1
00:00:03,000 --> 00:00:05,720
A young whale
born late in the season

2
00:00:05,720 --> 00:00:08,280
faces an urgent race against time.

3
00:00:13,120 --> 00:00:15,520
And things are about to get rough.

4
00:00:19,320 --> 00:00:22,680
Male giants dangerously vie
for supremacy.

5
00:00:26,640 --> 00:00:28,880
Hunters sweep in for the kill.

6
00:00:36,920 --> 00:00:42,320
The allure of southern waters
offers a feast for the taking.

7
00:00:42,320 --> 00:00:45,560
But only the strongest
can endure the epic journey.

8
00:00:47,640 --> 00:00:50,200
Can the young calf overcome the odds

9
00:00:50,200 --> 00:00:53,040
to make one of the greatest
migrations on Earth?

10
00:00:53,040 --> 00:00:55,760
The race is on.

11
00:01:26,440 --> 00:01:30,040
In crystal clear waters
off the west coast of Colombia...

12
00:01:33,400 --> 00:01:37,240
..a young humpback whale
draws his first breath.

13
00:01:40,120 --> 00:01:44,320
His mother gently lifts
her precious newborn to the surface.

14
00:01:47,640 --> 00:01:50,400
The cool air
triggers a deep instinct.

15
00:01:53,680 --> 00:01:56,520
For the first time,
he fills his lungs.

16
00:01:58,720 --> 00:02:02,640
Each breath, a conscious decision
to come to the surface.

17
00:02:08,840 --> 00:02:11,680
He must quickly master
this vital act.

18
00:02:19,560 --> 00:02:22,920
For now, his colossal mother
guides him up for air.

19
00:02:25,040 --> 00:02:29,200
The first lesson in the life
of every humpback whale.

20
00:02:38,720 --> 00:02:43,200
He's been born to a vast,
dark and salty world -

21
00:02:43,200 --> 00:02:47,200
the eastern tropical Pacific,
off the coast of Colombia.

22
00:02:52,600 --> 00:02:55,440
It's an intimidating place
for the little male,

23
00:02:55,440 --> 00:02:57,080
but he won't have to go it alone.

24
00:03:00,600 --> 00:03:02,560
For the first year of his life,

25
00:03:02,560 --> 00:03:05,320
his mother will never stray
from his side.

26
00:03:10,720 --> 00:03:14,920
Add 16ft long,
he's already a third of her length.

27
00:03:14,920 --> 00:03:17,120
Despite her vast size,

28
00:03:17,120 --> 00:03:20,440
he spent the final stages
of pregnancy folded over

29
00:03:20,440 --> 00:03:22,120
to fit in her womb.

30
00:03:23,240 --> 00:03:26,720
It takes time to straighten out
and strengthen his muscles.

31
00:03:32,480 --> 00:03:35,920
He must master his huge tail,
flukes and flippers.

32
00:03:40,040 --> 00:03:43,920
Not the easiest of tasks for a calf
born without the thick,

33
00:03:43,920 --> 00:03:47,200
buoyant layer of blubber
that would keep him afloat.

34
00:03:53,720 --> 00:03:58,160
Until this layer builds up,
the calf could sink and drown.

35
00:04:01,560 --> 00:04:05,840
But his mother has already invested
11 months in his pregnancy,

36
00:04:05,840 --> 00:04:07,960
so she's not about
to let that happen.

37
00:04:13,400 --> 00:04:19,040
She's over 50ft long
and tips the scales at 90,000 lbs.

38
00:04:19,040 --> 00:04:22,680
Her mass alone rivals
a small herd of elephants.

39
00:04:26,160 --> 00:04:28,960
He's got some serious
catching up to do.

40
00:04:30,200 --> 00:04:32,040
It will take him 12 to 15 years

41
00:04:32,040 --> 00:04:35,080
to become one of the greatest giants
on the planet.

42
00:04:42,400 --> 00:04:44,840
To boost his piling on the pounds,

43
00:04:44,840 --> 00:04:48,400
he has some of the world's richest
milk on tap.

44
00:04:52,040 --> 00:04:55,120
His mother's teats are close
to the base of her tail,

45
00:04:55,120 --> 00:04:56,240
so to reach them,

46
00:04:56,240 --> 00:04:59,840
he must hold his breath
and dive under.

47
00:04:59,840 --> 00:05:03,760
As he nuzzles her underside,
her nipple protrudes and squirts

48
00:05:03,760 --> 00:05:05,160
milk into his mouth.

49
00:05:08,320 --> 00:05:12,560
Day or night, he'll spend
about 30% of his time feeding.

50
00:05:14,840 --> 00:05:17,320
To begin with, feeding
is a laborious affair

51
00:05:17,320 --> 00:05:19,160
for the baby whale.

52
00:05:19,160 --> 00:05:22,240
He can only hold his breath
for a few minutes.

53
00:05:22,240 --> 00:05:25,160
After a quick sip, he must paddle
back to the surface for air.

54
00:05:32,640 --> 00:05:35,560
Recharged,
he returns to the milk bar.

55
00:05:40,960 --> 00:05:43,920
He'll drink
more than 43 gallons a day.

56
00:05:45,520 --> 00:05:47,760
His mother's milk is 50% fat,

57
00:05:47,760 --> 00:05:51,920
fuelling growth that is almost
visible to the naked eye.

58
00:05:54,680 --> 00:05:58,760
Baby humpbacks typically grow
at a rate of more than four inches

59
00:05:58,760 --> 00:06:01,880
a week,
but this male is not typical.

60
00:06:03,800 --> 00:06:07,080
Most calves here are born
in early July.

61
00:06:07,080 --> 00:06:08,720
It's now almost August.

62
00:06:10,320 --> 00:06:12,800
He's been born a few weeks late.

