1
00:00:23,648 --> 00:00:26,276
There's something
magical about dolphins.
2
00:00:30,947 --> 00:00:32,866
They appear so friendly.
3
00:00:35,410 --> 00:00:37,162
Yet so otherworldly.
4
00:00:41,207 --> 00:00:43,251
They're clearly intelligent.
5
00:00:46,713 --> 00:00:47,797
And agile.
6
00:00:56,765 --> 00:01:00,643
But we've still barely glimpsed
beneath the surface.
7
00:01:05,940 --> 00:01:08,818
Now we can immerse ourselves
in their world,
8
00:01:09,486 --> 00:01:12,655
we're discovering
just how sophisticated they are.
9
00:01:21,414 --> 00:01:23,041
And the deeper we look,
10
00:01:24,292 --> 00:01:25,835
the more like us they seem.
11
00:01:52,695 --> 00:01:56,116
Born into a world
where he can't even breathe,
12
00:01:57,784 --> 00:01:59,744
a young Atlantic spotted dolphin
13
00:01:59,828 --> 00:02:02,747
has a lot to learn about surviving at sea.
14
00:02:06,835 --> 00:02:09,712
A good thing he has someone
to show him the way.
15
00:02:13,883 --> 00:02:14,717
Mom.
16
00:02:19,514 --> 00:02:22,642
And a wider group of family and friends.
17
00:02:38,992 --> 00:02:40,869
They'll help teach him
18
00:02:41,661 --> 00:02:43,163
how to find food…
19
00:02:45,248 --> 00:02:47,792
and how to avoid danger.
20
00:02:54,257 --> 00:02:56,634
But dolphin society is complicated.
21
00:02:58,094 --> 00:02:59,762
The greatest challenge
22
00:02:59,846 --> 00:03:01,973
is learning how to fit in.
23
00:03:15,028 --> 00:03:17,322
These warm, shallow waters
24
00:03:17,405 --> 00:03:19,866
are also home to another species.
25
00:03:21,784 --> 00:03:23,578
Bottlenose dolphins.
26
00:03:31,211 --> 00:03:35,465
This might seem the perfect place
for a mother to raise her newborn calf…
27
00:03:37,592 --> 00:03:38,551
but even here,
28
00:03:39,260 --> 00:03:41,054
life isn't easy.
29
00:03:49,354 --> 00:03:50,980
They're being followed.
30
00:03:55,735 --> 00:03:57,153
A group of males,
31
00:03:58,071 --> 00:03:59,572
looking for a mate.
32
00:04:02,784 --> 00:04:05,620
They could attack the baby to get to Mom.
33
00:04:17,966 --> 00:04:20,134
More dolphins join the chase.
34
00:04:28,351 --> 00:04:31,271
Mom does all she can to protect her calf.
35
00:04:39,195 --> 00:04:40,280
Eventually,
36
00:04:40,905 --> 00:04:42,282
she fights them off.
37
00:04:45,660 --> 00:04:47,704
But her baby is nowhere to be seen.
38
00:04:58,006 --> 00:05:01,134
Alone, he stands little chance.
39
00:05:25,908 --> 00:05:28,328
Reunited with Mom…
40
00:05:30,496 --> 00:05:32,040
and her allies,
41
00:05:33,416 --> 00:05:37,503
the calf a little wiser
in the ways of the world.
42
00:05:39,088 --> 00:05:43,676
But his lessons in becoming a dolphin
have only just begun.
43
00:05:57,857 --> 00:06:01,235
Dolphins are air-breathing mammals,
like us.
44
00:06:03,946 --> 00:06:07,033
Their ancestors once lived on dry land,
45
00:06:08,659 --> 00:06:10,912
but 50 million years ago,
46
00:06:10,995 --> 00:06:13,122
they did something amazing.
47
00:06:14,832 --> 00:06:16,125
Left the land
48
00:06:16,209 --> 00:06:19,253
to enter a life aquatic.
