Would you like to inspect the original subtitles? These are the user uploaded subtitles that are being translated:
1
00:00:17,523 --> 00:00:19,979
The natural world is full of colours...
2
00:00:26,754 --> 00:00:28,939
...colours that attract attention...
3
00:00:34,904 --> 00:00:37,799
...colours that blend beautifully with their background...
4
00:00:41,494 --> 00:00:44,929
...and colours that create extraordinary displays.
5
00:00:50,984 --> 00:00:54,518
There are few animals more brilliantly coloured than
6
00:00:54,543 --> 00:00:56,079
these scarlet macaws.
7
00:00:57,343 --> 00:01:01,359
Animals can use colour for all kinds of different reasons,
8
00:01:01,384 --> 00:01:05,109
and some have colours that we ourselves can't even see.
9
00:01:08,134 --> 00:01:12,318
But with new cameras, some developed especially for this series,
10
00:01:12,343 --> 00:01:16,518
we can reveal a world that has long been hidden from our eyes...
11
00:01:18,704 --> 00:01:22,109
...a world of colours that only some animals can see.
12
00:01:23,854 --> 00:01:29,318
Secret communication channels for the most private of messages,
13
00:01:29,343 --> 00:01:33,318
and colours so bold and brilliant they dazzle our senses.
14
00:01:36,384 --> 00:01:37,599
Whether to win a mate...
15
00:01:39,744 --> 00:01:40,959
...or beat a rival...
16
00:01:43,064 --> 00:01:44,318
...to warn off an enemy...
17
00:01:46,184 --> 00:01:47,648
...or to hide from one...
18
00:01:52,824 --> 00:01:57,359
...we will reveal extraordinary stories about life in colour.
19
00:02:23,494 --> 00:02:26,109
The rocky hills of Southern India.
20
00:02:34,624 --> 00:02:37,829
The stage is set for a performance of one
21
00:02:37,854 --> 00:02:41,679
of the most spectacular dances in the natural world.
22
00:02:41,704 --> 00:02:43,999
PEACOCKS CALL
23
00:02:46,744 --> 00:02:48,438
Peacocks are gathering.
24
00:03:02,954 --> 00:03:07,959
This, surely, is one of the most glamorous of all sights in nature.
25
00:03:16,024 --> 00:03:19,679
150 shimmering eyespots,
26
00:03:19,704 --> 00:03:22,959
carried on tail feathers that are six feet long.
27
00:03:33,574 --> 00:03:36,648
So how did such glories evolve?
28
00:03:40,874 --> 00:03:43,749
It seems it's all down to the female.
29
00:03:47,774 --> 00:03:49,109
HE CALLS
30
00:03:51,984 --> 00:03:55,879
The brighter a male's colours and the greater the number of
31
00:03:55,904 --> 00:03:59,959
his feathery eyespots, the more attractive she will find him.
32
00:04:12,854 --> 00:04:16,648
But colours and plumes like these come at a cost.
33
00:04:24,774 --> 00:04:27,959
The immense tail makes flying difficult -
34
00:04:27,984 --> 00:04:31,318
the males are literally weighed down by their feathers.
35
00:04:35,824 --> 00:04:39,318
Yet the colours they carry are clearly very important to them.
36
00:04:42,024 --> 00:04:45,518
So why and how has colour taken on such value?
37
00:04:52,954 --> 00:04:58,318
To understand that, we have to think back to when it all began.
38
00:05:02,543 --> 00:05:07,079
700 million years ago, our planet was far less colourful.
39
00:05:08,984 --> 00:05:11,159
But the first animals, it seems,
40
00:05:11,184 --> 00:05:15,188
had eyes that were unable to distinguish colours anyway.
41
00:05:17,744 --> 00:05:20,159
Gradually, however, this changed.
42
00:05:26,954 --> 00:05:28,438
I am in Costa Rica...
43
00:05:30,854 --> 00:05:34,188
...a good place to see how valuable colour can be.
44
00:05:38,624 --> 00:05:43,518
This toucan likes fruit, and its ability to choose ripe
45
00:05:43,543 --> 00:05:49,209
fruit from unripe depends on colour because the ripe ones are black.
46
00:05:51,384 --> 00:05:55,359
And this capacity of choosing between different colours was
47
00:05:55,384 --> 00:05:59,648
a very important stage in the evolution of colour vision.
48
00:06:06,184 --> 00:06:10,999
Birds, close relatives of dinosaurs, appeared before mammals.
49
00:06:15,904 --> 00:06:20,109
The first mammals, as far as we can tell, were mostly nocturnal.
50
00:06:21,314 --> 00:06:24,359
Colours are not easily distinguishable at night,
51
00:06:24,384 --> 00:06:26,648
so why evolve the ability to detect them?
52
00:06:30,423 --> 00:06:35,099
So it seems that the first mammals themselves were not very colourful.
53
00:06:36,593 --> 00:06:39,039
And this is still largely true today.
54
00:06:43,423 --> 00:06:45,879
Most are shades of black and white...
55
00:06:47,423 --> 00:06:48,438
...or brown.
56
00:06:52,343 --> 00:06:53,929
But there are exceptions.
57
00:06:55,213 --> 00:06:58,959
And one of the most dramatic lives in the forests of Gabon
58
00:06:58,984 --> 00:06:59,999
in West Africa.
59
00:07:15,673 --> 00:07:18,999
These monkeys are mandrills - a kind of baboon.
60
00:07:20,264 --> 00:07:21,749
They live in large troops.
61
00:07:23,423 --> 00:07:27,929
Most are females and youngsters, both of which are brown.
62
00:07:31,954 --> 00:07:33,879
But the males are different.
63
00:07:37,673 --> 00:07:42,209
They, when they're young, have very plain faces with naked muzzles.
64
00:07:47,234 --> 00:07:50,239
As they grow, their faces begin to change.
65
00:07:53,104 --> 00:07:56,188
Testosterone begins to flow through their veins.
66
00:08:02,314 --> 00:08:05,929
When they're about six years old, they leave the troop
67
00:08:05,954 --> 00:08:07,829
and start to fend for themselves.
68
00:08:09,213 --> 00:08:13,679
As they become sexually mature, colour appears in their faces...
