0:00:02 > 0:00:06'The natural world is full of extraordinary animals
0:00:06 > 0:00:08'with amazing life histories.
0:00:09 > 0:00:13'Yet certain stories are more intriguing than most.'
0:00:15 > 0:00:19The mysteries of a butterfly's life cycle.
0:00:19 > 0:00:23Or the strange biology of the Emperor penguin.
0:00:23 > 0:00:26Some of these creatures were surrounded by myth
0:00:26 > 0:00:30and misunderstandings for a very long time.
0:00:30 > 0:00:34And some have only recently revealed their secrets.
0:00:34 > 0:00:38These are the animals that stand out from the crowd,
0:00:38 > 0:00:44the curiosities I find most fascinating of all.
0:00:51 > 0:00:54Some animals acquired frightening reputations
0:00:54 > 0:00:56almost as soon as they were discovered.
0:00:56 > 0:00:58In this episode,
0:00:58 > 0:01:01we investigate the stories surrounding two such creatures...
0:01:01 > 0:01:03GORILLA MOANS
0:01:03 > 0:01:06..the gorilla and the vampire bat.
0:01:06 > 0:01:09Why did they get such bad reputations?
0:01:09 > 0:01:11And were they justified?
0:01:17 > 0:01:21This statue in the London Zoo is of Guy the Gorilla.
0:01:21 > 0:01:24He was perhaps the zoo's most well-known resident
0:01:24 > 0:01:28and became one of the world's most famous gorillas.
0:01:28 > 0:01:32In his prime, Guy weighed in at over 200 kilos.
0:01:32 > 0:01:36His neck, as you can see, was thicker than a man's waist.
0:01:36 > 0:01:40He stood five feet four inches tall, over a metre and a half.
0:01:41 > 0:01:43That was with his knees bent.
0:01:43 > 0:01:48When Guy arrived here in 1940, little was known about gorillas.
0:01:48 > 0:01:50The reports from Africa hinted of
0:01:50 > 0:01:53a creature that was shockingly brutal.
0:01:53 > 0:01:54So it's hardly surprising that
0:01:54 > 0:01:58people flocked to see this fearsome monster for themselves.
0:01:58 > 0:02:02But Guy proved to be a gentle giant who won
0:02:02 > 0:02:04the affection of the public.
0:02:04 > 0:02:07So how and why did the gorilla gain
0:02:07 > 0:02:10this reputation as a fearsome savage?
0:02:12 > 0:02:16Today we know a lot about gorillas and their way of life.
0:02:16 > 0:02:19There are, in fact, a number of different kinds,
0:02:19 > 0:02:23some of which live in the lowlands and others in the mountains.
0:02:23 > 0:02:25The stay in small family groups
0:02:25 > 0:02:29and spend much of their days feeding on leaves and shoots.
0:02:31 > 0:02:34Many people, including myself, have travelled a long way to meet
0:02:34 > 0:02:37these close relatives of ours.
0:02:47 > 0:02:51Remarkably, despite being the largest living ape,
0:02:51 > 0:02:55the gorilla was one of the last to be described by science.
0:02:58 > 0:03:03In 1847, an American missionary and naturalist, Thomas Savage,
0:03:03 > 0:03:05was travelling back home from Africa
0:03:05 > 0:03:08when he stopped off to stay with some friends in the Congo.
0:03:10 > 0:03:14His friends' house was decorated with African curiosities
0:03:14 > 0:03:18and one of them caught his eye, a skull.
0:03:18 > 0:03:22But it was not like one he'd ever seen before in Africa.
0:03:22 > 0:03:27It had two huge eye sockets, a crest like a Mohawk haircut running
0:03:27 > 0:03:31from front to back and another transversely across here.
0:03:31 > 0:03:36These are anchor points for huge muscles for the jaw and neck.
0:03:36 > 0:03:41He knew immediately he was looking at a spectacular new species
0:03:41 > 0:03:43but he had no time to go in search of it.
0:03:43 > 0:03:48He frantically negotiated with some African hunters and managed to
0:03:48 > 0:03:51acquire further skulls and bones of the same kind of animal.
0:03:53 > 0:03:57When he got back to the States, Savage handed the specimens
0:03:57 > 0:03:59to an anatomist friend who immediately
0:03:59 > 0:04:02recognised that they belonged to some kind of ape.
0:04:02 > 0:04:05He gave it the scientific name, Gorilla,
0:04:05 > 0:04:08a Greek word meaning wild, hairy people.