49
00:06:24,133 --> 00:06:25,802
While one branch of the family
50
00:06:25,885 --> 00:06:29,514
became huge, filter-feeding baleen whales…
51
00:06:31,933 --> 00:06:34,685
they turned into streamlined,
52
00:06:34,769 --> 00:06:36,896
quick-thinking predators.
53
00:06:39,774 --> 00:06:44,445
Today, over 40 species of dolphin
hunt the oceans of the world.
54
00:06:50,034 --> 00:06:51,953
From tropical waters…
55
00:06:55,915 --> 00:06:57,834
to polar seas,
56
00:06:59,419 --> 00:07:03,548
and even in rivers
thousands of miles inland,
57
00:07:05,466 --> 00:07:07,260
wherever there is prey,
58
00:07:08,386 --> 00:07:11,806
there's a dolphin
with a clever way of catching it.
59
00:07:21,441 --> 00:07:24,902
Orca are the largest members
of the family.
60
00:07:27,155 --> 00:07:29,824
They can grow nearly 30 feet long
61
00:07:30,366 --> 00:07:33,119
and weigh seven tons.
62
00:07:37,790 --> 00:07:41,461
Each needs to catch
over 100 lb. of food a day.
63
00:07:43,713 --> 00:07:45,798
Not easy in the polar winter.
64
00:07:46,924 --> 00:07:49,218
Unless you know where to look.
65
00:08:02,690 --> 00:08:04,609
During the coldest months,
66
00:08:04,692 --> 00:08:07,945
their favorite prey
shelters in protected fjords.
67
00:08:13,743 --> 00:08:14,660
Herring.
68
00:08:15,995 --> 00:08:19,081
In their billions.
69
00:08:31,344 --> 00:08:33,930
Tracking down their exact location
70
00:08:34,013 --> 00:08:35,181
can be tricky.
71
00:08:39,560 --> 00:08:41,521
Catching them is even harder.
72
00:08:50,988 --> 00:08:53,282
Led by an experienced female,
73
00:08:54,408 --> 00:08:58,621
the family pod home in on the vast shoal.
74
00:09:02,250 --> 00:09:04,544
As long as the herring keep formation,
75
00:09:05,920 --> 00:09:07,713
they're hard to single out.
76
00:09:18,891 --> 00:09:20,768
But the orca have a plan.
77
00:09:24,063 --> 00:09:26,274
With pulsing calls,
78
00:09:27,233 --> 00:09:29,485
and by flashing their white bellies…
79
00:09:32,405 --> 00:09:35,366
they herd the herring into the shallows.
80
00:09:50,464 --> 00:09:54,302
In the panic, the fish form
tighter and tighter shoals.
81
00:10:04,353 --> 00:10:05,980
Until finally,
82
00:10:06,063 --> 00:10:08,608
the orca can strike.
83
00:10:19,785 --> 00:10:24,123
Smashing their tail flukes
creates powerful pressure waves.
84
00:10:29,170 --> 00:10:31,756
A barrage of knockout blows.
85
00:10:39,555 --> 00:10:41,432
Once the fish are stunned,
86
00:10:42,224 --> 00:10:44,977
the orca can eat at leisure.
87
00:11:09,043 --> 00:11:13,297
Dolphins maximize their hunting success
by working as a team.
88
00:11:15,216 --> 00:11:17,134
And out in the open ocean,
89
00:11:17,218 --> 00:11:19,512
they operate on an epic scale.
90
00:11:25,059 --> 00:11:28,229
A stampede of spinner dolphins.
91
00:11:30,523 --> 00:11:34,193
A super pod over a thousand strong.
92
00:11:51,085 --> 00:11:54,046
They make such an effective hunting force,
93
00:11:54,755 --> 00:11:57,842
they can afford plenty of downtime.
94
00:12:11,605 --> 00:12:13,441
Two hundred miles east of Brazil,
95
00:12:14,608 --> 00:12:17,153
this archipelago is a favorite stop-off
96
00:12:17,236 --> 00:12:19,196
for Atlantic spinner dolphins.
97
00:12:22,908 --> 00:12:25,369
They head for the island's shallow bays.
98
00:12:28,581 --> 00:12:32,418
The first arrivals are in high spirits.