69
00:08:15,494 --> 00:08:16,999
...and what colour!
70
00:08:26,624 --> 00:08:30,159
Mandrill males are the biggest of all monkeys...
71
00:08:32,104 --> 00:08:34,318
...weighing over 30 kilos -
72
00:08:34,343 --> 00:08:37,879
enormously, frighteningly powerful.
73
00:08:37,904 --> 00:08:39,239
And their colours say so.
74
00:08:42,264 --> 00:08:44,109
SCREECHING
75
00:08:45,213 --> 00:08:46,209
HISSING
76
00:08:48,064 --> 00:08:50,879
It is not only his face which is coloured.
77
00:08:53,343 --> 00:08:54,699
So is his rump.
78
00:08:56,084 --> 00:09:00,408
Both are fearless declarations of his health and strength.
79
00:09:04,483 --> 00:09:08,769
And this male is more than happy to prove just how strong he is...
80
00:09:08,794 --> 00:09:11,619
...should any male dare to challenge him.
81
00:09:16,233 --> 00:09:20,259
Not surprisingly, mandrill eyes are particularly sensitive to colour.
82
00:09:24,693 --> 00:09:28,208
And it's the brightness of their colours which signals their status.
83
00:09:33,924 --> 00:09:35,129
SCREECHING
84
00:09:38,683 --> 00:09:41,099
There are four males in this troop,
85
00:09:41,124 --> 00:09:43,309
and they're constantly flexing their muscles
86
00:09:43,334 --> 00:09:47,408
and displaying their colours to establish who is the strongest.
87
00:09:51,204 --> 00:09:54,208
And not all disputes are settled peacefully.
88
00:10:00,613 --> 00:10:03,408
They emphasise their ferocity by gestures
89
00:10:03,433 --> 00:10:05,458
such as grinding their teeth.
90
00:10:13,084 --> 00:10:16,769
If that doesn't work, the highest-ranking male will fight...
91
00:10:19,254 --> 00:10:20,789
...and the others know it.
92
00:10:25,394 --> 00:10:28,069
It's better to let colour do the talking.
93
00:10:30,403 --> 00:10:31,539
HE COUGHS
94
00:10:36,453 --> 00:10:39,628
Mandrills see the world much as we do
95
00:10:39,653 --> 00:10:42,558
and have three kinds of colour-sensitive cells.
96
00:10:45,974 --> 00:10:49,789
But another group of animals has colour vision that's far
97
00:10:49,814 --> 00:10:53,669
superior to that of any mammal - birds.
98
00:11:00,533 --> 00:11:04,099
Their ability varies from group to group,
99
00:11:04,124 --> 00:11:06,819
but you can judge how good they are from the colours
100
00:11:06,844 --> 00:11:08,949
they use to signal to one another.
101
00:11:11,224 --> 00:11:14,349
Hummingbirds have excellent colour vision...
102
00:11:15,974 --> 00:11:21,029
...because that enables them to spot brightly-coloured flowers
103
00:11:21,054 --> 00:11:23,508
which contains the nectar on which they feed.
104
00:11:32,453 --> 00:11:36,459
So this artificial feeder is a big success -
105
00:11:36,484 --> 00:11:38,789
brightly coloured down here,
106
00:11:38,814 --> 00:11:42,349
and containing sugar solution, artificial nectar, up there.
107
00:11:48,533 --> 00:11:51,628
But hummingbirds also use their ability to see
108
00:11:51,653 --> 00:11:55,589
colour in a different way - to attract a mate.
109
00:11:58,174 --> 00:12:00,869
Most species live in South America, where
110
00:12:00,894 --> 00:12:04,069
there are flowers of some sort all year round.
111
00:12:07,844 --> 00:12:10,308
A few, however, have spread northwards
112
00:12:10,333 --> 00:12:13,029
into the deserts of the American Southwest.
113
00:12:17,333 --> 00:12:21,539
In this vastness, it's hard to get noticed...
114
00:12:23,814 --> 00:12:27,869
...especially if you are a small hummingbird looking for a mate.
115
00:12:40,653 --> 00:12:45,919
But this male Costa's hummingbird uses his colours to send
116
00:12:45,944 --> 00:12:46,949
a SGCFGt ITIGSSGQG.
117
00:12:50,453 --> 00:12:55,099
Out in the open, flashy colours can attract unwanted attention,
118
00:12:55,124 --> 00:12:57,819
so he keeps them hidden most of the time.
119
00:13:00,014 --> 00:13:01,919
A slight turn of the head, however,
120
00:13:01,944 --> 00:13:05,558
provides a tantalising glimpse of what he has to offer.
121
00:13:10,614 --> 00:13:12,869
He's spotted a female.
122
00:13:12,894 --> 00:13:13,919
She's feeding.
123
00:13:20,694 --> 00:13:25,149
Hummingbirds live fast lives and need plenty of fuel.
124
00:13:25,174 --> 00:13:27,589
So, if he is to attract her attention,
125
00:13:27,614 --> 00:13:29,949
he needs something eye-catching.
126
00:13:35,814 --> 00:13:38,669
Time to reveal his colours!
127
00:13:42,124 --> 00:13:45,279
Erecting the iridescent feathers on his neck,
128
00:13:45,304 --> 00:13:48,149
he positions himself to catch the sunlight.
129
00:13:55,614 --> 00:13:59,279
Seen at just the right angle, his colours are dazzling.
130
00:14:18,944 --> 00:14:21,919
Aerobatics like these take a lot of energy,
131
00:14:21,944 --> 00:14:26,069
so his performance can give her clues about his health and fitness.
132
00:14:31,203 --> 00:14:36,349
Every second she takes to decide burns up his energy reserves...
133
00:14:41,844 --> 00:14:43,949
...so he can only hover for so long.
134
00:15:02,453 --> 00:15:06,428
At last, his colours have persuaded her.
135
00:15:16,014 --> 00:15:19,178
Displaying your colours is easy out in the open.
136
00:15:23,894 --> 00:15:26,539
Birds which live in dark forests, however,
137
00:15:26,564 --> 00:15:28,989
have to work harder to get noticed.
