the moon is up and the air is cool, the hippos ease themselves from their wallows for the last time.

[00:27:08]They can now leave the betetti channel and travel through the damp night towards the far-off waters of the Okabango Delta.

[00:27:36]The rains fall erratically across the park and the lower reaches of the betetti channel are still dry.

[00:27:45]Grasslands around the channel are parched, but zebra are already leaving the betetti and heading out over the plains.

[00:27:56]Wilderbeast also leave by the thousand.

[00:27:58]Even though there is no sign of water, somehow they know that pans are filling that sweet fresh water is waiting in the grasslands.

[00:28:13]Rains falling far to the east trigger this mass movement.

[00:28:18]Whether the grazers can hear low frequencies of thunder or smell the rain is not known, but in one day they all head directly towards the pans a 100 miles away.

[00:28:33]Something sends them on this journey into the great seas of grass [screaming] and the lions follow.

[00:29:10]The lions are forced to be as nomadic as the grazers. Almost all their prey has left the channel and they can avoid human harassment by leaving too.

[00:29:24]These are the [music] greatest naturally occurring herds of wilderbeast and zebra in southern Africa. Lions have little effect on their numbers.

[00:29:33]This is a journey the grazers [music] make every year the rains come and they can't wait to escape into the park.

[00:29:46]For the first time in 7 months, they can drink unaccompanied by man or cattle.

[00:30:00]Sweet water can be found amongst the salt at the broken fringes of the great pans.

[00:30:14]And as if from nowhere, streams of flamingos arrive, stopping off on their way to their breeding grounds in the largest pan.

[00:30:30]Thousands upon thousands of flamingos and [music] pelicans head for the great pan in the east of Makadiki.

[00:30:37]At the same time, the herds of grazers head towards the western edge of the pans and to Naipan [music] in the north where they join wandering elephants.

[00:30:58]The sight and smell of the fresh water excites the herds.

[00:31:08]Zebra and wilderbeast blaze trails across the Makadikadi [music] National Park. Once they're out in the open, they're finally safe. Man and his animals can't follow the herds [music] out here.

[00:31:22]They will raise their young in the isolation of the vast grasslands.

[00:31:50]The salt pans are the [music] largest in the world and rain transforms them into thousands of square miles of soda lakes.

[00:32:07]A few special places are ideal for the breeding birds where the pans are shallow, isolated, and free from predators.

[00:32:22]When the conditions are right, pelicans colonize the northern end of sewer pan, where fish are washed into the lake from the newly connected rivers.

[00:32:47]They gather in their tens of thousands to feed, mate, and raise their young before the shallow lake evaporates.

[00:33:02]The southern part of the pan is a mecca for all of southern Africa's flamingos.

[00:33:11]They arrive from the Atlantic coast of Namibia, the soda lakes of the East African Rift Valley, and possibly as far as the Indian Ocean. Hundreds of thousands of them.

[00:33:23]This is the only regular breeding site for the flamingos of southern Africa.

[00:33:36]And like the herds of grazers, they seem to know the rains are falling and time their arrival perfectly.

[00:33:54]Rains have transformed the Makari [music] Basin from a sea of soda to a vision of its shimmering past.

[00:34:06]Grass grows quickly in the lush plains that surround [music] the new soda lakes.

[00:34:16]These baab trees stand like sentinels at the edge of the pans. They may have witnessed this [music] annual transformation for the past thousand years.

[00:34:28]And some animals have made the annual journey across the plains for even longer.

[00:34:41]Adventurous bull elephants succumb to their wanderlust and follow old pathways across the plains to the renewed grasslands.

[00:34:50]They leave family groups of mothers and calves behind. Attracted here by the grass, palm fruit, and isolation.

[00:35:04]Large herds of zebra start to arrive in the rich grasslands of Naipan.

[00:35:15]The pan is now dotted with numerous water holes, and the animals no longer rely on the water pumped by the government.

[00:35:31]The wet season has inundated Makadikadi and Naipan with wildlife ready to take advantage of this time of plenty.

[00:35:40]The animals can graze and drink with ease, and their spirits seem to be lifted by their brief time in the transformed pans.

[00:35:54]In a display called proning, [music] Springbach seem to kick the dust off their dry hooves.

[00:36:18]Elephant bulls become skittish in the cool, moist air, trying each other out for size, [music] testing their strength. They enjoy life in Makadihari.

[00:36:42]Zebra [music] time most of their foing for the wet season.

[00:36:46]Those born now benefit from the abundance of food and from termite mounds that make wonderful belly [music] scratches.

[00:37:09]This female lion is in the mood for mating and solicits the dominant male.

[00:37:22]>> But this young male tries to take advantage while the dominant male is distracted.

[00:37:35]The dominant male will not tolerate any others mating in his pride.

[00:37:54]It won't be long before the young offender is driven out permanently.

[00:38:06]An adult zebra goes a lot further than a little spring box when it comes to feeding. That is some female lions switch their attention to the newly arrived big game.