99
00:12:47,933 --> 00:12:51,061
The Olympic gymnasts
of the dolphin family.
100
00:12:52,396 --> 00:12:55,357
They can leap ten feet
101
00:12:56,233 --> 00:12:58,277
and spin seven times.
102
00:13:11,123 --> 00:13:12,750
It looks a lot of fun.
103
00:13:15,044 --> 00:13:18,214
But it's thought
there's more to these acrobatics.
104
00:13:26,096 --> 00:13:28,182
Perhaps they're communicating,
105
00:13:28,265 --> 00:13:30,768
greeting other dolphins entering the bay.
106
00:13:45,825 --> 00:13:47,618
With safety in numbers,
107
00:13:48,452 --> 00:13:50,621
the spinners can relax.
108
00:14:02,466 --> 00:14:04,677
But they can't switch off completely,
109
00:14:05,427 --> 00:14:07,012
or they would drown.
110
00:14:08,389 --> 00:14:11,767
So they shut down
one side of their brain at a time…
111
00:14:13,853 --> 00:14:16,272
with one eye on where they're going.
112
00:14:18,190 --> 00:14:20,818
Sleep swimming at half speed.
113
00:14:27,616 --> 00:14:29,994
While older dolphins rest,
114
00:14:31,370 --> 00:14:33,998
the younger ones play.
115
00:14:56,478 --> 00:14:58,480
A game of seaweed catch.
116
00:15:28,218 --> 00:15:30,387
It seems simple enough.
117
00:15:33,807 --> 00:15:37,353
But this is
surprisingly sophisticated play.
118
00:15:39,563 --> 00:15:41,649
Manipulating objects,
119
00:15:43,025 --> 00:15:46,111
copying moves and, most importantly,
120
00:15:46,195 --> 00:15:47,780
understanding each other.
121
00:15:48,864 --> 00:15:54,453
A skill every young dolphin
must master as it grows.
122
00:16:00,334 --> 00:16:02,211
By a year old,
123
00:16:02,294 --> 00:16:06,674
an Atlantic spotted calf
is almost fluent in dolphin.
124
00:16:22,189 --> 00:16:25,609
Much can be communicated
through body language and touch.
125
00:16:27,695 --> 00:16:29,780
A flipper rub reassures,
126
00:16:30,781 --> 00:16:32,282
like holding hands.
127
00:16:35,369 --> 00:16:39,373
But some things
can only be said with sound.
128
00:16:42,960 --> 00:16:44,962
His mom repeats a unique call.
129
00:16:48,799 --> 00:16:50,300
Her signature whistle.
130
00:16:53,429 --> 00:16:55,764
It helps him to find her in a crowd.
131
00:17:00,602 --> 00:17:02,896
And once he's learned to copy it,
132
00:17:02,980 --> 00:17:04,857
he can call her by her name.
133
00:17:08,027 --> 00:17:11,572
Now it's time to experiment
with a whistle of his own.
134
00:17:16,452 --> 00:17:17,745
Like children,
135
00:17:17,828 --> 00:17:20,664
dolphins take years learning to speak.
136
00:17:23,125 --> 00:17:25,085
And once they start talking…
137
00:17:28,255 --> 00:17:30,841
…they never let up.
138
00:17:38,223 --> 00:17:42,186
But a dolphin's sonic skills
go way beyond words.
139
00:17:48,108 --> 00:17:51,904
The local bottlenose
are searching for food on the sea floor.
140
00:17:54,073 --> 00:17:56,033
There doesn't appear to be much here.
141
00:17:57,826 --> 00:18:01,997
But they can see things we can't.
142
00:18:09,338 --> 00:18:12,424
They fire a stream of high-pitched clicks.
143
00:18:13,634 --> 00:18:16,595
Five hundred per second.
144
00:18:24,645 --> 00:18:26,647
And interpret the echoes
145
00:18:26,730 --> 00:18:29,566
to pinpoint fish hiding in the sand.
146
00:18:52,381 --> 00:18:55,801
Echolocation is
an extraordinary sixth sense…
147
00:18:57,845 --> 00:19:03,142
that allows dolphins to hunt
in the most unlikely of places.