138
00:15:34,814 --> 00:15:37,739
The rainforests of New Guinea.
139
00:15:37,764 --> 00:15:40,558
Here, the trees stand 100 feet tall,
140
00:15:40,583 --> 00:15:43,949
with their crowns forming a near continuous canopy.
141
00:15:46,864 --> 00:15:49,949
But here and there, there's a small gap through which
142
00:15:49,974 --> 00:15:53,349
a shaft of light illuminates a patch on the forest floor...
143
00:15:56,694 --> 00:15:59,029
...a stage for one of the most versatile
144
00:15:59,054 --> 00:16:01,069
dancers in the natural world...
145
00:16:05,014 --> 00:16:06,349
...a bird of paradise.
146
00:16:08,403 --> 00:16:10,558
There are over 30 different species.
147
00:16:10,583 --> 00:16:12,428
This one, understandably,
148
00:16:12,453 --> 00:16:15,869
is called the magnificent bird of paradise.
149
00:16:17,403 --> 00:16:18,428
A male.
150
00:16:22,014 --> 00:16:25,508
Before starting his show, he clears his stage.
151
00:16:27,694 --> 00:16:31,349
The bare brown earth will make his colours stand out better.
152
00:16:46,333 --> 00:16:51,039
He takes particular care to remove anything green.
153
00:16:51,064 --> 00:16:54,275
That colour will be the main feature of his display,
154
00:16:54,300 --> 00:16:56,316
and he doesn't want any competition.
155
00:17:00,390 --> 00:17:01,906
Satisfied at last.
156
00:17:03,601 --> 00:17:07,615
A sapling in the centre will serve as his dancing pole.
157
00:17:13,190 --> 00:17:15,365
His costume must be immaculate.
158
00:17:17,161 --> 00:17:19,446
Plumes like these need careful attention.
159
00:17:32,390 --> 00:17:34,415
Time to summon the audience.
160
00:17:36,320 --> 00:17:43,545
HE CHIRPS
161
00:17:48,111 --> 00:17:50,295
HE CHIRPS
162
00:17:55,721 --> 00:17:58,806
The first to appear are all young males.
163
00:18:01,211 --> 00:18:05,165
They won't develop their colours until they're seven years old.
164
00:18:05,190 --> 00:18:07,576
They have come to watch and to learn.
165
00:18:09,390 --> 00:18:12,446
HE CHIRPS
166
00:18:13,881 --> 00:18:15,365
At last, a female.
167
00:18:16,551 --> 00:18:19,295
She looks much like a young male to our eyes...
168
00:18:21,281 --> 00:18:23,446
...but he can clearly tell the difference.
169
00:18:28,440 --> 00:18:30,615
She willjudge him by his performance
170
00:18:30,640 --> 00:18:32,906
and the brightness of his feathers.
171
00:18:35,440 --> 00:18:38,216
She does that from directly above him.
172
00:18:52,570 --> 00:18:57,186
He puffs up his feathers and swings round to show her his colours.
173
00:19:03,361 --> 00:19:07,415
For years, naturalists only watched his performance from ground level.
174
00:19:13,881 --> 00:19:16,365
But the female does so from above.
175
00:19:21,751 --> 00:19:25,336
And from there, his brilliant green colours stand out
176
00:19:25,361 --> 00:19:27,415
vividly against the brown of the ground.
177
00:19:32,111 --> 00:19:36,726
A pair of bare, quivering quills sprouting from his tail
178
00:19:36,751 --> 00:19:38,216
add to the excitement.
179
00:19:43,211 --> 00:19:47,576
This is one of the most complex of all courtship dances, and we're
180
00:19:47,601 --> 00:19:51,656
still unaware of the details that she may regard as critical.
181
00:20:02,601 --> 00:20:05,776
The prize-giving, however, is unmistakable.
182
00:20:19,390 --> 00:20:21,906
The colour vision of birds is mostly excellent.
183
00:20:24,390 --> 00:20:27,165
But that of many insects is almost as good.
184
00:20:34,520 --> 00:20:35,526
Butterflies.
185
00:20:42,111 --> 00:20:46,806
They too have evolved an astonishing variety of colours and patterns.
186
00:20:59,751 --> 00:21:04,656
The wings are covered by tiny scales like tiles on a roof,
187
00:21:04,681 --> 00:21:07,216
and it's they that produce some of the colours.
188
00:21:11,831 --> 00:21:13,256
Some have pigments.
189
00:21:14,931 --> 00:21:20,136
Others reflect light to produce a shimmering iridescence with
190
00:21:20,161 --> 00:21:23,936
colours that change according to the angle from which they are viewed.
191
00:21:36,931 --> 00:21:41,856
But some butterflies use colours that are invisible to our eyes.
192
00:21:50,961 --> 00:21:55,615
The glorious colours of an English meadow in bloom is
193
00:21:55,640 --> 00:21:57,856
a delight to the eyes of many of us.
194
00:21:59,111 --> 00:22:02,906
But their purpose is not to appeal to us -
195
00:22:02,931 --> 00:22:07,495
it's to attract insects, such as butterflies and bees.
196
00:22:09,751 --> 00:22:15,446
Most of these plants depend on insects to pollinate them,
197
00:22:15,471 --> 00:22:19,056
and they use their bright colours in order to attract insects.
198
00:22:20,161 --> 00:22:23,976
But to understand what an insect sees,
199
00:22:24,001 --> 00:22:27,545
we have to be able to see it through their eyes and from
200
00:22:27,570 --> 00:22:32,086
their perspective, and happily we've got a camera that enables us
201
00:22:32,111 --> 00:22:33,256
to do just that.
202
00:22:37,931 --> 00:22:40,006
This camera set-up lets us look at
203
00:22:40,031 --> 00:22:42,216
that flower in two different ways.
204
00:22:43,681 --> 00:22:46,256
This camera is an ultraviolet camera
205
00:22:46,281 --> 00:22:48,806
because it has a filter there that
206
00:22:48,831 --> 00:22:51,806
only lets through ultraviolet light.
207
00:22:51,831 --> 00:22:54,165
But at the same time, this filter
208
00:22:54,190 --> 00:22:56,365
also reflects normal light,
209
00:22:56,390 --> 00:23:00,576
and that comes into this camera, and that shows what we can see.
