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00:00To be continued...
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02:59To be continued...
03:29The residents can detect chemically that these tentacles are no relations of theirs.
03:35Someone else is clambering onto their stone, seeking their feeding space.
03:41This is war.
03:42The battle is difficult for us to recognize, for anemones work on a rather slower timescale than ourselves, but speed things up, and the fight becomes obvious.
03:53The lashing tentacles are armed with stings.
04:01The resident anemones have had enough, and off they go.
04:15Male strawberry frogs in the jungles of Costa Rica, when breeding time comes, fight over territory.
04:35They wrestle.
04:37They call throughout the contest.
04:57If one stops, if one stops, if he continues to call, even if he's retreating, his opponent will continue to pursue him and take him on for another round.
05:09These bouts may go on for as long as half an hour.
05:14These bouts may go on for as long as half an hour.
05:16In fact, the result is pretty well a foregone conclusion.
05:20Unless the intruder is very much bigger, the resident, the one who was here first, nearly always wins.
05:26The loser will hop off to find an unoccupied square yard of forest floor, and no great damage has been done to either contestant.
05:38But many animals can injure one another only too easily.
05:42The hummingbird, like many other animals, feeds with a device that can also be used as a weapon.
05:51Here in Trinidad, hummingbirds defend patches of flowers full of nectar on which they feed, and an owner threatens an intruder by displaying brilliant colours.
06:01But make no mistake about it, these ritualised threats are backed up with real force.
06:06Watch what happens if an intruder appears in this defended patch and stays put, as this little stuffed hummingbird presumably will do.
06:21First, the threats, spreading the tail and angling the brilliantly coloured reflected feathers on the throat and head, so that they catch the light.
06:40Usually, this is quite enough to frighten off a rival.
06:45But it's not working in this case, so now he decides to use force.
06:50And still his rival won't go.
07:02Maybe it's not a rival.
07:04Maybe it's a particularly stoical female eager to mate.
07:08So he tries that.
07:10But with such an unresponsive partner, it's difficult to find the right place to do so.
07:17Another hummingbird sees what's going on and interrupts him.
07:22So another intruder has to be seen off, and then he returns to his first problem.
07:28The needle-sharp beak, which he normally uses to thrust deep into a flower for nectar, he now wields like a murderous stiletto.
07:36It's an impressive demonstration of what can happen if an opponent doesn't give up.
07:41...
07:51...
07:52Egrets.
07:54Their beaks really are designed for killer.
07:56They're spears for stabbing.
08:01These quarrels are over roosting places.
08:05The birds have spent the day away feeding,
08:08but now in the evening they've returned to a tree
08:10where they can spend the night in the safety that comes from numbers.
08:14But some perches are better than others.
08:17No one wants the outside position,
08:19where they're at greatest risk from predators.
08:22So, again, they squabble.
08:24And again, a tool for feeding has become a weapon for aggression.
08:28But in the event, in spite of all the noise and commotion,
08:32few pecks actually land.
08:43These, too, could give a nasty nip,
08:46the biting jaws of a rove beetle.
08:49It uses them to snatch flies.
08:58But the smell of the object that attracts those flies, monkey dung,
09:06also attracts rivals.
09:08And then those jaws have a different use.
09:19Before coming to blows, the beetles also threaten one another,
09:22not with colour, like hummingbirds,
09:24but by an aggressive smell which they discharge from their abdomen.
09:37And once again, threat is all that was necessary.
09:40Better to not risk injury from those powerful jaws,
09:43if that can be avoided.
09:45There will be some more dung somewhere.
09:53This tiny pool in a tree stump in Panama
09:56is the nursery of another powerfully armed insect,
09:59a damselfly larva.
10:02Its weapons are jaws that shoot out from beneath the head.
10:07Its threats, distinctively patterned leaf-shaped gills
10:11on the end of its abdomen.
10:13Its opponent, any other damselfly larva that comes near.
10:24There's not enough food in this part of the pool for two.
10:28If they come to blows, the loser will be killed and eaten.
10:43If they come to blows, the loser will be killed and eaten.
10:56But there's enough room here for them to separate, and both survive.