0:04:11 > 0:04:15He then sealed the reputation of the gorilla with
0:04:15 > 0:04:19the convention of adding the surname of the person who discovered it.
0:04:19 > 0:04:22In this case, Thomas Savage.
0:04:26 > 0:04:30But many people misguidedly assumed that the scientific name,
0:04:30 > 0:04:33Gorilla savagei, was a description of the nature
0:04:33 > 0:04:35of this newly found ape.
0:04:38 > 0:04:41Though gorillas had somehow remained unknown to science
0:04:41 > 0:04:46until Victorian times, other great apes were already quite familiar.
0:04:46 > 0:04:51They were all commonly called orangs after the most famous of them,
0:04:51 > 0:04:53the orangutan, which the Dutch
0:04:53 > 0:04:58had encountered in Indonesia in the 17th century.
0:05:01 > 0:05:07Shortly afterwards, the Portuguese discovered chimpanzees in Africa
0:05:07 > 0:05:10and by the time reports of the gorilla appeared, both chimps
0:05:10 > 0:05:13and orangs had been appearing in circuses
0:05:13 > 0:05:16and the courts of European royalty for over 200 years.
0:05:21 > 0:05:26The first gorillas to arrive in Britain were dead specimens
0:05:26 > 0:05:31and unlike these late arrivals, they will often badly preserved.
0:05:31 > 0:05:35They went on display at the Crystal Palace and their grotesque
0:05:35 > 0:05:38appearance was supported by horrific accounts of their nature.
0:05:41 > 0:05:44One of the early collectors of gorillas was an American
0:05:44 > 0:05:46anthropologist called Du Chaillu.
0:05:47 > 0:05:51He made numerous expeditions to Africa and returned with
0:05:51 > 0:05:54tales of terrifying encounters with gorillas.
0:05:56 > 0:06:02In this, his bestseller, Exploration And Adventure In Equatorial Africa,
0:06:02 > 0:06:07amongst sensational tales of cannibalism, charging buffalo
0:06:07 > 0:06:10and tropical fevers, is the very first eyewitness
0:06:10 > 0:06:14account of man meeting male gorillas in their jungle home.
0:06:15 > 0:06:19"He was a sight, I think, I shall never forget.
0:06:19 > 0:06:21"Nearly six feet high with immense body,
0:06:21 > 0:06:25"huge chest and great, muscular arms,
0:06:25 > 0:06:29"with fiercely glaring, large, deep grey eyes and a hellish
0:06:29 > 0:06:34"expression of face that seemed, to me, like some nightmare vision.
0:06:34 > 0:06:39"Thus stood before us this king of the African forest."
0:06:39 > 0:06:43To be fair, Chaillu did dispel some of the more ridiculous stories
0:06:43 > 0:06:46and myths about the gorilla, but his compelling
0:06:46 > 0:06:50tales of their fierce nature was just what the public wanted to hear.
0:06:53 > 0:06:54GORILLA CALLS
0:06:56 > 0:06:59Du Chaillu's vivid description of the gorilla in the wild
0:06:59 > 0:07:04reinforced its image as a fearsome beast and confirmed its reputation.
0:07:08 > 0:07:10GORILLA CALLS
0:07:13 > 0:07:17These displays may look fearsome, but in fact,
0:07:17 > 0:07:20they're only rarely followed by physical violence.
0:07:22 > 0:07:25Du Chaillu's description may have wowed readers,
0:07:25 > 0:07:29but the scientific establishment were rather less easy to impress.
0:07:29 > 0:07:34He was branded a braggart, a plagiarist and a charlatan.
0:07:34 > 0:07:37Some suggested he never even visited Africa
0:07:37 > 0:07:41and that his ferocious creatures were, in fact, gentle.
0:07:41 > 0:07:44But he had his strongest support right at the top.
0:07:44 > 0:07:48Professor Richard Owen, founder of the London Natural History Museum.
0:07:51 > 0:07:54Owen was one of the most respected figures
0:07:54 > 0:07:58of Victorian science, but also one of the most widely disliked.
0:07:58 > 0:08:02He was vehemently opposed to Darwin's theory of evolution,
0:08:02 > 0:08:06which suggested that apes and humans were closely related.
0:08:08 > 0:08:12Du Chaillu's description of a ferocious gorilla suited Owen,
0:08:12 > 0:08:15because it seemed to support his view that we could not
0:08:15 > 0:08:18possibly be related to such dreadful monsters.