148
00:19:15,112 --> 00:19:16,405
A muddy estuary,
149
00:19:17,447 --> 00:19:20,033
and the tide is dropping.
150
00:19:21,702 --> 00:19:25,956
Right now, heading inland
could be a risky move.
151
00:19:38,677 --> 00:19:43,265
But this dolphin knows
the estuary is full of fish.
152
00:19:53,901 --> 00:19:55,903
Using echolocation,
153
00:19:55,986 --> 00:20:00,616
she can navigate the silty waters
and find her prey.
154
00:20:08,665 --> 00:20:10,250
Only problem is,
155
00:20:10,334 --> 00:20:13,295
at low tide they hide in the oyster beds.
156
00:20:15,214 --> 00:20:18,300
Charging in would shred
her sensitive skin.
157
00:20:20,761 --> 00:20:25,098
Somehow, she needs
to get the fish into the open.
158
00:20:38,820 --> 00:20:42,741
Pumping her tail,
she flushes them out of hiding
159
00:20:43,825 --> 00:20:47,246
and towards the sandy banks,
where it's safe to strike.
160
00:20:55,712 --> 00:20:58,840
Only a few dolphins
have learned to hunt like this.
161
00:21:03,679 --> 00:21:05,764
And the technique only works
162
00:21:05,847 --> 00:21:08,058
for a few hours each day.
163
00:21:14,731 --> 00:21:17,317
When the tide begins to rise,
164
00:21:17,401 --> 00:21:19,319
the fish disperse.
165
00:21:22,698 --> 00:21:24,616
A new strategy is needed.
166
00:21:28,662 --> 00:21:30,664
She joins forces with friends
167
00:21:31,999 --> 00:21:35,460
and together they head
towards wider channels.
168
00:21:39,506 --> 00:21:40,507
Then,
169
00:21:42,384 --> 00:21:43,593
they wait.
170
00:22:28,013 --> 00:22:30,223
Each time a shoal swims past,
171
00:22:30,307 --> 00:22:32,184
the dolphins attack,
172
00:22:33,852 --> 00:22:36,980
creating bow waves
that wash the fish ashore.
173
00:22:54,581 --> 00:22:58,335
Through echolocation and coordination,
174
00:22:58,418 --> 00:23:01,505
they conjure a feast from the mud.
175
00:23:08,261 --> 00:23:10,263
Out in the big blue,
176
00:23:10,347 --> 00:23:13,767
dolphins must push
their super senses to the limits.
177
00:23:21,108 --> 00:23:22,984
The challenge of hunting in the abyss
178
00:23:23,068 --> 00:23:27,781
has created one of the most
extraordinary dolphins of all.
179
00:23:48,468 --> 00:23:51,054
Pilot whales may look strange,
180
00:23:51,763 --> 00:23:55,892
but their bulbous foreheads
hold the secret to their success.
181
00:23:57,144 --> 00:24:01,231
They project long-range sonic beams
hundreds of feet.
182
00:24:02,274 --> 00:24:05,777
The most powerful echolocation
of any dolphin.
183
00:24:13,702 --> 00:24:16,830
It enables pilot whales
to hunt shoals of squid
184
00:24:16,913 --> 00:24:19,040
over half a mile down.
185
00:24:29,426 --> 00:24:33,138
But young calves can't hold their breath
long enough to follow.
186
00:24:37,517 --> 00:24:40,645
So the family take turns
187
00:24:40,729 --> 00:24:42,689
babysitting at the surface.
188
00:24:45,942 --> 00:24:48,653
Grandma is over 50 years old.
189
00:24:49,988 --> 00:24:53,325
But she still produces milk
to keep the youngsters fed.
190
00:25:02,417 --> 00:25:05,879
These dolphins live up to 70 years
191
00:25:06,880 --> 00:25:09,174
and stay with the family for life.
192
00:25:10,050 --> 00:25:14,971
Possibly the longest,
most loyal bonds of any animal.