11:03The Midas cichlid of Central America is not, in truth, well-armed at all.
11:09It feeds by picking off bits and pieces here and there,
11:13and it has no teeth to speak of.
11:16But its mouth can give it a hold for a trial of strength.
11:43As with frogs, if the pair are equally matched, and these are, it will be the territory owner who wins.
11:58Pincers, obviously useful for both feeding and fighting.
12:13But the pistol shrimp has one that is much larger than the other, and it uses it in a particularly damaging way.
12:23The moveable side claw cracks down on the palm with such force that the noise can stun a passing fish or an opponent.
12:32The shock knocks him senseless.
12:34But one crustacean, however, is even more.
12:35The shock knocks him senseless.
12:39But one crustacean, however, is even more powerfully armed.
12:46The shock knocks him senseless.
12:47But one crustacean, however, is even more powerfully armed.
13:01The mantis shrimp lives in burrows.
13:17The mantis shrimp lives in burrows.
13:20This female is guarding eggs and won't abandon them or her hole without a fight.
13:32Outside, a male looking for a home.
13:36Both animals can deliver a blow with their forelegs that can crack the shell of their prey or an opponent.
13:42If they're going to argue, they must be very careful.
13:55She threatens him by displaying the bold pattern on her forelegs.
14:01But he's not intimidated.
14:03He badly needs a hole to shelter from predators.
14:12He shields himself with his tail, which has specially thick armor.
14:29That foreleg, enlarged at its end into a fearsome club, is the weapon that does the damage.
14:35He's won. She's lost her eggs and her home.
14:54Considering the force of the blows that they've exchanged, she's lucky not to have lost her life as well.
14:59But male and female must meet sometime, even among mantis shrimps, if they're to breed.
15:15Once again, it's the female who is in possession of the burrow.
15:19And she is not going to surrender it willingly to anyone else.
15:38He has to convince her that he has something else in mind.
15:41She blocks the entrance with her armored tail.
15:56He tickles it, reassuring her about his intentions.
16:00Wafting his scent into the hole also helps to convince her.
16:04A quick coupling, and it's all over.
16:05A quick coupling, and it's all over.
16:06A quick coupling, and it's all over.
16:11That, in mantis shrimp terms, was comparatively easy.
16:12This male, on the same mission, is rather more apprehensive.
16:13A quick coupling, and it's all over.
16:14A quick coupling, and it's all over.
16:32That, in mantis shrimp terms, was comparatively easy.
16:36This male, on the same mission, is rather more apprehensive.
16:40She is, after all, bigger than he is, and she could crack him wide open with a single punch.
16:53Understandably, he shields himself from such a disaster.
17:00But faint hearts never did win fair ladies.
17:07She has no use for him.
17:10She's not receiving visitors today.
17:24If food gathering weapons are lethal, then their use is usually prohibited in fights between rivals.
17:43These wasps have extremely powerful stings.
17:46They lay their eggs in burrows in the ground, and stock them with caterpillars, which will serve as food for their developing young.
17:56Having found one, a female wasp paralyzes it with her sting.
18:01But caterpillars are in short supply, and others have seen it.
18:15Yet, no matter how vigorous the dispute, the wasps do not use their stings on one another.
18:28It's not worth risking death for one small caterpillar.
18:31The winner carries off her prize.
18:34A quick check below, and she's lost it.
18:44If rattlesnakes use their food collecting weapons in their fights, they might kill one another.
18:50For they have one of the most lethal of all venoms.
18:53Yet they too have their rivalries.
18:55Males meeting one another in the autumn, at the beginning of the breeding season, have arguments to settle.
19:01But their fights have rules.
19:04The aim, it seems, is not to bite your opponent, but to slam him to the ground.
19:31The aim, it seems, is not to bite your opponent.
19:50Wolves, too, could kill one another, just as they can kill a deer.
19:55But most of their disputes are settled by a complex series of gestures.
19:59Initial threats are made by lifting the lips to expose the weapons they could use, their teeth.
20:10Even when tempers flare, there is still restraint.
20:13Jaws may grip throats and heads, but they don't bite.