63
00:06:14,800 --> 00:06:17,760
It's a setback
that could cost him dearly.

64
00:06:19,880 --> 00:06:22,640
In November, he will undergo
one of the longest migrations

65
00:06:22,640 --> 00:06:26,880
on the planet - south,
to the frigid waters of Antarctica.

66
00:06:28,680 --> 00:06:32,600
If he doesn't bulk up in time
and grow strong, he will never

67
00:06:32,600 --> 00:06:34,880
survive the 5,000-mile journey.

68
00:06:37,760 --> 00:06:40,320
This is where his mother
fuelled her pregnancy.

69
00:06:42,040 --> 00:06:46,640
Southern summers bring long hours
of sunlight to the poles.

70
00:06:46,640 --> 00:06:50,880
Algal blooms flourish
in the abundant light, resulting

71
00:06:50,880 --> 00:06:53,960
in an explosion
of tiny shrimp called krill.

72
00:06:55,720 --> 00:07:00,520
These two-inch-long crustaceans form
the basis of the humpback menu.

73
00:07:08,840 --> 00:07:13,440
With gaping jaws, the whales engulf
giant mouthfuls of the shrimp.

74
00:07:16,440 --> 00:07:20,720
One large mouthful takes in
5,000 gallons of sea water...

75
00:07:20,720 --> 00:07:23,040
..and everything swimming in it.

76
00:07:24,600 --> 00:07:27,440
The water escapes
through the baleen plates

77
00:07:27,440 --> 00:07:31,400
in their upper jaws - giant sieves
trapping the food within.

78
00:07:36,360 --> 00:07:39,520
It's a feast
that's five months long.

79
00:07:39,520 --> 00:07:42,680
Each humpback gorges
on one-and-a-half tonnes of food

80
00:07:42,680 --> 00:07:44,200
each day.

81
00:07:46,960 --> 00:07:51,520
By season's end, they've gained
several tonnes of blubber, enough

82
00:07:51,520 --> 00:07:56,240
to sustain them as they head away
from the frigid waters of Antarctica

83
00:07:56,240 --> 00:07:57,680
and turn north.

84
00:08:05,440 --> 00:08:09,080
Before winter arrives,
they must return to the warm waters

85
00:08:09,080 --> 00:08:11,400
of Colombia, where they'll breed.

86
00:08:14,080 --> 00:08:18,040
It's a monster journey,
taking six to 12 weeks,

87
00:08:18,040 --> 00:08:20,800
covering 5,300 miles.

88
00:08:22,920 --> 00:08:27,560
In June, around 1,000 whales
descend on this patch of ocean

89
00:08:27,560 --> 00:08:29,400
off the coast of Colombia.

90
00:08:30,760 --> 00:08:34,840
The calf's mother was born
in this same area.

91
00:08:34,840 --> 00:08:38,440
She returns here
every two to three years to breed.

92
00:08:42,040 --> 00:08:46,600
Her newborn calf is small enough
to be vulnerable to large sharks

93
00:08:46,600 --> 00:08:51,760
and killer whales, so she's selected
a very special nursery.

94
00:08:51,760 --> 00:08:57,560
22 miles off Colombia's Pacific
coast is the island of Gorgona.

95
00:08:57,560 --> 00:09:00,120
A sheltered bay
on its east coast acts

96
00:09:00,120 --> 00:09:02,880
as a birthing ground
for humpback whales.

97
00:09:05,480 --> 00:09:10,440
Gorgona towers over 1,000ft
above the Pacific, thrown up

98
00:09:10,440 --> 00:09:14,000
by volcanic activity
some 90 million years ago,

99
00:09:14,000 --> 00:09:16,360
during the age of the dinosaurs.

100
00:09:19,480 --> 00:09:22,360
The island is far older than whales
themselves,

101
00:09:22,360 --> 00:09:24,720
which first appeared
in the oceans

102
00:09:24,720 --> 00:09:26,680
around 50 million years ago.

103
00:09:28,160 --> 00:09:31,920
It's entirely possible that whales
have been visiting Gorgona's

104
00:09:31,920 --> 00:09:33,560
waters ever since.

105
00:09:36,480 --> 00:09:39,160
Thanks to its proximity
to the equator,

106
00:09:39,160 --> 00:09:43,440
its waters remain 23
to 27 degrees centigrade year-round,

107
00:09:43,440 --> 00:09:46,400
providing a warm welcome
for the whales

108
00:09:46,400 --> 00:09:49,560
and ideal nursery conditions
for their young.

109
00:09:51,200 --> 00:09:55,200
The depth of the water in
Gorgona's sheltered bay is perfect

110
00:09:55,200 --> 00:09:58,200
for protecting young calves.

111
00:09:58,200 --> 00:10:03,200
At just 65ft deep, it's harder
for predators to sneak in and launch

112
00:10:03,200 --> 00:10:04,480
a surprise attack.

113
00:10:08,320 --> 00:10:11,520
Gorgona's waters attract
other ocean migrants -

114
00:10:11,520 --> 00:10:14,200
olive ridley and green sea turtles.

115
00:10:15,800 --> 00:10:18,240
Like the humpbacks, they travel

116
00:10:18,240 --> 00:10:22,120
over thousands of miles
of ocean every year.

117
00:10:22,120 --> 00:10:27,200
Genetic studies show that the green
sea turtles come from birthing sites

118
00:10:27,200 --> 00:10:31,520
on the Galapagos Islands,
more than 800 miles away.

119
00:10:31,520 --> 00:10:35,920
There are even some that have made
the 5,500 mile journey from Hawaii.

120
00:10:40,360 --> 00:10:42,800
Baby green turtles are drifters,

121
00:10:42,800 --> 00:10:45,440
disappearing into the open seas

122
00:10:45,440 --> 00:10:49,320
and riding the currents
until they're about ten years old.