210
00:23:00,601 --> 00:23:05,256
So I can compare the two very easily. That's what we can see...
211
00:23:09,211 --> 00:23:10,936
...and that's what the insect sees.
212
00:23:14,001 --> 00:23:16,976
Flowers have evolved these ultraviolet markings
213
00:23:17,001 --> 00:23:20,526
for the benefit of insects, such as butterflies.
214
00:23:29,931 --> 00:23:34,976
This particular one lives in the rainforests of eastern Australia.
215
00:23:35,001 --> 00:23:38,136
It's a blue moon butterfly - a male.
216
00:23:43,801 --> 00:23:48,186
You might not think that it's the most colourful you've ever seen
217
00:23:48,211 --> 00:23:53,216
but, with our ultraviolet camera, his wings take on a magical look.
218
00:23:59,361 --> 00:24:01,056
The brighter his patches,
219
00:24:01,081 --> 00:24:03,165
the more attractive he is to females.
220
00:24:08,601 --> 00:24:11,295
But ultraviolet markings like these can also
221
00:24:11,320 --> 00:24:14,056
be seen by the blue moon's main predators.
222
00:24:17,190 --> 00:24:19,936
Birds can see them just as clearly.
223
00:24:24,031 --> 00:24:28,056
So flying around with a bright signal like that on your wings
224
00:24:28,081 --> 00:24:29,086
could be dangerous.
225
00:24:35,640 --> 00:24:39,826
For a male, however, it's worth living dangerously.
226
00:24:39,851 --> 00:24:43,726
If he can mate with one or two females in his short lifetime,
227
00:24:43,751 --> 00:24:45,726
his colours will have been a success.
228
00:24:53,961 --> 00:24:55,656
But he has competition.
229
00:24:57,601 --> 00:25:01,576
He will have to defend his territory if he is to secure a mate.
230
00:25:05,111 --> 00:25:08,976
Butterfly wings are fragile, so physical combat is to be avoided.
231
00:25:12,241 --> 00:25:16,295
Disputes instead are settled with aerial displays.
232
00:25:33,981 --> 00:25:36,026
Time to show her his colours.
233
00:25:55,051 --> 00:25:58,156
In her eyes, he's simply dazzling.
234
00:26:13,941 --> 00:26:18,876
Ultraviolet colours are part of the spectrum that insects can see...
235
00:26:18,901 --> 00:26:20,236
...and we cannot.
236
00:26:22,951 --> 00:26:26,565
Recent discoveries have revealed that some animals can also
237
00:26:26,590 --> 00:26:30,156
see a characteristic of light that we cannot detect.
238
00:26:32,491 --> 00:26:37,315
Sunlight contains rays that vibrate in many different planes.
239
00:26:38,701 --> 00:26:42,315
In polarised light, they vibrate in only one.
240
00:26:44,181 --> 00:26:46,716
Light may become polarised
241
00:26:46,741 --> 00:26:49,716
when reflected off a shiny surface, such as water.
242
00:26:51,460 --> 00:26:55,996
Unlike us, some animals can see polarised light,
243
00:26:56,021 --> 00:26:58,826
and they can exploit it in many ways.
244
00:27:03,901 --> 00:27:05,826
One creature that does so
245
00:27:05,851 --> 00:27:09,996
lives on these vast mudflats in northern Australia.
246
00:27:15,460 --> 00:27:19,996
These eyes - on stalks - belong to a male fiddler crab.
247
00:27:23,021 --> 00:27:25,796
And they can see in a way that we cannot.
248
00:27:34,101 --> 00:27:37,956
As the tide goes out, the crabs emerge from their burrows.
249
00:27:46,340 --> 00:27:50,466
His giant claw is too large to be used in feeding.
250
00:27:53,540 --> 00:27:57,596
Instead, he uses it to attract the attention of females...
251
00:27:57,621 --> 00:27:59,746
...by waving it with vigour!
252
00:28:02,901 --> 00:28:06,596
The crabs can see objects that are close to them reasonably well...
253
00:28:09,621 --> 00:28:13,185
...but their long-distance eyesight is not so good.
254
00:28:18,181 --> 00:28:21,515
Polarised light can help solve the problem.
255
00:28:26,210 --> 00:28:29,596
Viewed with a new specialist camera, the mudflats,
256
00:28:29,621 --> 00:28:32,826
which reflect polarised light, are bright...
257
00:28:35,851 --> 00:28:40,565
...while the unpolarised crabs appear darker against their background.
258
00:28:42,410 --> 00:28:46,635
This striking contrast also makes the large claw more obvious.
259
00:28:49,691 --> 00:28:53,916
The big claw is also used by the male to defend his burrow.
260
00:28:58,821 --> 00:29:01,026
Not everyone heeds the warning.
261
00:29:15,771 --> 00:29:16,796
Battle over.
262
00:29:20,021 --> 00:29:23,236
But there are more dangerous enemies to face -
263
00:29:23,261 --> 00:29:24,565
aerial predators.
264
00:29:26,131 --> 00:29:29,385
The quicker they can spot them, the better
265
00:29:29,410 --> 00:29:33,276
and, once again, polarised light helps them to do so.
266
00:29:46,981 --> 00:29:51,156
With the coast clear, a male re-emerges from his burrow.
267
00:29:55,051 --> 00:29:56,876
At last, a female.
268
00:30:03,901 --> 00:30:07,876
With the tide on the turn, he must work fast to win her over.
269
00:30:15,021 --> 00:30:17,746
And close up, his colours come into play.
270
00:30:19,301 --> 00:30:23,356
The brightness of his blue back could be the deciding factor.
271
00:30:32,691 --> 00:30:34,596
She may not look willing,
272
00:30:34,621 --> 00:30:38,466
but the pushing and shoving are all part of the mating ritual.
273
00:30:43,410 --> 00:30:46,276
One last shove and she's in...
274
00:30:49,491 --> 00:30:50,656
...just in time.
275
00:31:05,101 --> 00:31:09,276
On land, colour is used in a multitude of different ways.
276
00:31:10,460 --> 00:31:13,596
The same is true in the sea, but there,
277
00:31:13,621 --> 00:31:16,236
colour works in a very different way.