20:16Disputes among wolves, as among most dogs and cats, are largely a matter of threatening snarls.
20:29It's hardly surprising that meat-eaters, which have, by their very nature, to be ferocious and aggressive, should also be a bit quarrelsome on occasion.
20:44But you might think that, by contrast, grass-eaters, like these zebras, would be peaceable, gentle creatures.
20:51But actually, the male stallion zebra, on occasions, has to fight his own kind.
20:57Look at this lot.
21:03These are young males.
21:05They're just spying, practicing for the crucial duels they'll have to fight when they're adult.
21:10Then, their fights will determine their success as breeders.
21:14Now, they're largely a matter of high spirits.
21:17Since zebras don't kill other animals for food, they don't have death-dealing stings and fangs.
21:32Their only weapons are their hooves and their relatively short, blunt teeth.
21:37So, paradoxically, their fights can be very vigorous and involve a great deal of barging and nipping.
21:43That's hysteria.
21:45This legend's dangerous is called retì‚´ia.
21:47We use traumatic practice.
21:50Ladies and gentlemen!
21:55Redoubtedays of Death Cat
21:56This movement, the race with standards, few Jesus farms and wild toem BACK
22:12MUSIC PLAYS
22:37An adult breeding stallion fights in a much more determined way.
22:42He is constantly having to chase off other males who are seeking to mate with his mares.
22:47His short teeth can't give him a proper grip on an opponent's flank.
22:51The only place he can deliver a decent bite is on the neck or the legs.
22:55And the best way to protect your legs, if things get rough, is to sit on them.
22:59MUSIC PLAYS
23:00MUSIC PLAYS
23:25A retreating loser can still deliver
23:55a powerful kick in the face,
23:57so the chase isn't continued for long.
24:00And in any case, the victor won't want to go too far from his mares
24:03in case another stallion gallops in while he's away.
24:23Giraffes have no teeth at all
24:25in the front of the upper jaw,
24:26so they could hardly give a devastating bite
24:29even if they wanted to.
24:30Instead, they fight with their necks.
24:45Even here, there is restraint.
24:48A giraffe's kick can disembowel a lion.
24:51But rival giraffes never kick one another.
24:54They just use their heads like sledgehammers.
25:07Gorillas may look ferocious,
25:10but they're usually peaceable creatures.
25:12They, too, are entirely vegetarian
25:19and their teeth are hardly bigger
25:21than is necessary to rip bamboo apart.
25:25The babies spend most of their time
25:27not quarrelling,
25:29but playing amiably with one another.
25:31That, however, is a threat,
25:56a warning to a nearby group
25:57that this feeding ground is occupied.
26:01A frightening charge is usually enough
26:03to make any intruder retreat
26:05without the need for assault and battering.
26:09The young animals continue to play
26:12even when they're almost fully grown.
26:14But when you're as big and as strong as this,
26:42even minor disagreements
26:44can become a bit rough
26:45and things may get out of hand.
26:55And that's a sure sign of real fright.
26:58So best to back off showing your teeth
27:15in an attempt to retain
27:17what's left of your pride and status.
27:20Languers, like gorillas,
27:35are also strict vegetarians,
27:37though you might not think so
27:38looking at these faces.
27:40After all, you don't need huge canine teeth
27:49to masticate leaves or munch fruit.
27:52These, however, are all males.
27:58The females are much smaller animals
28:00and have no such fearsome fangs.
28:02The enlarged teeth and greater body size
28:07of the males are clear indications
28:09that these animals are fighters
28:10and that they fight over females.
28:13Even so, their formidable teeth
28:16are used much more
28:17for making noisy, grinding threats
28:19than delivering bites.
28:27Languers are not the only quarrelsome vegetarians
28:31to have developed their bodies in this way.
28:45Hippos gather their vegetation
28:47with their leathery lips
28:49and then grind it to pulp
28:51with huge molars at the back of the mouth.
28:54The tusk-like teeth in the front of the mouth,
28:57which this baby has yet to develop
28:58and which its mother already possesses,
29:01are used almost entirely
29:02in arguments between one another.