123
00:10:49,320 --> 00:10:53,320
Then, as teenagers, some arrive
on the reef off Gorgona and stay

124
00:10:53,320 --> 00:10:54,320
here to feed.

125
00:10:58,080 --> 00:11:01,720
Most of the green sea turtles
won't breed here. They'll fatten

126
00:11:01,720 --> 00:11:06,160
up for a decade or so before
returning to where they were born.

127
00:11:07,200 --> 00:11:09,680
Young green turtles are carnivores,

128
00:11:09,680 --> 00:11:13,120
but as they mature,
they switch to a vegetarian diet.

129
00:11:16,680 --> 00:11:20,120
This adult female is eating algae.

130
00:11:20,120 --> 00:11:22,840
She's one of the few green turtles
that were born here.

131
00:11:27,680 --> 00:11:30,200
At 3ft long, she is fully mature

132
00:11:30,200 --> 00:11:34,360
and, unlike most of the other
greens, she is here to breed.

133
00:11:35,720 --> 00:11:37,360
She has recently mated.

134
00:11:39,840 --> 00:11:44,920
It takes about 15 days for the eggs
to develop inside her.

135
00:11:44,920 --> 00:11:48,640
While she waits, she must eat
as much as she can to ensure

136
00:11:48,640 --> 00:11:52,160
her developing clutch
gets the nutrition it needs.

137
00:12:02,000 --> 00:12:05,280
She's not the only one
fattening up in the bay.

138
00:12:07,560 --> 00:12:10,440
The young male calf is doing well.

139
00:12:10,440 --> 00:12:13,880
After a couple of weeks
of piling on the pounds, his body

140
00:12:13,880 --> 00:12:14,920
has filled out.

141
00:12:17,040 --> 00:12:20,840
But as he gets bigger,
he's faced with a new problem.

142
00:12:24,800 --> 00:12:28,960
It takes a while for whale calves
to master their buoyancy.

143
00:12:32,880 --> 00:12:36,880
He seems to flounder back and forth
towards the surface.

144
00:12:36,880 --> 00:12:39,800
WHALE CALLS

145
00:12:39,800 --> 00:12:44,680
His mother, hovering nearby,
is neutrally buoyant and can hang

146
00:12:44,680 --> 00:12:46,880
motionless for hours at a time.

147
00:12:48,480 --> 00:12:51,120
Every time the calf tries
to hover like his mother,

148
00:12:51,120 --> 00:12:52,560
he drifts and rolls.

149
00:12:57,960 --> 00:13:01,200
The only hope of getting
a much-needed rest is to wedge

150
00:13:01,200 --> 00:13:03,480
himself under his mother's chin.

151
00:13:06,800 --> 00:13:10,080
Like all baby animals,
he needs a lot of sleep.

152
00:13:11,280 --> 00:13:15,600
Thanks to his mother's hydrodynamic
design, he can nap any time

153
00:13:15,600 --> 00:13:16,920
without losing her.

154
00:13:18,080 --> 00:13:20,960
As long as he stays close
to her, he's gently pulled

155
00:13:20,960 --> 00:13:22,640
along in her slipstream.

156
00:13:24,120 --> 00:13:26,080
It's known as echelon swimming,

157
00:13:26,080 --> 00:13:29,240
and it means his mother does
all the heavy lifting

158
00:13:29,240 --> 00:13:32,080
while he conserves
his energy for growing.

159
00:13:33,160 --> 00:13:36,520
He now has only three months
until he must take the mammoth

160
00:13:36,520 --> 00:13:38,080
journey to Antarctica.

161
00:13:39,600 --> 00:13:43,800
It's crucial the baby's big enough
and has enough blubber

162
00:13:43,800 --> 00:13:45,280
to survive the trip.

163
00:13:45,280 --> 00:13:49,160
To ensure every calorie goes
into his growth, his mother does

164
00:13:49,160 --> 00:13:51,360
everything she can to prevent him

165
00:13:51,360 --> 00:13:55,000
from expending
any unnecessary energy.

166
00:13:55,000 --> 00:13:58,840
Normally, mothers and calves
spend half their time resting,

167
00:13:58,840 --> 00:14:03,720
but unwanted visitors to the island
make that a near impossible task.

168
00:14:05,640 --> 00:14:07,280
Adult male humpbacks...

169
00:14:08,720 --> 00:14:11,320
..with only one thing
on their minds -

170
00:14:11,320 --> 00:14:12,520
finding a mate.

171
00:14:15,680 --> 00:14:20,120
By August, the waters off Gorgona
are teeming with whales.

172
00:14:20,120 --> 00:14:23,000
Up to 1,000 gather here every year.

173
00:14:26,440 --> 00:14:29,160
Male humpbacks aren't as big
as the females,

174
00:14:29,160 --> 00:14:32,600
but at around 45ft,
they're still huge.

175
00:14:32,600 --> 00:14:36,320
And they are determined
to throw their weight around.

176
00:14:36,320 --> 00:14:38,520
With immensely powerful tails,

177
00:14:38,520 --> 00:14:41,720
they're able to hurl
their 30-tonne bodies into the air.

178
00:14:48,320 --> 00:14:50,720
Whales breach for various reasons.

179
00:14:53,800 --> 00:14:58,560
But on the breeding ground, male
breaching reaches its peak as rivals

180
00:14:58,560 --> 00:15:02,280
try to outcompete each other
and impress the females.

181
00:15:20,680 --> 00:15:24,240
WHALE SONG

182
00:15:27,560 --> 00:15:29,800
But they also have a gentler way

183
00:15:29,800 --> 00:15:33,000
to get themselves noticed
while they're here.