278
00:31:26,590 --> 00:31:29,635
This is Australia's Great Barrier Reef,
279
00:31:29,660 --> 00:31:33,236
and its shallow waters are full of vivid colour.
280
00:31:39,491 --> 00:31:43,185
The inhabitants of the reef exploit it to the full,
281
00:31:43,210 --> 00:31:45,916
with unparalleled and dazzling effect.
282
00:32:02,691 --> 00:32:06,466
The orange-red stripes of the harlequin tuskfish
283
00:32:06,491 --> 00:32:07,996
make it very conspicuous.
284
00:32:12,181 --> 00:32:14,466
But as light filters down through the water,
285
00:32:14,491 --> 00:32:17,515
more and more of its wavelengths are absorbed...
286
00:32:19,051 --> 00:32:21,486
...and red is the first to disappear.
287
00:32:23,901 --> 00:32:27,026
So, as the harlequin swims downwards,
288
00:32:27,051 --> 00:32:30,876
his brilliantly coloured red body looks duller and duller.
289
00:32:42,381 --> 00:32:47,315
Different colours are absorbed at different rates in the sea,
290
00:32:47,340 --> 00:32:50,106
but some can still be seen at greater depths.
291
00:32:53,981 --> 00:32:56,385
Yellow and blue travel farthest,
292
00:32:56,410 --> 00:33:00,996
so it's these that many fish down here use to signal their identity.
293
00:33:07,301 --> 00:33:10,716
Most fish near the surface have good colour vision,
294
00:33:10,741 --> 00:33:15,206
but some of the smaller species can also see ultraviolet colours.
295
00:33:19,181 --> 00:33:22,876
To us, these yellow damselfish all look very similar.
296
00:33:27,901 --> 00:33:32,876
But using our ultraviolet camera here in controlled conditions,
297
00:33:32,901 --> 00:33:36,156
we can see that many fish have different patterns
298
00:33:36,181 --> 00:33:38,996
that are normally invisible to our eyes.
299
00:33:42,301 --> 00:33:44,565
And suddenly, it becomes clear that
300
00:33:44,590 --> 00:33:48,565
these two individuals are in fact different species.
301
00:33:52,641 --> 00:33:56,096
This lemon damselfish has distinctive spots
302
00:33:56,121 --> 00:33:57,335
on its gill covers.
303
00:34:00,001 --> 00:34:03,296
And this, an Ambon damsel,
304
00:34:03,321 --> 00:34:08,256
has bright reflecting ultraviolet patches all across the body.
305
00:34:10,961 --> 00:34:13,335
It's a code invisible to us
306
00:34:13,360 --> 00:34:16,016
that allows these fish to recognise each other...
307
00:34:18,641 --> 00:34:21,766
...without attracting the attention of large predators,
308
00:34:21,791 --> 00:34:24,616
which can't see in the ultraviolet range.
309
00:34:32,711 --> 00:34:35,405
And it's on the seabed that you can find
310
00:34:35,430 --> 00:34:38,046
one of the most colourful sea creatures of all...
311
00:34:44,610 --> 00:34:47,126
...the peacock mantis shrimp.
312
00:34:53,360 --> 00:34:56,096
This strange-looking creature's ancestry
313
00:34:56,121 --> 00:34:59,046
can be traced back 400 million years...
314
00:35:01,430 --> 00:35:05,046
...and it has one of the most versatile kinds of eyes in the whole
315
00:35:05,071 --> 00:35:06,616
of the animal kingdom.
316
00:35:11,891 --> 00:35:16,896
It can rotate its two huge eyes independently of each other
317
00:35:16,921 --> 00:35:18,446
and in almost any direction.
318
00:35:21,211 --> 00:35:25,216
We have three kinds of colour receptors, but the mantis shrimp
319
00:35:25,241 --> 00:35:29,086
has 12, each with a direct link to the brain,
320
00:35:29,111 --> 00:35:32,896
so it can perceive colour faster than any other animal.
321
00:35:35,031 --> 00:35:38,726
And it can also detect the difference between polarised
322
00:35:38,751 --> 00:35:40,056
and unpolarised light.
323
00:35:44,440 --> 00:35:47,615
But unlike fiddler crabs, part of its body,
324
00:35:47,640 --> 00:35:51,826
like these paddle-shaped scales, reflect polarised light...
325
00:35:53,161 --> 00:35:56,285
...and may be used to signal to potential mates.
326
00:36:03,310 --> 00:36:07,726
The tail is also highly polarised and used to plug its burrow
327
00:36:07,751 --> 00:36:11,165
and send a message to warn off potential rivals.
328
00:36:17,361 --> 00:36:20,615
And by combining all its visual abilities,
329
00:36:20,640 --> 00:36:25,256
the mantis shrimp has become one of the most skilful of all predators.
330
00:36:37,640 --> 00:36:42,056
It also packs a powerful punch from club-like mouth parts...
331
00:36:45,921 --> 00:36:48,336
...which it uses with great accuracy.
332
00:36:51,161 --> 00:36:55,415
These clubs deliver the fastest punch in the animal kingdom,
333
00:36:55,440 --> 00:36:59,535
which we recorded slowed down and under controlled conditions.
334
00:37:12,721 --> 00:37:18,136
Whether underwater or on land, colour can be extremely useful.
335
00:37:23,081 --> 00:37:26,446
And the colours an animal develops can sometimes be
336
00:37:26,471 --> 00:37:30,216
influenced by where it lives and what it eats.
337
00:37:39,241 --> 00:37:42,256
The Atacama Desert in South America.
338
00:37:54,001 --> 00:37:57,896
There are six different species of flamingos in the world,
339
00:37:57,921 --> 00:38:01,285
and they all prefer to breed in those most
340
00:38:01,310 --> 00:38:05,576
hostile of environments - salt flats and soda lakes.
341
00:38:11,211 --> 00:38:15,345
We think of flamingos as being characteristically pink,
342
00:38:15,370 --> 00:38:19,086
but their feathers when they first appear are in fact white.
343
00:38:23,520 --> 00:38:26,006
Their colour comes from their food.