29:06The bulls have even more spectacular tusks.
29:09They yawn, not because they're tired,
29:12but to display these weapons.
29:14And if rivals don't take proper notice,
29:16they'll use them.
29:17There's really little point in risking injury
29:32if the result of a fight is predictable.
29:36So assessing the strength of your rival brings benefit all round.
29:50These Malaysian flies roosting on hanging rootlets
30:00have developed a very precise way of doing that
30:02to within a fraction of a millimetre.
30:07Their eyes are at the end of stalks
30:10that stick out sideways from their heads.
30:13They threaten with their forelegs,
30:14but the crucial factor that decides
30:16whether or not they will fight
30:18is the distance a part of their eyes.
30:21Rival males square up head to head.
30:29A bigger eye span indicates a bigger body
30:31and therefore greater strength.
30:34If a fly discovers that it's outgunned,
30:36it will back away.
30:37These, however, have established
30:44that they are equally matched.
30:46Now there will have to be a joust
30:47to get a settlement.
30:56Field crickets make their judgments
30:58largely by sound.
31:00They call
31:11by rubbing their wing cases together.
31:13After arguing so loudly and so long,
31:37the briefest contact is enough to settle things.
31:40size of claw is the criterion
31:52used by these little mud crabs.
32:04They quarrel over the ownership of a burrow.
32:10And when one is convinced that its rival is bigger,
32:36then that's that.
32:37The biggest weapons of all
32:43are developed by males who battle
32:45not over burrows, nor over food,
32:48but directly over females,
32:50as these bull elephants are doing.
32:53And if success in such battles
32:54brings the ability to mate with many females,
32:57to the exclusion of all other males
32:59who are less well armed,
33:01then male weapons over many generations
33:03will become enormous.
33:05and the battles in which they are used
33:07violent in the extreme.
33:09exactly the same process that turned elephants' teeth into tusks
33:25has created the armaments of the stag beetle.
33:41Their mandibles are so large
33:43that they can no longer be used for feeding,
33:45only for fighting.
33:46Beetle fighting technique doesn't just involve charging or pushing.
34:08instead, each tries to prize his opponent from his footholds
34:13and hurl him aside.
34:14WHISTLE BLOWS
34:15WHISTLE BLOWS
34:16WHISTLE BLOWS
34:17WHISTLE BLOWS
34:18WHISTLE BLOWS
34:19WHISTLE BLOWS
34:20WHISTLE BLOWS
34:21WHISTLE BLOWS
34:22WHISTLE BLOWS
34:23WHISTLE BLOWS
34:24WHISTLE BLOWS
34:25WHISTLE BLOWS
34:26WHISTLE BLOWS
34:27WHISTLE BLOWS
34:28WHISTLE BLOWS
34:29WHISTLE BLOWS
34:30WHISTLE BLOWS
34:31WHISTLE BLOWS
34:32WHISTLE BLOWS
34:33WHISTLE BLOWS
34:34WHISTLE BLOWS
34:35WHISTLE BLOWS
34:36WHISTLE BLOWS
34:37WHISTLE BLOWS
34:38WHISTLE BLOWS
34:39WHISTLE BLOWS
34:40WHISTLE BLOWS
34:42The Hercules Beetle is one of the biggest of all insects.
34:47It too aims to lift and throw, but its weapons are rather different.
34:52Instead of enlarging its mandibles, this beetle has grown a huge forward-pointing horn on the back of its neck.
34:59This engages with another curving upwards from the front of the head, which is moveable,
35:05so the two can be used as pincers.
35:08Few animals, in proportion to their body size, have more specialised and spectacular weapons than these five-inch monsters.
35:38That looks like the decisive throw.
35:49But no!
35:53Flies, too, develop grappling irons on their heads.
36:01These are antler flies from Australia.
36:04The rules of their fights demand that one tries to make the other topple.
36:09We are pursuing the fourth century.
36:23They will be working fully in the middle of the head.
36:27A female approaches. She has no horns.
36:57A rival male tries to intervene but is chased off. Having one, he takes his reward and guards
37:10the female while she lays the eggs that he has fertilised.