184
00:15:36,400 --> 00:15:41,160
Humpbacks sing the longest,
loudest songs on Earth.

185
00:15:41,160 --> 00:15:43,480
It's an exclusively male pursuit,

186
00:15:43,480 --> 00:15:48,120
and incredibly, they manage
to create sound without vocal cords.

187
00:15:49,320 --> 00:15:53,560
Instead, the whales use special
folds in their larynx which vibrate,

188
00:15:53,560 --> 00:15:56,600
creating sound as air
is pushed through them.

189
00:15:57,920 --> 00:16:01,480
The notes are so powerful,
they can be heard thousands of miles

190
00:16:01,480 --> 00:16:04,760
away, echoing across
entire ocean basins.

191
00:16:06,920 --> 00:16:11,840
WHALE SONG

192
00:16:11,840 --> 00:16:16,360
These epic songs last around
16 minutes and repeat on a loop

193
00:16:16,360 --> 00:16:18,720
for up to 23 hours at a time.

194
00:16:20,840 --> 00:16:25,680
Each new breeding season heralds
a new song, specific to a region,

195
00:16:25,680 --> 00:16:29,560
and every male in that population
sings that same tune.

196
00:16:32,440 --> 00:16:35,000
Every year, it evolves and changes.

197
00:16:36,960 --> 00:16:39,880
Who composes it
and how they all learn it is,

198
00:16:39,880 --> 00:16:42,960
like so much of the whales' lives,
a mystery.

199
00:16:52,680 --> 00:16:56,480
The latest research suggests
that the whales learn the songs

200
00:16:56,480 --> 00:16:57,760
one phrase at a time,

201
00:16:57,760 --> 00:17:00,760
in much the same way
that a human gradually learns

202
00:17:00,760 --> 00:17:01,800
a new language.

203
00:17:05,840 --> 00:17:09,760
It was long assumed that the purpose
of whale music was only

204
00:17:09,760 --> 00:17:11,040
to attract a mate.

205
00:17:15,720 --> 00:17:19,120
But scientists, using the same
methods that have been used

206
00:17:19,120 --> 00:17:22,520
to analyse bird songs,
have discovered that whales use

207
00:17:22,520 --> 00:17:25,600
different musical phrases
for different purposes,

208
00:17:25,600 --> 00:17:29,240
not only for mating,
but also to identify themselves.

209
00:17:34,400 --> 00:17:36,600
When one male approaches another,

210
00:17:36,600 --> 00:17:39,720
they sing the individual phrases
faster.

211
00:17:42,960 --> 00:17:46,520
It's thought that by engaging
in a sing-off, humpbacks

212
00:17:46,520 --> 00:17:50,520
can determine which individuals
are the strongest rivals.

213
00:17:54,480 --> 00:17:58,840
What is known is that one singer
quickly attracts other males.

214
00:18:00,880 --> 00:18:05,200
The males form rowdy gangs
that patrol the breeding grounds,

215
00:18:05,200 --> 00:18:07,200
looking for available mates.

216
00:18:11,360 --> 00:18:16,000
Females typically breed again only
once their calf is at least a year

217
00:18:16,000 --> 00:18:19,640
old, but that doesn't stop the males
from moving in on the mother

218
00:18:19,640 --> 00:18:22,720
with her newborn calf.

219
00:18:22,720 --> 00:18:25,720
He's barely a month old
and still totally dependent on her.

220
00:18:28,000 --> 00:18:30,560
The largest of the males approaches.

221
00:18:37,000 --> 00:18:40,640
Like all male humpbacks,
he is smaller than the female,

222
00:18:40,640 --> 00:18:43,880
but his behaviour
is nonetheless intimidating.

223
00:18:45,320 --> 00:18:47,920
It's extremely stressful
for the mother and her calf.

224
00:18:49,960 --> 00:18:54,920
Mothers and calves harassed by males
must expend a lot of energy,

225
00:18:54,920 --> 00:18:59,520
energy the calf should be using
to grow and build fat reserves.

226
00:19:01,560 --> 00:19:06,000
But worse, in trying to get close
to what he sees as a potential mate,

227
00:19:06,000 --> 00:19:09,080
the adult male risks crushing
the tiny calf.

228
00:19:11,320 --> 00:19:15,520
His mother tries to guide him safely
out of harm's way, but her potential

229
00:19:15,520 --> 00:19:17,640
suitors don't get the message.

230
00:19:21,680 --> 00:19:23,960
The males become more boisterous,

231
00:19:23,960 --> 00:19:26,480
hurling themselves out of the water,

232
00:19:26,480 --> 00:19:29,280
demonstrating
their incredible strength.

233
00:19:43,040 --> 00:19:47,680
The calf wouldn't survive the impact
of a 65,000lb male

234
00:19:47,680 --> 00:19:50,320
crashing down on him.

235
00:19:50,320 --> 00:19:53,920
Desperate to keep her calf away
from the raucous males, the mother

236
00:19:53,920 --> 00:19:56,840
is faced with a difficult choice -

237
00:19:56,840 --> 00:20:01,200
move her calf further offshore, away
from the safety of the bay's shallow

238
00:20:01,200 --> 00:20:05,960
waters, or stay close
to the coast and risk the males

239
00:20:05,960 --> 00:20:07,240
injuring her baby.

240
00:20:10,320 --> 00:20:13,120
Reluctantly,
she moves further offshore.

241
00:20:16,720 --> 00:20:20,000
The frantic encounter
has taken its toll, depleting

242
00:20:20,000 --> 00:20:22,120
the calf's limited resources.

243
00:20:23,680 --> 00:20:26,560
Stressed and exhausted,
he desperately clings

244
00:20:26,560 --> 00:20:28,040
to his mother's side.

245
00:20:31,080 --> 00:20:33,960
The calf is now adrift
in 900ft of water.