344
00:38:29,601 --> 00:38:33,896
The salty waters in which they feed are rich in algae and shrimps,
345
00:38:33,921 --> 00:38:38,086
both of which contain red pigments called carotenoids.
346
00:38:41,310 --> 00:38:44,535
These, over time, accumulate in their feathers and give them
347
00:38:44,560 --> 00:38:45,646
their bright colour.
348
00:39:02,921 --> 00:39:06,086
These youngsters were born last year.
349
00:39:06,111 --> 00:39:08,936
They still have their first greyish-white plumage.
350
00:39:15,721 --> 00:39:18,615
It takes time before the pigments become visible.
351
00:39:24,751 --> 00:39:29,365
Five years will pass before they become as pink as their parents.
352
00:39:38,361 --> 00:39:41,535
But it's not only the juveniles which are white.
353
00:39:47,161 --> 00:39:50,696
This adult female raised a chick last year,
354
00:39:50,721 --> 00:39:54,256
and the effort of doing so has drained her of colour.
355
00:39:57,471 --> 00:40:01,415
She put all her surplus food and energy into producing an egg
356
00:40:01,440 --> 00:40:03,285
and then feeding her chick.
357
00:40:05,721 --> 00:40:09,576
So she will need time to build up the body reserves needed to
358
00:40:09,601 --> 00:40:12,336
regrow pink feathers and breed.
359
00:40:20,560 --> 00:40:23,936
For those that are old enough and physically fit,
360
00:40:23,961 --> 00:40:25,726
it's time to find a mate.
361
00:40:29,640 --> 00:40:32,856
Only the pink birds take part in these courtship dances.
362
00:40:37,361 --> 00:40:41,285
Their colour is an indication that they're fit and strong.
363
00:41:00,801 --> 00:41:03,006
As they march through the water,
364
00:41:03,031 --> 00:41:06,086
each bird tries to stand out from the crowd...
365
00:41:07,161 --> 00:41:10,806
...and the brightest will be the first to secure a partner.
366
00:41:17,881 --> 00:41:22,336
The white female can play no part in this year's display.
367
00:41:29,361 --> 00:41:31,726
She will need to eat as much as she can
368
00:41:31,751 --> 00:41:33,856
if she is to restore her colour.
369
00:41:37,361 --> 00:41:41,776
Maybe next year she will be able to rejoin the dance.
370
00:41:53,851 --> 00:41:57,696
Flamingos depend on their pink colour to attract a partner
371
00:41:57,721 --> 00:41:58,726
and breed.
372
00:42:01,801 --> 00:42:05,896
But there is one tiny animal in the Central American rainforests
373
00:42:05,921 --> 00:42:08,086
that uses colour not only
374
00:42:08,111 --> 00:42:10,336
to attract, but to repel.
375
00:42:20,881 --> 00:42:24,056
This little frog uses colour as a warning.
376
00:42:25,211 --> 00:42:27,446
Its skin is full of glands
377
00:42:27,471 --> 00:42:30,285
which produce a deadly poison,
378
00:42:30,310 --> 00:42:31,415
so its colour is
379
00:42:31,440 --> 00:42:32,976
a VGFY CIGBF ITIGSSBQG -
380
00:42:33,001 --> 00:42:35,256
eat me and you'll regret it!
381
00:42:39,001 --> 00:42:43,555
You need a vivid message like this if you are a small,
382
00:42:43,580 --> 00:42:48,956
soft-skinned, bite-sized mouthful living in a dark, dense forest.
383
00:43:02,051 --> 00:43:04,996
The rainforest can be a scary place.
384
00:43:09,741 --> 00:43:12,356
There are hungry animals everywhere.
385
00:43:27,410 --> 00:43:30,916
For many, it's best to keep a low profile.
386
00:43:35,491 --> 00:43:37,666
But this little frog doesn't.
387
00:43:39,540 --> 00:43:42,796
It's a strawberry poison-dart frog,
388
00:43:42,821 --> 00:43:45,466
and it's not much bigger than your fingernail...
389
00:43:46,491 --> 00:43:49,515
...and yet he is one of the deadliest creatures here.
390
00:43:52,540 --> 00:43:55,106
His bright skin secretes a toxin.
391
00:43:57,491 --> 00:44:01,515
In the mouth of a predator, it can cause respiratory failure,
392
00:44:01,540 --> 00:44:03,666
convulsions and death.
393
00:44:07,491 --> 00:44:12,076
Predators recognise his colour as a sign of danger and avoid him.
394
00:44:18,941 --> 00:44:23,156
Such frogs also live on a group of islands just off Panama
395
00:44:23,181 --> 00:44:25,305
called Bocas del Toro.
396
00:44:27,660 --> 00:44:29,106
Living in isolation,
397
00:44:29,131 --> 00:44:33,196
frogs on each island evolved their own distinctive colours.
398
00:44:36,381 --> 00:44:39,076
There is a different one on each island.
399
00:44:42,691 --> 00:44:45,236
And yet they're all the same species.
400
00:44:51,410 --> 00:44:55,515
They're different because the diet on some islands makes some
401
00:44:55,540 --> 00:44:57,916
more poisonous than others.
402
00:44:57,941 --> 00:45:02,156
And the more poison a frog has, the more brightly coloured it is.
403
00:45:11,261 --> 00:45:15,515
On Solarte Island, a red male is busy calling.
404
00:45:15,540 --> 00:45:23,515
HE CROAKS
405
00:45:25,021 --> 00:45:28,876
This is his patch, and he's looking for a female.
406
00:45:32,410 --> 00:45:33,946
He should be popular.
407
00:45:33,971 --> 00:45:38,196
Females prefer bright, shiny skin, which is a sign of fitness.
408
00:45:43,051 --> 00:45:47,276
His colour is also an indication to other males of his strength.
409
00:45:56,621 --> 00:45:58,076
He spots an intruder.
410
00:45:59,181 --> 00:46:02,716
He's about the same size, but he's a paler colour.
411
00:46:12,580 --> 00:46:15,555
And he doesn't challenge the brighter frog.
412
00:46:22,051 --> 00:46:24,515
But this one is a different matter.
413
00:46:27,580 --> 00:46:29,106
He is a contender.