0:08:19 > 0:08:21But he could hardly deny the anatomical
0:08:21 > 0:08:24similarity between gorillas and humans.
0:08:25 > 0:08:30This illustration from 1855, shows the skeleton of a man
0:08:30 > 0:08:32and gorilla side-by-side.
0:08:32 > 0:08:34It was published by Owen himself
0:08:34 > 0:08:37and makes clear the likeness between the two species.
0:08:43 > 0:08:47But Owen was still not willing to accept that man could have
0:08:47 > 0:08:49ape-like ancestors.
0:09:00 > 0:09:05In 1860, a great debate about evolution and man's place
0:09:05 > 0:09:10in the natural world took place in this very room in Oxford.
0:09:10 > 0:09:13Richard Owen presented compelling evidence for the presence of
0:09:13 > 0:09:19three structures in the human brain that were absent in a gorilla's.
0:09:19 > 0:09:23According to Owen, this made the descent of man from apes impossible.
0:09:24 > 0:09:27As the only anatomist with access to gorilla specimens,
0:09:27 > 0:09:29he was confident he was on firm ground,
0:09:29 > 0:09:34but he hadn't counted on biologist Thomas Henry Huxley.
0:09:35 > 0:09:40Huxley, known as Darwin's bulldog, was, in his own words,
0:09:40 > 0:09:45waiting for this opportunity to nail that mendacious humbug, Owen,
0:09:45 > 0:09:50like a kite to a barn door, and immediately challenged his
0:09:50 > 0:09:52findings, vowing to prove him wrong.
0:09:52 > 0:09:55In the years that followed, Huxley doggedly pursued Owen
0:09:55 > 0:09:58and did indeed prove him wrong on all counts.
0:09:58 > 0:10:02He found all three brain structures in the apes
0:10:02 > 0:10:06and proved apes were closer to men than to monkeys.
0:10:06 > 0:10:11Richard Owen had, according to Huxley, been guilty of wilful
0:10:11 > 0:10:13and deliberate falsehood.
0:10:18 > 0:10:21Owen and Du Chaillu's misleading descriptions of the gorilla
0:10:21 > 0:10:24failed to disprove our relationship to apes.
0:10:26 > 0:10:28On the contrary, they became a turning point
0:10:28 > 0:10:32in our acceptance that they are our cousins.
0:10:36 > 0:10:39But, sadly, the damage to the gorilla's reputation had
0:10:39 > 0:10:41already been done.
0:10:46 > 0:10:50When Guy arrived in London almost 100 years after the discovery
0:10:50 > 0:10:56of gorillas, people still regarded him as a fearsome and savage beast.
0:11:03 > 0:11:06It took the next 30 years of Guy's life for a more accurate
0:11:06 > 0:11:08picture of the gorilla to emerge.
0:11:08 > 0:11:13Although gorillas can, indeed, be dangerous when angry or threatened,
0:11:13 > 0:11:16most of the time, they are mild and peaceful creatures
0:11:16 > 0:11:20and nowhere is this shown more clearly than in a charming story
0:11:20 > 0:11:22from Guy's time here at the zoo.
0:11:22 > 0:11:27Guy's cage often attracted sparrows that then became trapped inside.
0:11:27 > 0:11:31But rather than kill them, Guy would lift the tiny birds
0:11:31 > 0:11:35carefully onto his hand, examine them and then release them.
0:11:35 > 0:11:37He was, indeed, a gentle giant.
0:11:42 > 0:11:45Over time, thanks to the determination of field researchers
0:11:45 > 0:11:50like Dian Fossey, people have seen another side to gorillas.
0:11:57 > 0:12:01By the time I met them, many of us were ready to see them
0:12:01 > 0:12:04not as savages, but as animals that are equally
0:12:04 > 0:12:07suited to their environment as we are to ours.
0:12:13 > 0:12:18So, now, at last, the gorilla, which was once labelled a fearsome
0:12:18 > 0:12:22beast, has managed to shake off its undeserved reputation.
0:12:28 > 0:12:34Our second subject, the vampire bat, has also had an undeservedly
0:12:34 > 0:12:39bad reputation and been the inspiration behind tales of evil.
0:12:42 > 0:12:46Bats have had a bad reputation for a very long time.
0:12:46 > 0:12:51As creatures of the night, they are connected with dark mysteries
0:12:51 > 0:12:53and devilish goings-on.