246
00:20:35,680 --> 00:20:38,320
This is far from ideal.

247
00:20:38,320 --> 00:20:42,360
They may be away
from testosterone-fuelled males,

248
00:20:42,360 --> 00:20:43,520
but out here,

249
00:20:43,520 --> 00:20:45,760
the potential for predation
is far greater.

250
00:20:53,120 --> 00:20:58,360
The biggest threat to any young
humpback patrols these dark waters.

251
00:21:02,480 --> 00:21:03,480
Killer whales.

252
00:21:08,400 --> 00:21:10,920
They're not actually whales at all

253
00:21:10,920 --> 00:21:12,360
but giant dolphins,

254
00:21:12,360 --> 00:21:15,000
also known as orcas, devilfish.

255
00:21:18,960 --> 00:21:20,440
They live up to their name.

256
00:21:23,200 --> 00:21:25,280
They're the wolves of the sea,

257
00:21:25,280 --> 00:21:27,480
pack hunters that,
in some places,

258
00:21:27,480 --> 00:21:30,360
work together
to target the great whales.

259
00:21:34,160 --> 00:21:37,640
They've even been known to bring
down blue whales, the biggest

260
00:21:37,640 --> 00:21:42,160
creatures on Earth, but baby
humpbacks are a much easier target.

261
00:21:45,240 --> 00:21:48,920
Their ruthlessly efficient technique
is to separate a mother

262
00:21:48,920 --> 00:21:50,760
from her defenceless calf.

263
00:21:53,960 --> 00:21:57,400
The mother does her best to drive
them off, aggressively slamming

264
00:21:57,400 --> 00:22:01,120
the water's surface and lashing out
at her attackers.

265
00:22:03,440 --> 00:22:07,280
If the killer whales can separate
them, they'll leap onto her calf,

266
00:22:07,280 --> 00:22:10,880
pushing it underwater to drown it.

267
00:22:10,880 --> 00:22:12,600
The orcas are fast and agile,

268
00:22:12,600 --> 00:22:15,240
but moreover,
have numbers on their side.

269
00:22:26,080 --> 00:22:27,480
But help is at hand.

270
00:22:29,960 --> 00:22:31,080
The male whales.

271
00:22:32,960 --> 00:22:34,080
They close rank.

272
00:22:36,040 --> 00:22:39,600
Humpback whales are known
to demonstrate a remarkable ability

273
00:22:39,600 --> 00:22:41,600
to help others.

274
00:22:41,600 --> 00:22:45,920
They have immense strength
and some very effective weapons.

275
00:22:45,920 --> 00:22:49,560
Their tails contain some of the most
powerful muscles on Earth.

276
00:22:51,680 --> 00:22:54,920
A sideways slash
is a clear sign of aggression.

277
00:22:57,480 --> 00:22:58,800
And it works.

278
00:22:58,800 --> 00:23:03,280
The killer whales slink off
in search of easier prey.

279
00:23:07,600 --> 00:23:12,400
This seemingly altruistic behaviour
by humpbacks is well documented.

280
00:23:13,680 --> 00:23:16,880
One has even been seen lifting
a seal out of the water to keep

281
00:23:16,880 --> 00:23:19,840
it safe from killer whales.

282
00:23:19,840 --> 00:23:24,120
Another guided a human diver away
from a hunting tiger shark.

283
00:23:28,480 --> 00:23:32,200
After the dangerous encounter,
the mother reverses course

284
00:23:32,200 --> 00:23:36,560
and gently guides her calf back
to the safety of the shallows.

285
00:23:45,000 --> 00:23:48,480
Here, they're among the company
of other creatures that flock

286
00:23:48,480 --> 00:23:51,720
to Gorgona's waters.

287
00:23:51,720 --> 00:23:57,240
Shearwaters are long-distance flyers
that glide low over the waves.

288
00:23:57,240 --> 00:24:01,560
Like the whales, they seek warmer
islands on which to breed.

289
00:24:01,560 --> 00:24:03,240
But for the rest of the year,

290
00:24:03,240 --> 00:24:06,000
they can literally circumnavigate
the globe.

291
00:24:07,240 --> 00:24:11,240
Many will have fed alongside
the humpbacks in Antarctica.

292
00:24:14,160 --> 00:24:17,200
They're joined
by resident frigate birds.

293
00:24:18,520 --> 00:24:22,160
Frigates are amongst the most agile
aerial predators, riding

294
00:24:22,160 --> 00:24:25,360
the thermals to save energy
while they look for fish.

295
00:24:32,280 --> 00:24:35,680
Jumping tuna are a dead giveaway.

296
00:24:35,680 --> 00:24:39,920
The fast, predatory fish
drive smaller fish to the surface,

297
00:24:39,920 --> 00:24:42,360
and the birds flock
to the disturbance.

298
00:24:59,080 --> 00:25:03,040
Once they've filled their bellies,
the frigates return to their nests.

299
00:25:05,240 --> 00:25:09,440
The noisy colony is dominated
by males, showing off

300
00:25:09,440 --> 00:25:11,720
with their extraordinary displays.

301
00:25:13,480 --> 00:25:16,600
They inflate their throat sacs
to try to attract a mate.

302
00:25:19,040 --> 00:25:23,480
The males' balloons act as
amplifiers for their peculiar songs.

303
00:25:26,760 --> 00:25:30,760
Couples work together to build
the nest and brood their single

304
00:25:30,760 --> 00:25:33,560
chick for the first month or two.

305
00:25:33,560 --> 00:25:37,720
Then the males hand over
full child custody to the females.

306
00:25:39,440 --> 00:25:42,440
The mothers lavish
all their attention on the chick

307
00:25:42,440 --> 00:25:47,240
for nine months, the longest period
of parental care for any bird.