193
00:25:22,437 --> 00:25:24,606
When the hunting party surfaces,
194
00:25:24,689 --> 00:25:26,691
it's clear they've had success.
195
00:25:32,781 --> 00:25:34,366
Time to move on.
196
00:25:35,742 --> 00:25:38,870
Grandma has a mental map
of their ocean home.
197
00:25:39,996 --> 00:25:43,792
She listens for the sounds
of waves crashing on islands
198
00:25:43,875 --> 00:25:46,545
and currents washing around sea mouths.
199
00:25:49,548 --> 00:25:52,342
Acoustic landmarks revealing the route.
200
00:25:59,349 --> 00:26:00,559
But sometimes,
201
00:26:01,810 --> 00:26:04,312
even these great navigators
lose their way.
202
00:26:09,776 --> 00:26:10,652
Every year,
203
00:26:11,653 --> 00:26:15,282
hundreds of dolphins
strand on beaches around the world.
204
00:26:16,241 --> 00:26:18,785
Pilot whales more often than most.
205
00:26:20,954 --> 00:26:23,915
It only takes one or two to go off course…
206
00:26:26,001 --> 00:26:29,546
and family members
feel compelled to swim to their side.
207
00:26:33,133 --> 00:26:36,261
Sometimes, their distress calls
bring hundreds more.
208
00:26:44,436 --> 00:26:46,354
Natural disasters,
209
00:26:46,438 --> 00:26:48,815
noise pollution, and ill health
210
00:26:48,898 --> 00:26:51,067
all seem to play a part.
211
00:26:53,570 --> 00:26:57,198
But the exact triggers for these events
are poorly understood.
212
00:27:04,623 --> 00:27:08,126
People do all they can
to keep stranded whales alive
213
00:27:08,209 --> 00:27:10,920
and try to help them back out to sea.
214
00:27:20,430 --> 00:27:23,975
The connection between humans
and dolphins runs deep.
215
00:27:25,685 --> 00:27:30,106
We share a thrill-seeking side
found in few other animals.
216
00:27:31,232 --> 00:27:36,237
And we express ourselves in ways
that have no obvious role in survival.
217
00:27:41,034 --> 00:27:43,828
But it seems
there's purpose to all this play.
218
00:27:46,289 --> 00:27:48,667
It produces a rush of hormones
219
00:27:48,750 --> 00:27:51,920
that create feelings
of confidence and joy.
220
00:27:53,630 --> 00:27:56,883
Playing together heightens these emotions…
221
00:27:59,052 --> 00:28:03,014
encouraging teamwork
and time spent with friends.
222
00:28:17,070 --> 00:28:20,365
Perhaps this is why dolphins
seek the company of others.
223
00:28:34,754 --> 00:28:36,881
Playing with their own kind.
224
00:28:41,720 --> 00:28:42,554
With us.
225
00:28:46,558 --> 00:28:48,560
And with other animals.
226
00:29:15,336 --> 00:29:18,256
Dolphins are famous
for their friendly nature.
227
00:29:20,425 --> 00:29:22,844
But they also have a darker side.
228
00:29:36,608 --> 00:29:39,944
When the ocean's top predators go hunting,
229
00:29:40,028 --> 00:29:42,071
nothing is safe.
230
00:30:01,591 --> 00:30:04,177
Southern right whales.
231
00:30:06,304 --> 00:30:08,556
Up to 80 tons.
232
00:30:10,058 --> 00:30:12,852
Ten times heavier than an orca.
233
00:30:21,319 --> 00:30:23,112
But working as a team,
234
00:30:24,072 --> 00:30:26,741
orca are almost unstoppable.
235
00:30:32,038 --> 00:30:34,457
The right whales make for the shallows
236
00:30:34,541 --> 00:30:36,543
to avoid attack from below.
237
00:30:40,880 --> 00:30:43,758
But orca don't give up easily.
238
00:30:48,012 --> 00:30:49,848
Taking turns,
239
00:30:49,931 --> 00:30:52,851
they smash into the whales' flanks,
240
00:30:52,934 --> 00:30:54,644
hitting them where it hurts.