0:12:53 > 0:12:56But there was never any real evidence to support these
0:12:56 > 0:12:59claims of their evil nature, that is
0:12:59 > 0:13:02until the Conquistadors returned from South America with
0:13:02 > 0:13:07tales of giant bats that dropped down on you as you slept
0:13:07 > 0:13:10and sucked the very blood from your veins.
0:13:10 > 0:13:12Tales of vampire bats.
0:13:15 > 0:13:18Stories of giant, bloodsucking bats have long been
0:13:18 > 0:13:22part of the culture of South American people.
0:13:22 > 0:13:25Images of them with savage fangs are common
0:13:25 > 0:13:28and a bat god was associated with death.
0:13:30 > 0:13:34But it wasn't until the 18th century that a detailed description of a
0:13:34 > 0:13:39vampire bat was published in Europe and it came from one of its victims.
0:13:42 > 0:13:46An Englishman by the name of John Gabriel Stedman came
0:13:46 > 0:13:51back from South America with reports of having been bitten by a vampire.
0:13:53 > 0:13:57He described a bat of monstrous size that sucked the blood of men
0:13:57 > 0:13:59and cattle when they're fast asleep.
0:13:59 > 0:14:03And he proudly declared that he'd managed to catch the beast
0:14:03 > 0:14:04and cut off its head.
0:14:05 > 0:14:08Stedman's descriptions were detailed,
0:14:08 > 0:14:10but nonetheless misleading.
0:14:10 > 0:14:13His drawing shows, in fact, the bat that feeds on nectar
0:14:13 > 0:14:15and is only a few centimetres long.
0:14:17 > 0:14:21He had been bitten by a vampire, but he had blamed the wrong bat.
0:14:25 > 0:14:30Clouded by their own ideas of what a vampire should look like,
0:14:30 > 0:14:34early naturalists jumped to all sorts of conclusions and assumed
0:14:34 > 0:14:39that it was the biggest and the most ugly that were the bloodsuckers.
0:14:39 > 0:14:43In fact, the name "vampire" was sometimes given to bats that
0:14:43 > 0:14:47looked the part, but had never so much as sniffed blood.
0:14:47 > 0:14:50These bats, for example, drawn by the 19th-century German
0:14:50 > 0:14:54naturalist Ernst Haeckel, belonged to a group called
0:14:54 > 0:14:58the leaf nosed bats, because of these strange protrusions
0:14:58 > 0:15:00around the end of the nose.
0:15:00 > 0:15:03This gives them a particularly menacing appearance and some early
0:15:03 > 0:15:08naturalists thought the nose leaf was, in fact, the mark of a vampire.
0:15:10 > 0:15:13The leaflike object on its nose was thought to be so sharp,
0:15:13 > 0:15:17the bat could use it to puncture a victim's skin,
0:15:17 > 0:15:20and since many bats have such nose leaves,
0:15:20 > 0:15:25over 100 species were mistakenly described as vampires.
0:15:25 > 0:15:28In fact, the nose leaf is made of nothing more than soft flesh
0:15:28 > 0:15:31and couldn't possibly draw blood.
0:15:31 > 0:15:33It's used for echolocation.
0:15:35 > 0:15:37Echolocation works like sonar.
0:15:37 > 0:15:41The bats produce high-frequency calls and use the returning
0:15:41 > 0:15:44echoes to build up a mental map of their surroundings,
0:15:44 > 0:15:48so they are able to find their way in the pitch dark and hunt for prey.
0:15:50 > 0:15:53Most bats produce these calls in their throats,
0:15:53 > 0:15:57but leaf nosed bats project them out through their nose in a beam.
0:15:59 > 0:16:03By doing so, they can feed and echolocate at the same time.
0:16:09 > 0:16:12So many leaf nosed bats had been discovered that the arrival
0:16:12 > 0:16:16in Europe of a specimen of another, smaller species
0:16:16 > 0:16:19in 1810 attracted very little attention.
0:16:19 > 0:16:22It was simply named Desmodus rotundus,
0:16:22 > 0:16:25on account of it being a little portly.
0:16:26 > 0:16:29Some 30 years later, when Charles Darwin was travelling
0:16:29 > 0:16:31around the world aboard the Beagle,
0:16:31 > 0:16:36he observed Desmodus feeding in the wild for the first time.
0:16:36 > 0:16:40He saw it drinking the blood of sleeping horses and cattle.