[00:38:26]Lions hide strategically in the long grass to ambush zebra shepherded their way.

[00:38:46]This tactic only pays off if the zebra run in the right direction.

[00:38:57]Luckily, they have.

[00:39:06]But they're too fast for the lions.

[00:39:23]The male just watches and waits.

[00:39:33]A herd of zebra pursuing a pride of lions appears strange.

[00:39:43]But the lions are busy drinking. And with their backs in full view, there's no room for surprise.

[00:39:49]And perhaps the zebra are just curious.

[00:39:56]The male is back to his habit of hijacking kills.

[00:40:06]This time he's robbed a leopard's ladder.

[00:40:38]Pulling the kill down from the tree takes little effort compared to hunting.

[00:40:43]So, he's not going to give up easily.

[00:40:56]Half a kill is better than none and much better than exertions in the heat.

[00:41:06]Smaller predators live alongside the large.

[00:41:10][music] The trottting fox-like animal is a blackbacked jackal.

[00:41:22]While there are no other predators around the water hole, the jackal takes a chance.

[00:41:29]Jackals scavenge or hunt small mammals.

[00:41:33]They're great opportunists, but only the blackbacked hunts animals as large as Springbach.

[00:41:45]To prime himself, he settles into a heap of elephant dung, perhaps to disguise his smell.

[00:41:56]This trick seems hardly worthwhile when he remains so visible in the open country.

[00:42:18]>> [music] >> The sudden lunge scatters the adults, but surprises the youngster caught up in the mud.

[00:42:45]The prize must be taken quickly, lest an idle male lion is on the prowl.

[00:42:55]Tory eagles pose no threat to the spring box. Even their lambs are too big for it to catch.

[00:43:15]So, why is this one intent on moving the eagle along?

[00:43:20]Perhaps it's just for fun.

[00:43:30]Some of the smaller pans are already drying up when thousands of finches flock in to drink.

[00:43:46]Some young Lana falans and their parents eagerly watch them.

[00:44:07]The finches are redu quailier and the sheer numbers of them drinking means that many fledglings become water logged.

[00:44:17]And the lanners are waiting.

[00:44:27]It's time for target practice.

[00:44:34]Lanners, like all falcons, are fast, agile hunters that specialize in taking other birds.

[00:44:45]The floundering quailier give the young falcans a head start with their hunting skills, but holding on is another skill altogether.

[00:45:11]Heat. Heat.

[00:45:13][music] >> [music] [music] [music] [music] >> Quailia feed on the abundant seed in the open grasslands which they share with borrowing mircats.

[00:46:04]Mircats don't need to drink and can live in the grasslands year round, unlike the migrating quailia, wilderbeast, and zebra.

[00:46:18]Only a few inches high, the mircat baby is on its first sorty out of the den. It has a lot to learn.

[00:46:42]It takes a while to master the surprised stance of the lookout.

[00:46:56]The lanner is on the attack again.

[00:46:59]It's not interested in the adults, but it could be tempted by the youngster.

[00:47:08]And the baby hasn't mastered walking yet, let alone fleeing.

[00:47:27]But these are idle threats.

[00:47:33]Ants respond to the short-lived bounty and harvest the ripe grass seeds.

[00:47:43]After collecting the seeds, they sort them, literally separating the wheat from the chaff, then store them in their underground ladder, ready for the dry season to come.

[00:47:55]Ants and termites will eat more grass and seed than all the quail and the grazers put together.

[00:48:05]The vast grasslands attract colossal flocks of quailia, but when the water runs out, they're forced to move on.

[00:48:24]The time of plenty is short-lived, and animals make the most of it by feeding almost continuously.

[00:48:31]Already there's a change in the air.

[00:48:46]Zebra hooves raise telltale clouds of dust on the plane.

[00:49:07]the water birds have raised their young and graced the soda lakes for the last time [music] this year.

[00:49:25]Flocks of flamingos begin to stream away from the pans.

[00:49:40]Empty nests crust the pan as soda crystals begin to break through the retreating pools.

[00:49:51]When the water is too salty to drink, the herds of grazers know it's time to leave.

[00:50:00]Time to leave behind fastfading memories of sweet water pans and trudge back to the harsh realities of the betetti in the far west.

[00:50:20]With their numbers [music] reinforced by new foes, the grazers can afford the odd casualty.

[00:50:30]Already the makadikadi is unrecognizable but all too familiar.

[00:50:46]But pelicans heading for the Okavango can see new signs of hope.

[00:51:01]This year, flood waters are flowing from the Okavango into the Betetti Channel.

[00:51:06]They've traveled further than they have for 7 years.

[00:51:10]While they've still not reached the park, perhaps they signal the beginning of a wetter time.

[00:51:18]Meanwhile, plans are a foot to keep wildlife and cattle separate and bring benefits to both communities.

[00:51:25]If the floods are strong, then perhaps the river will form a major boundary for the Makadiki [music] National Park once again.

[00:52:14]>> [music]