241
00:31:05,029 --> 00:31:07,073
The whales strike back.
242
00:31:35,018 --> 00:31:39,147
But it's only when the sounds of struggle
attract more right whales
243
00:31:40,690 --> 00:31:43,693
that the orca finally back off.
244
00:31:50,533 --> 00:31:53,286
Orca's ability to take on such large prey
245
00:31:53,369 --> 00:31:55,914
earned them the nickname "whale killers,"
246
00:31:56,581 --> 00:31:57,415
or
247
00:31:58,166 --> 00:31:59,375
"killer whales."
248
00:32:02,879 --> 00:32:05,298
Dolphins are not just ruthless hunters.
249
00:32:06,591 --> 00:32:10,178
They can also be
surprisingly aggressive to each other.
250
00:32:24,359 --> 00:32:25,610
By six years old,
251
00:32:26,194 --> 00:32:28,154
this young spotted dolphin
252
00:32:28,237 --> 00:32:31,366
has finally developed his trademark spots.
253
00:32:37,330 --> 00:32:38,998
He's seeing less of Mom…
254
00:32:41,042 --> 00:32:44,253
and spending more time
hanging out with friends.
255
00:32:48,841 --> 00:32:52,512
Building alliances is crucial
in these early years.
256
00:33:02,730 --> 00:33:06,567
Dolphins form more numerous,
more intense relationships
257
00:33:06,651 --> 00:33:09,821
than any other animal except us.
258
00:33:14,951 --> 00:33:18,162
As he matures,
life will become more complicated.
259
00:33:22,083 --> 00:33:24,585
And he'll need all the friends he can get.
260
00:33:36,723 --> 00:33:40,309
A community of bottlenose dolphins
in Western Australia
261
00:33:40,393 --> 00:33:45,314
is considered the most sophisticated
dolphin society of all.
262
00:33:48,276 --> 00:33:50,945
Two thousand live in this one bay.
263
00:34:02,081 --> 00:34:04,208
During the breeding season,
264
00:34:04,292 --> 00:34:07,670
who you know
becomes more important than ever.
265
00:34:09,714 --> 00:34:11,632
Males that are able to team up
266
00:34:11,716 --> 00:34:13,968
have more chance of winning a mate.
267
00:34:28,316 --> 00:34:31,194
This trio hangs out
on the east side of the bay.
268
00:34:37,492 --> 00:34:41,496
They've been best friends for 20 years.
269
00:34:44,791 --> 00:34:49,253
Swimming in sync
shows just how tight they are.
270
00:34:51,714 --> 00:34:55,802
And choreographed moves
help impress the opposite sex.
271
00:35:02,892 --> 00:35:04,602
There's the crossover.
272
00:35:07,230 --> 00:35:08,439
The butterfly.
273
00:35:12,068 --> 00:35:13,903
The duo tail touch.
274
00:35:16,114 --> 00:35:17,949
Synchronous dives.
275
00:35:20,118 --> 00:35:21,494
Dual leaps.
276
00:35:22,954 --> 00:35:24,539
Tango moves.
277
00:35:25,206 --> 00:35:29,001
And the inverse rooster strut.
278
00:35:32,213 --> 00:35:35,967
The slicker the routine,
the more attractive they seem.
279
00:35:41,514 --> 00:35:42,765
Even so,
280
00:35:42,849 --> 00:35:45,518
it often takes days to win over a female.
281
00:35:51,649 --> 00:35:54,360
And now they have competition.
282
00:35:56,487 --> 00:35:57,864
On the west side,
283
00:35:57,947 --> 00:36:00,074
rival gangs are forming.
284
00:36:03,369 --> 00:36:05,663
The east side trio needs backup.
285
00:36:08,958 --> 00:36:11,752
So they call on a wider circle of friends.
286
00:36:31,397 --> 00:36:33,191
Weaker gangs usually back down.
287
00:36:35,568 --> 00:36:37,945
But when the sides are equally matched,
288
00:36:39,322 --> 00:36:41,782
fights can cause serious injury.