0:16:41 > 0:16:45He had, at last, identified the true vampire.
0:16:47 > 0:16:50We know that there are only three species of vampire bats
0:16:50 > 0:16:53and they all live in South America.
0:16:53 > 0:16:57They're totally unique in being the only mammals to feed exclusively
0:16:57 > 0:17:01on blood, but feeding on blood is not as easy as you might think.
0:17:01 > 0:17:04It's actually a pretty challenging diet.
0:17:04 > 0:17:09Blood is made up of water and protein and has virtually no fat,
0:17:09 > 0:17:13so, vampires find it hard to get enough energy.
0:17:13 > 0:17:16They must consume 50% of their own body weight in blood each night,
0:17:16 > 0:17:19or they'll die within a few days.
0:17:24 > 0:17:28Under the cover of darkness, the vampire sets out to hunt.
0:17:33 > 0:17:40The nose leaf and echolocation help it to home in on its prey.
0:17:46 > 0:17:48The bat approaches carefully.
0:17:48 > 0:17:51Unlike most other bats, it can use its wings as legs
0:17:51 > 0:17:53and it walks on its elbows.
0:18:01 > 0:18:05Once near its victim, it uses its nose leaf in another way.
0:18:07 > 0:18:09It acts as a heat-seeking device,
0:18:09 > 0:18:11guiding the bat to the warmth of its prey.
0:18:15 > 0:18:19Today, livestock have largely replaced wild jungle animals,
0:18:19 > 0:18:23but even livestock can be dangerous to a small bat.
0:18:29 > 0:18:34Patiently, the vampire stalks its prey.
0:18:37 > 0:18:40And, at last, it's close enough.
0:18:40 > 0:18:43The teeth are so sharp that a nick is all that's needed.
0:18:47 > 0:18:53Blood from the wound doesn't clot, but continues to flow, and within
0:18:53 > 0:18:57a quarter of an hour, the bat can drink 40% of its body weight.
0:18:59 > 0:19:02That is the equivalent to one of us drinking over 20 litres.
0:19:07 > 0:19:11Having had its fill, it's back to the roost.
0:19:14 > 0:19:17Finding a meal every night is not easy,
0:19:17 > 0:19:20but vampires have come up with a solution to that problem.
0:19:20 > 0:19:24Those which have been successful share the blood they've drunk
0:19:24 > 0:19:26with those who had failed to collect any.
0:19:28 > 0:19:31Vampires are most likely to share with those
0:19:31 > 0:19:35they know well from roosting and grooming together.
0:19:35 > 0:19:37It's an act of apparent kindness,
0:19:37 > 0:19:40but the colony, as a whole, benefits.
0:19:42 > 0:19:46So, it seems that there is another, gentler side to these bats
0:19:46 > 0:19:48than anyone could have imagined.
0:19:50 > 0:19:54Unfortunately, just as light was being shed on the true
0:19:54 > 0:19:57nature of the vampire, an Irish novelist published the book
0:19:57 > 0:20:01that would seal their reputation for the foreseeable future.
0:20:01 > 0:20:06Bram Stoker's classic, Dracula, leaves little doubt as to
0:20:06 > 0:20:08where his inspiration came from.
0:20:10 > 0:20:14His story combined European myths of vampires that come to haunt
0:20:14 > 0:20:18the living, with stories of bloodsucking bats
0:20:18 > 0:20:22from South America, and it's an association that the real
0:20:22 > 0:20:25vampire bats have struggled to shed.
0:20:34 > 0:20:38More recently, vampire bats have made headlines once again.
0:20:38 > 0:20:42It's been discovered that their saliva contains the remarkable
0:20:42 > 0:20:46blood-thinning agent that's been named Draculin.
0:20:46 > 0:20:49And it's proving to be the most successful treatment
0:20:49 > 0:20:50for stroke victims.
0:20:50 > 0:20:54How ironic that a creature we once believed to be a deadly threat
0:20:54 > 0:20:58may turn out to save human lives in the future.
0:20:58 > 0:21:02Maybe it's time we re-evaluated the reputation of the much
0:21:02 > 0:21:04maligned vampire bat.
0:21:07 > 0:21:11Vampire bats and gorillas were long pursued by unfair reputations,
0:21:11 > 0:21:16but while our fear of gorillas has turned into respect and admiration,
0:21:16 > 0:21:21the vampire bat, for many of us, continues to evoke mixed emotions.