308
00:25:51,200 --> 00:25:56,200
By September, many are almost fully
grown and ready to leave the nest.

309
00:25:58,000 --> 00:26:00,400
But before they take
that final step,

310
00:26:00,400 --> 00:26:02,680
they must get used to 8ft wings

311
00:26:02,680 --> 00:26:05,280
that will soon carry them out
over the ocean.

312
00:26:09,040 --> 00:26:12,280
They won't develop the dark,
glossy feathers of their parents

313
00:26:12,280 --> 00:26:14,280
until they are mature enough
to breed,

314
00:26:14,280 --> 00:26:16,680
which won't be
for another decade.

315
00:26:19,480 --> 00:26:24,080
The frigate chicks thrive thanks
to the rich waters off Gorgona.

316
00:26:28,240 --> 00:26:33,360
The male humpback calf, now two
months old, isn't faring so well.

317
00:26:35,320 --> 00:26:39,040
He's become lethargic,
allowing barnacles and whale lice

318
00:26:39,040 --> 00:26:40,520
to colonise his head.

319
00:26:41,760 --> 00:26:44,920
It could mean that
his health is compromised.

320
00:26:51,320 --> 00:26:54,240
All humpback whales
have these hitchhikers.

321
00:26:56,720 --> 00:27:00,800
This species of barnacle,
a distant crustacean cousin of crabs

322
00:27:00,800 --> 00:27:03,400
and lobsters,
is unique to humpbacks.

323
00:27:07,000 --> 00:27:10,480
Like the whales, they start out life
as travellers -

324
00:27:10,480 --> 00:27:14,440
tiny, free-swimming larvae
that drift with the plankton.

325
00:27:17,960 --> 00:27:20,120
When they sense a passing whale,

326
00:27:20,120 --> 00:27:22,720
they attempt to latch on.

327
00:27:22,720 --> 00:27:25,600
The more active and fast swimming
the whale, the harder it is

328
00:27:25,600 --> 00:27:28,520
for the larval barnacles to attach.

329
00:27:32,800 --> 00:27:36,960
But the slowness of the calf
has meant he's an easy target.

330
00:27:39,480 --> 00:27:41,800
They've had time to secrete
a powerful cement

331
00:27:41,800 --> 00:27:43,920
and start to build
a more permanent home.

332
00:27:47,400 --> 00:27:52,040
In turn, the barnacles have allowed
lice to take hold, clustering

333
00:27:52,040 --> 00:27:55,400
around any scratches and scrapes
where they can feed on his skin.

334
00:27:57,160 --> 00:28:00,880
Animals that are sick or injured,
with suppressed immune systems,

335
00:28:00,880 --> 00:28:03,840
tend to have more lice
than healthy whales.

336
00:28:05,200 --> 00:28:08,840
And large infestations can damage
a whale's sensitive skin.

337
00:28:13,640 --> 00:28:16,720
It's a worrying sign
that the little whale's health

338
00:28:16,720 --> 00:28:20,360
has declined so dramatically
since his birth two months ago.

339
00:28:24,240 --> 00:28:27,800
He will have a tough time
shaking his unwanted passengers.

340
00:28:31,960 --> 00:28:35,960
It's thought healthy whales are able
to keep their levels of lice

341
00:28:35,960 --> 00:28:39,000
and barnacles low through breaching.

342
00:28:39,000 --> 00:28:43,960
There are many reasons whales
breach, including this pest control.

343
00:28:43,960 --> 00:28:47,920
The vast weight of a whale slapping
the surface is thought to knock

344
00:28:47,920 --> 00:28:49,720
off some of the hitchhikers,

345
00:28:49,720 --> 00:28:53,040
but the encrusted calf
hasn't yet learned to breach.

346
00:28:55,360 --> 00:28:57,880
He's seriously behind
in his development,

347
00:28:57,880 --> 00:28:59,560
and the clock's ticking.

348
00:29:00,760 --> 00:29:02,920
The stress
of the past couple of weeks

349
00:29:02,920 --> 00:29:04,840
may have been too much for him.

350
00:29:06,360 --> 00:29:09,440
He has just two more months
before he'll have to leave

351
00:29:09,440 --> 00:29:13,960
these warm waters and accompany
his mother on the 5,000 mile journey

352
00:29:13,960 --> 00:29:15,600
south to the Antarctic.

353
00:29:21,520 --> 00:29:24,880
If he's to survive the perilous
trip, he'll need to build up

354
00:29:24,880 --> 00:29:26,720
his strength...fast.

355
00:29:29,920 --> 00:29:34,280
His mother's job is to get him ready
for the journey, but all she can do

356
00:29:34,280 --> 00:29:38,000
is watch over him and keep up
the supply of rich, fatty milk.

357
00:29:50,720 --> 00:29:53,120
For the female green sea turtle,

358
00:29:53,120 --> 00:29:56,960
fulfilling her maternal duties
is much simpler.

359
00:29:56,960 --> 00:30:00,680
Under the cover of a moonlit
September night, she comes ashore

360
00:30:00,680 --> 00:30:01,800
to lay her eggs.

361
00:30:04,040 --> 00:30:08,600
Her slippers, usually paddles
in the water, become useful shovels,

362
00:30:08,600 --> 00:30:12,400
as she excavates a sandpit
between one and two feet deep.

363
00:30:16,600 --> 00:30:18,880
Her tail acts as a long ovipositor

364
00:30:18,880 --> 00:30:22,760
to drop the ping-pong-ball-sized
eggs into the nest -

365
00:30:22,760 --> 00:30:25,520
on average, about 150.

366
00:30:27,240 --> 00:30:30,320
The eggs are rubbery
to cushion their fall.