289
00:37:30,039 --> 00:37:31,040
An hour later,
290
00:37:32,124 --> 00:37:33,334
it's all over.
291
00:37:38,256 --> 00:37:41,550
Through strong allegiances
and tight teamwork,
292
00:37:41,634 --> 00:37:44,178
the east side friends emerge victorious
293
00:37:44,804 --> 00:37:48,599
and win the chance
to father the next generation.
294
00:37:52,770 --> 00:37:54,897
Intelligence and collaboration
295
00:37:54,981 --> 00:37:58,943
have enabled dolphins
to navigate life in the ocean.
296
00:38:01,362 --> 00:38:03,781
But their home is changing fast.
297
00:38:08,577 --> 00:38:12,248
Even these adaptable animals
are struggling to cope.
298
00:38:18,587 --> 00:38:20,673
Our seas are becoming noisier.
299
00:38:22,800 --> 00:38:23,676
Warmer.
300
00:38:25,428 --> 00:38:26,804
And more polluted.
301
00:38:34,270 --> 00:38:35,896
Instead of seaweed,
302
00:38:35,980 --> 00:38:39,108
many dolphins now play with plastic bags.
303
00:38:49,618 --> 00:38:55,291
Swallowing trash kills over
100,000 marine mammals every year.
304
00:38:56,334 --> 00:38:58,586
And chemical contamination
305
00:38:58,669 --> 00:39:01,339
threatens their ability to reproduce.
306
00:39:04,675 --> 00:39:09,305
But industrial-scale fishing
is the biggest problem dolphins face…
307
00:39:11,974 --> 00:39:14,393
rapidly depleting their vital food
308
00:39:15,019 --> 00:39:19,190
and drowning hundreds
of thousands of them each year.
309
00:39:28,240 --> 00:39:31,369
However, even small changes in our actions
310
00:39:31,452 --> 00:39:33,704
can make a big difference.
311
00:39:47,385 --> 00:39:49,303
When fishermen trawl for shrimp…
312
00:39:52,056 --> 00:39:54,558
other animals are caught in their nets.
313
00:39:57,061 --> 00:40:00,564
But these fishermen
now incorporate special openings
314
00:40:00,648 --> 00:40:02,858
so larger animals can escape.
315
00:40:06,153 --> 00:40:09,365
And the local bottlenose
have learned to seek them out,
316
00:40:10,825 --> 00:40:14,745
using the exit holes
to pick out a prize of fish.
317
00:40:31,429 --> 00:40:34,598
Entering these death traps
is a risky maneuver.
318
00:40:38,769 --> 00:40:41,689
But these hungry dolphins
take their chances.
319
00:40:56,495 --> 00:40:58,289
And the fishermen tolerate them.
320
00:41:01,208 --> 00:41:03,043
There's no loss to their catch.
321
00:41:08,466 --> 00:41:11,218
We still have a lot to learn
about dolphins.
322
00:41:12,011 --> 00:41:15,389
And while some species
are on the brink of extinction,
323
00:41:17,057 --> 00:41:20,311
new ones are still being found.
324
00:41:26,650 --> 00:41:31,906
It's long been thought there were five
species of river dolphin in the world.
325
00:41:31,989 --> 00:41:35,242
Now biologists believe
they've discovered a sixth.
326
00:41:37,328 --> 00:41:42,500
Only around 1,000 Araguaian river dolphins
are thought to exist.
327
00:41:46,253 --> 00:41:48,005
But every day
328
00:41:48,088 --> 00:41:50,341
in this Brazilian town,
329
00:41:50,424 --> 00:41:52,760
a small number come to hang out.
330
00:41:54,887 --> 00:41:58,432
The local children can hardly wait.
331
00:42:03,687 --> 00:42:08,108
It's easy to understand
their affinity with these magical animals.
332
00:42:12,696 --> 00:42:16,992
Humans and dolphins
may inhabit very different worlds…
333
00:42:19,495 --> 00:42:22,998
but there's much in our nature
that we share.
334
00:42:30,089 --> 00:42:32,800
A deep connection to be cherished
335
00:42:33,676 --> 00:42:36,470
for generations to come.