414
00:46:40,540 --> 00:46:43,276
Nothing for it but to fight it out.
415
00:47:25,301 --> 00:47:28,716
That did it - he won't be back for a while.
416
00:47:37,051 --> 00:47:38,946
And the reward...
417
00:47:38,971 --> 00:47:39,996
...a new mate.
418
00:47:46,691 --> 00:47:51,305
For these tiny frogs, colour is central to all aspects of their
419
00:47:51,330 --> 00:47:57,196
lives - for protection, to dominate rivals and to find a partner.
420
00:47:58,741 --> 00:48:01,746
For them, life is colour.
421
00:48:11,941 --> 00:48:15,276
When I started working in television in the 1950s,
422
00:48:15,301 --> 00:48:19,356
all broadcasts were in black and white, and conveying animal
423
00:48:19,381 --> 00:48:23,996
colour took a leap of the imagination on the viewer's part.
424
00:48:24,021 --> 00:48:27,276
Well, those are only some of the birds of paradise we brought back,
425
00:48:27,301 --> 00:48:29,666
and there's one more I'd like to show you -
426
00:48:29,691 --> 00:48:32,236
the king bird of paradise.
427
00:48:32,261 --> 00:48:35,635
Its feathers are brilliant red, except for its white underparts.
428
00:48:38,330 --> 00:48:42,196
When colour TV arrived almost 20 years later, we were suddenly
429
00:48:42,221 --> 00:48:45,916
able to show some of the wonderful colours of the natural world.
430
00:48:52,381 --> 00:48:56,385
Since then, electronic cameras have made extraordinary technical
431
00:48:56,410 --> 00:49:01,305
advances into high definition and even ultra-high definition.
432
00:49:03,021 --> 00:49:06,466
But we've always known that there's another world of colour -
433
00:49:06,491 --> 00:49:09,385
one that only some animals can see.
434
00:49:13,901 --> 00:49:17,635
In these programmes, new camera technology has provided
435
00:49:17,660 --> 00:49:21,076
a window into these hitherto invisible worlds...
436
00:49:24,851 --> 00:49:28,356
...and one of these is that revealed by polarised light.
437
00:49:31,101 --> 00:49:34,635
It plays a crucial role in the lives of many animals,
438
00:49:34,660 --> 00:49:38,716
including these small fiddler crabs in Darwin, Australia.
439
00:49:44,101 --> 00:49:47,876
We worked with a team of scientists to develop a unique
440
00:49:47,901 --> 00:49:52,596
and pioneering camera system to reveal this hidden world.
441
00:49:52,621 --> 00:49:53,996
100% here.
442
00:49:55,301 --> 00:49:58,635
The camera detects areas of polarisation,
443
00:49:58,660 --> 00:50:02,276
such as the light that passes through polarising sunglasses.
444
00:50:02,301 --> 00:50:04,796
Put it to 100% here.
445
00:50:04,821 --> 00:50:08,515
It then combines vertical and horizontal polarisation
446
00:50:08,540 --> 00:50:12,746
to show the contrast between polarised and unpolarised light.
447
00:50:14,901 --> 00:50:19,196
With this new camera, the team hope to find out how fiddler crabs
448
00:50:19,221 --> 00:50:22,156
use polarised light to signal to each other.
449
00:50:24,460 --> 00:50:27,666
But this camera had been developed in sterile, controlled
450
00:50:27,691 --> 00:50:31,716
conditions, and these fiddler crabs live in one of the least sterile
451
00:50:31,741 --> 00:50:35,716
environments on Earth - Australia's tropical mudflats.
452
00:50:38,491 --> 00:50:42,305
Quite a challenge for the cameraman, Mark Lamble.
453
00:50:42,330 --> 00:50:46,435
That mudflat - it's just a really extreme environment to work.
454
00:50:46,460 --> 00:50:51,666
Blazing sun overhead, really high humidity and almost no airflow.
455
00:50:55,181 --> 00:50:56,716
The camera needed to be
456
00:50:56,741 --> 00:51:00,876
half-buried in mud to get a fiddler crab's eye view.
457
00:51:02,580 --> 00:51:05,596
Whether the camera would work here, no-one could be sure.
458
00:51:07,131 --> 00:51:08,826
I'm slightly worried.
459
00:51:08,851 --> 00:51:11,635
Hopefully, we are not going to miss that special moment
460
00:51:11,660 --> 00:51:15,185
as the camera is not going to work, but I think we'll be OK.
461
00:51:15,210 --> 00:51:16,796
Good luck.
Thank you.
462
00:51:19,901 --> 00:51:23,356
Once in position, Mark settled down for an uncomfortable wait.
463
00:51:27,381 --> 00:51:30,716
If the crabs detect the slightest movement,
464
00:51:30,741 --> 00:51:32,946
they disappear into their burrows...
465
00:51:35,460 --> 00:51:36,466
...again...
466
00:51:38,261 --> 00:51:39,276
...and again.
467
00:51:41,971 --> 00:51:45,515
I have to be really still or they will not come out at all.
468
00:51:46,621 --> 00:51:48,515
I'd love to be able to have an umbrella over me,
469
00:51:48,540 --> 00:51:50,555
so anything higher than me
470
00:51:50,580 --> 00:51:55,635
is just not tolerated by the fiddler crabs, they just won't come up.
471
00:51:55,660 --> 00:52:00,276
But amazingly, the camera survived the heat, the humidity
472
00:52:00,301 --> 00:52:04,635
and the caustic brine, and eventually Mark was able to capture,
473
00:52:04,660 --> 00:52:08,946
for the first time, a fiddler crab's world in polarised light.
474
00:52:12,410 --> 00:52:16,555
Light reflected from the crabs' bodies is unpolarised,
475
00:52:16,580 --> 00:52:17,596
so they look dark.
476
00:52:19,051 --> 00:52:21,796
This makes them stand out against the mudflats,
477
00:52:21,821 --> 00:52:24,435
from which the reflected light is polarised.
478
00:52:26,741 --> 00:52:30,106
They can see things that we can only imagine.