367
00:30:31,800 --> 00:30:34,680
With the clutch deposited,
she'll carefully cover them up

368
00:30:34,680 --> 00:30:36,880
before returning to the sea.

369
00:30:40,200 --> 00:30:42,320
Her maternal duties are done.

370
00:30:44,240 --> 00:30:48,120
It will take six to ten weeks
for the eggs to develop and hatch,

371
00:30:48,120 --> 00:30:49,960
and they will do so alone.

372
00:30:53,680 --> 00:30:58,280
Further offshore, a solitary female
humpback searches for a mate.

373
00:31:01,320 --> 00:31:04,000
Typically, humpbacks
have an interval of two or three

374
00:31:04,000 --> 00:31:06,880
years between offspring.

375
00:31:06,880 --> 00:31:11,120
Some females take a gap year
between calves and choose to stay

376
00:31:11,120 --> 00:31:15,400
in cooler Antarctic waters
and feed year-round.

377
00:31:15,400 --> 00:31:17,920
But when they're ready
to breed again, they return,

378
00:31:17,920 --> 00:31:19,480
and the males know it.

379
00:31:24,160 --> 00:31:28,640
Boisterous mating behaviour
reaches its peak in September,

380
00:31:28,640 --> 00:31:33,080
three months after the arrival
of calving females.

381
00:31:33,080 --> 00:31:34,560
Timing is everything.

382
00:31:37,280 --> 00:31:40,920
It's crucial that females get
pregnant now so their calves

383
00:31:40,920 --> 00:31:44,760
are born at the start of the season
next year and have the maximum time

384
00:31:44,760 --> 00:31:47,720
to grow before heading back
to Antarctica.

385
00:31:52,520 --> 00:31:56,080
With some females remaining
in Antarctic waters, there are often

386
00:31:56,080 --> 00:31:59,760
more males than females
at the breeding grounds.

387
00:31:59,760 --> 00:32:02,680
So the females that have made
the journey to Colombia

388
00:32:02,680 --> 00:32:04,320
can afford to be choosy.

389
00:32:05,600 --> 00:32:10,600
She pec-slaps, waving her huge,
16ft pectoral flipper in the air

390
00:32:10,600 --> 00:32:13,480
and then slapping it down
on the surface.

391
00:32:17,840 --> 00:32:21,000
The thunderous clap can be heard
underwater throughout

392
00:32:21,000 --> 00:32:22,480
the breeding grounds.

393
00:32:29,440 --> 00:32:32,960
It's not long before
several hopeful males gather.

394
00:32:36,120 --> 00:32:40,640
To stand a chance of mating,
a bull needs to impress the female,

395
00:32:40,640 --> 00:32:43,360
demonstrating
his strength and stamina.

396
00:32:45,320 --> 00:32:49,480
So she keeps on the move,
forcing the males to give chase.

397
00:32:55,240 --> 00:32:56,720
This is the heat run.

398
00:32:58,240 --> 00:33:02,440
Anything from two to 20 males
might join in, all trying

399
00:33:02,440 --> 00:33:03,720
to outdo each other.

400
00:33:07,520 --> 00:33:08,840
Aggression is rife.

401
00:33:14,840 --> 00:33:19,080
The males breach and slap
the surface, making as much noise

402
00:33:19,080 --> 00:33:21,880
as possible,
trying to intimidate the others.

403
00:33:32,120 --> 00:33:36,440
As their excitement cranks up,
they start to lash at each other

404
00:33:36,440 --> 00:33:37,640
with their tails.

405
00:33:44,320 --> 00:33:49,960
Slapping their chins on the water
is also a clear sign of aggression.

406
00:33:49,960 --> 00:33:52,080
They even ram their opponents.

407
00:33:59,040 --> 00:34:03,240
As the competition heats up,
the whales' speeds increase,

408
00:34:03,240 --> 00:34:05,960
eventually exceeding 12mph.

409
00:34:08,560 --> 00:34:12,520
Gradually, smaller,
less experienced or older males

410
00:34:12,520 --> 00:34:15,680
drop out, defeated.

411
00:34:15,680 --> 00:34:18,680
The last man standing
is the cream of the crop...

412
00:34:20,600 --> 00:34:22,560
..bearing the strongest genes

413
00:34:22,560 --> 00:34:25,320
the female has selected
to pass on to her calf.

414
00:34:31,920 --> 00:34:35,040
What happens next is one
of the humpback whale's

415
00:34:35,040 --> 00:34:36,400
many great mysteries.

416
00:34:38,240 --> 00:34:41,000
Mating has rarely been observed.

417
00:34:48,560 --> 00:34:52,920
While she's receptive, the female
may mate with several males.

418
00:34:54,880 --> 00:34:59,840
So often, a single male stays
by her side for weeks, trying

419
00:34:59,840 --> 00:35:02,320
to keep competitors at bay.

420
00:35:02,320 --> 00:35:04,080
He's known as an escort.

421
00:35:05,520 --> 00:35:08,480
With a limited season
in which to prove their worth,

422
00:35:08,480 --> 00:35:12,120
the rest of the males
can't afford to relax.

423
00:35:12,120 --> 00:35:15,800
The offshore waters remain
boisterous with potential breeders.

424
00:35:21,710 --> 00:35:23,750
It's now October.

425
00:35:23,750 --> 00:35:27,390
Sheltered in the bay, the barnacled
calf and his mother have been able

426
00:35:27,390 --> 00:35:30,070
to rest and recuperate for a month.

427
00:35:30,070 --> 00:35:33,470
He is looking a bit more energetic
and he's gained a little weight.

428
00:35:36,630 --> 00:35:41,390
Even better, his increased activity
has meant he's been able to dislodge

429
00:35:41,390 --> 00:35:44,070
most of his unwelcome hitchhikers.