37:25A male ibex is on watch in the deserts of the Middle East. It's the beginning of the breeding
37:31season.
37:41Groups of females are scouring the mountainside searching for a few leaves to eat. The males
37:50however are seeking out one another. Who is going to rule in these mountains?
37:57First, a cautious assessment.
38:24This, impressive though it seems, is still merely a measurement of each other's strength.
38:31If one is a little less strong, there is still time for discretion to be the better part
38:38of valour. But if both decide they have a chance of winning, then battle begins.
38:42If both decide they have a chance of winning, then battle begins.
38:49If both decide they have a chance of winning, then battle begins.
38:56If both decide they are going to be the best.
39:03If both decide they have a chance of winning, then battle begins.
39:09If both decide they will be the best.
39:11If both decide they have to be the best.
39:16So, let's go.
39:46This is a dangerous country in which to fight.
39:51Sometimes a losing animal is killed by being forced over a cliff.
39:55A contestant may be so badly injured he never recovers.
40:00But when the arms race between males has equipped rivals with weapons of this size,
40:06that is the risk you must take if you are to perpetuate your genes.
40:16This is the biggest of all these kinds of weapons.
40:43It's the antler of an Alaskan bull moose.
40:47Together with its partner, it can have a spread of seven feet and weigh 70 pounds.
40:52It's so heavy and cumbersome that after the battles are over, the bull moose sheds them.
40:58It's such an impressive demonstration of strength that its mere appearance can deter a young bull.
41:05If it comes to a fight, these forward-pointing spikes are used to blind an opponent or rip a wound in his flank.
41:13This broad palm to parry thrusts from an enemy and these spikes here to act as grappling irons
41:22so that when the horns become interlocked, the contest becomes one of sheer physical strength.
41:28During these battles, the antlers are often damaged, as this one has been there and there.
41:34But that doesn't matter, because next year, new antlers are grown bigger than ever.
41:46This dominant bull has claimed half a dozen cows.
41:50A young, ambitious male approaches the harem.
42:00The resident bull keeps an eye on him.
42:20A short charge, a warning.
42:28It's enough to see him off for now, but the young stranger is persistent
42:32and continues to harass the females, attempting to isolate one.
42:50The lord of the harem thrashes the bushes, drawing attention to his huge antlers,
42:59warning the young bull not to mess with him or his females.
43:05This magnificent bull has got a radio collar on him, so we know a lot about him.
43:10The collar was put on just over three years ago,
43:13and already at that time, he was king of this part of the mountains
43:17with a group of about half a dozen females.
43:21He's kept that group with him for the past three years
43:24and been mating with them, and this is his fourth season.
43:29Bulls stand little chance of becoming dominant until they're about eight,
43:32and they seldom live for more than 12 or 13 years,
43:35so this almost certainly is his last year as king.
43:39If he wants to mate with those cows again this year,
43:42he's going to have to fight for them.
43:47So he wants to kill the whole area.
45:13The battle is over, but at great cost to both sides.
45:22The loser's antlers are badly damaged.
45:24The following day, the king himself has collapsed.
45:33Within a few hours, he will be dead.
45:35His victories live on in the multitude of foals he fathered during his reign, and his sons may develop antlers as big or even bigger than his, precisely because he was their father.
45:46But even when the genetic arms race leads to such an escalation of weaponry, most disputes may still be settled without violence.
45:55Gazelles also have formidable armaments.
46:04A stab from their horns could be lethal.
46:07Yet the mood among the bucks is very different from that among the moose.
46:11Actual battles are relatively infrequent.
46:13Rival Grant's gazelles assess one another's strengths with such care and reserve that a casual eye might not even recognize that this graceful gavotte has anything to do with conflict.
46:36They turn and nod.
46:42They resume their parallel walk.
46:52This elegant, ritualized parade is enough to convince most of the bucks in most of their disputes which of them is the victor.
47:06No conflict could be more restrained.
47:09But even among those animals who roar and snarl and brandish their weapons, most confrontations are settled with a similar lack of violence.
47:19Risking injury is the final resort.
47:22The restraint generally pays.
47:45The restraint generally pays.
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