479
00:52:30,131 --> 00:52:33,515
When you look up and you see a bird fly over, it's a white bird against
480
00:52:33,540 --> 00:52:37,836
a white sky whereas, when they look up, it's just this total silhouette
481
00:52:37,861 --> 00:52:42,555
with the polarisation, and they can see birds coming from miles away,
482
00:52:42,580 --> 00:52:46,026
and often I'm filming and they'll all bolt down their holes,
483
00:52:46,051 --> 00:52:47,746
and I'll wonder why they've done it,
484
00:52:47,771 --> 00:52:49,356
and it's just because they've spotted
485
00:52:49,381 --> 00:52:52,026
a bird way earlier than I would have been able to see it.
486
00:52:54,971 --> 00:52:58,635
So polarised light helps the crabs pick out distant potential
487
00:52:58,660 --> 00:53:03,026
mates, rivals and predators more quickly against their bright,
488
00:53:03,051 --> 00:53:06,716
polarised background. And for Victor,
489
00:53:06,741 --> 00:53:09,996
it was the first time he had seen the camera he had developed in
490
00:53:10,021 --> 00:53:15,486
the lab revealing the world in the way these tiny creatures see it.
491
00:53:15,511 --> 00:53:18,996
It's amazing footage you've captured, Mark. It's really amazing.
492
00:53:20,580 --> 00:53:23,586
You really put the system to its limits today.
493
00:53:27,410 --> 00:53:31,156
But there was one even bigger challenge for the camera -
494
00:53:31,181 --> 00:53:33,635
one that lay farther out to sea.
495
00:53:36,851 --> 00:53:40,515
Underwater, only crustaceans, cephalopods
496
00:53:40,540 --> 00:53:45,435
and a few fish are known to be able to see and react to polarised light.
497
00:53:46,691 --> 00:53:49,796
But there is one animal here that exploits this ability
498
00:53:49,821 --> 00:53:55,515
in a really complex way - the peacock mantis shrimp.
499
00:53:55,540 --> 00:53:59,435
It's not only able to detect polarisation, but has patches
500
00:53:59,460 --> 00:54:03,836
on its body that reflect light in a polarised form,
501
00:54:03,861 --> 00:54:07,321
and it uses them to signal to others of their own kind
502
00:54:07,346 --> 00:54:09,811
in ways that we cannot normally see.
503
00:54:12,086 --> 00:54:15,341
Professorjustin Marshall of Queensland University has
504
00:54:15,366 --> 00:54:19,500
adapted the polarising camera to work underwater.
505
00:54:19,525 --> 00:54:20,731
So here we go, Rory.
506
00:54:20,756 --> 00:54:25,261
This is the camera that's going to show us polarisation.
507
00:54:25,286 --> 00:54:28,290
Rory McGuinness, the team's underwater cameraman,
508
00:54:28,315 --> 00:54:31,141
arrives to see the latest version of the camera.
509
00:54:32,806 --> 00:54:35,011
So you've obviously done a lot of work to get
510
00:54:35,036 --> 00:54:36,861
this into an underwater housing?
511
00:54:36,886 --> 00:54:38,011
Yep, that's right.
512
00:54:38,036 --> 00:54:41,821
So you can see in here there's a computer that runs the camera.
513
00:54:41,846 --> 00:54:44,451
There's quite a lot of engineering going on in there.
514
00:54:50,395 --> 00:54:55,341
Taking the camera for its first test underwater was a tense moment.
515
00:54:55,366 --> 00:54:58,731
Computers and salt water don't usually mix well.
516
00:55:07,366 --> 00:55:09,290
Having found a suitable spot,
517
00:55:09,315 --> 00:55:12,420
it was time for the camera's first critical test.
518
00:55:17,395 --> 00:55:19,420
A leak could be disastrous...
519
00:55:23,806 --> 00:55:25,571
...but all is well.
520
00:55:25,596 --> 00:55:27,861
Now they need a mantis shrimp.
521
00:55:27,886 --> 00:55:31,011
Looks like a promising area, Justin.
522
00:55:31,036 --> 00:55:32,731
It looks perfect, Rory.
523
00:55:32,756 --> 00:55:37,141
So we're looking for a hole with coral around it.
524
00:55:40,006 --> 00:55:44,370
Hey, look! ls that a mantis shrimp hole?
525
00:55:44,395 --> 00:55:46,901
The hole's resident soon appeared.
526
00:55:46,926 --> 00:55:49,500
It was time for the camera to show what it could do.
527
00:55:51,395 --> 00:55:55,471
As the shrimp turns, the polarised camera shows that its tail
528
00:55:55,496 --> 00:55:59,651
has a shimmering fringe - invisible in normal light.
529
00:55:59,676 --> 00:56:02,981
Look at that.
That's extraordinary!
530
00:56:03,006 --> 00:56:04,901
Life in polarised light.
531
00:56:06,315 --> 00:56:08,061
And this is the first time...
532
00:56:10,596 --> 00:56:14,571
...we've been able to do this with this very special camera.
533
00:56:16,645 --> 00:56:20,370
The light on the ocean floor is unpolarised.
534
00:56:20,395 --> 00:56:23,420
So, in complete reverse to the fiddler crabs,
535
00:56:23,445 --> 00:56:26,620
the mantis shrimps use polarisation to stand out
536
00:56:26,645 --> 00:56:29,091
against the unpolarised background.
537
00:56:33,496 --> 00:56:38,821
Special pigments polarise the light reflected from parts of their body,
538
00:56:38,846 --> 00:56:43,341
allowing them to signal to deter intruders and attract mates.
539
00:56:48,846 --> 00:56:53,540
This camera has revealed to us a first glimpse into a world of light
540
00:56:53,565 --> 00:56:57,091
that we're only beginning to be aware of, let alone understand.
541
00:57:06,036 --> 00:57:09,620
In the next episode, the story of Life In Colour
542
00:57:09,645 --> 00:57:12,981
continues where the stakes are even higher
543
00:57:13,006 --> 00:57:15,451
and colour is the key to survival.
544
00:57:17,395 --> 00:57:22,061
We discover how animals use colour to hide from predators
545
00:57:22,086 --> 00:57:23,981
and from their prey.
45916
Can't find what you're looking for?
Get subtitles in any language from opensubtitles.com, and translate them here.