430
00:35:44,070 --> 00:35:48,830
Whales shed their skin all the time,
especially when they're growing.

431
00:35:48,830 --> 00:35:52,070
Now that the calf is once again
piling on the pounds,

432
00:35:52,070 --> 00:35:55,470
he's replacing
his skin cells faster.

433
00:35:55,470 --> 00:35:58,950
As he loses his old skin layer,
it's taking some of the barnacles

434
00:35:58,950 --> 00:36:01,070
and lice infestation with it.

435
00:36:02,470 --> 00:36:05,270
He's grown more than 15 inches
in the last month.

436
00:36:07,230 --> 00:36:10,750
Slowly but surely,
the little calf is catching up.

437
00:36:14,470 --> 00:36:17,830
The youngster nuzzles
against his mother.

438
00:36:17,830 --> 00:36:20,590
Calves usually rest
above their mother's jaw to keep

439
00:36:20,590 --> 00:36:23,630
them safe from attack from below.

440
00:36:23,630 --> 00:36:27,830
He swims under, perhaps trying
to dislodge some of his parasites

441
00:36:27,830 --> 00:36:30,110
against his mother's bumpy chin.

442
00:36:31,630 --> 00:36:35,710
Humpbacks are very tactile animals,
and for the past 12 weeks,

443
00:36:35,710 --> 00:36:39,270
mother and son have been
in constant physical contact.

444
00:36:39,270 --> 00:36:42,230
But slowly,
that's starting to change.

445
00:36:45,110 --> 00:36:49,550
As he grows, the calf needs to begin
mastering the life skills he'll need

446
00:36:49,550 --> 00:36:51,550
once he leaves his mother's side,

447
00:36:51,550 --> 00:36:52,910
including learning

448
00:36:52,910 --> 00:36:55,750
some of the humpback's
more dramatic moves.

449
00:36:57,870 --> 00:37:01,030
His mother demonstrates,
and he tries to copy.

450
00:37:07,710 --> 00:37:10,910
He starts with some
of the simpler communication moves.

451
00:37:12,590 --> 00:37:15,870
Pec-slapping and tail lobbing.

452
00:37:30,590 --> 00:37:35,110
Confident at pulling off the basics,
the young calf ups the ante,

453
00:37:35,110 --> 00:37:39,710
attempting to master the most
impressive humpback feat, a breach.

454
00:37:50,110 --> 00:37:54,750
Slowly but surely, he manages
to lift his head clear of the water.

455
00:38:00,270 --> 00:38:05,670
The crash landing from a successful
breach can be heard many miles away.

456
00:38:05,670 --> 00:38:09,910
If the calf can succeed,
he'll be a step closer to maturity.

457
00:38:14,830 --> 00:38:19,310
This training also helps build up
his muscles for his epic journey

458
00:38:19,310 --> 00:38:23,550
south and has the added benefit
of dislodging a few more barnacles

459
00:38:23,550 --> 00:38:24,550
along the way.

460
00:38:29,190 --> 00:38:32,350
As the whale calf grows,
he gains confidence.

461
00:38:35,150 --> 00:38:36,790
He's now three months old

462
00:38:36,790 --> 00:38:40,470
and ready to start properly
exploring his surroundings.

463
00:38:42,750 --> 00:38:44,750
Below him, the reef teems with life.

464
00:38:50,310 --> 00:38:54,070
The shallow waters receive
plenty of the sun's energy

465
00:38:54,070 --> 00:38:55,390
for corals to grow.

466
00:38:57,590 --> 00:39:00,470
The whales themselves
might significantly contribute

467
00:39:00,470 --> 00:39:02,950
to the health of the reef.

468
00:39:02,950 --> 00:39:07,550
When they defecate, their waste
feeds algal blooms, which the corals

469
00:39:07,550 --> 00:39:10,030
filter from the water as food.

470
00:39:10,030 --> 00:39:13,590
These microscopic algae
in their billions produce much

471
00:39:13,590 --> 00:39:15,910
of the oxygen in the atmosphere.

472
00:39:15,910 --> 00:39:21,030
As the algal blooms photosynthesise,
they also remove carbon dioxide

473
00:39:21,030 --> 00:39:25,390
from the air, so indirectly,
the young whale is helping to combat

474
00:39:25,390 --> 00:39:29,190
one of the world's biggest
challenges, climate change.

475
00:39:31,550 --> 00:39:36,070
By fuelling these algal blooms,
whales might be responsible

476
00:39:36,070 --> 00:39:40,470
for the removal of 440,000 tonnes
of carbon each year.

477
00:39:41,870 --> 00:39:45,870
The whale-fed algae then feeds
plankton and small fish,

478
00:39:45,870 --> 00:39:48,550
which in turn feed bigger ones.

479
00:39:48,550 --> 00:39:52,030
It's a giant feast,
partly fuelled by the whales.

480
00:40:00,030 --> 00:40:04,350
By late October, there are signs
of new life stirring in the sand.

481
00:40:06,350 --> 00:40:11,670
Like a clockwork toy, a tiny sea
turtle paddles with all his might.

482
00:40:11,670 --> 00:40:12,990
And he's not alone.

483
00:40:14,270 --> 00:40:18,430
More than 100 emerge en masse,
swarming down the beach.

484
00:40:20,390 --> 00:40:23,430
Most of the turtles born here
are from the nests

485
00:40:23,430 --> 00:40:27,670
of olive ridleys, a species
that commonly breeds on Gorgona.

486
00:40:32,070 --> 00:40:36,270
But among them is something
very rare for the island.

487
00:40:36,270 --> 00:40:38,430
A nest of green sea turtles.

488
00:40:43,590 --> 00:40:46,510
There are only a few records
of them breeding here.

489
00:40:58,590 --> 00:41:02,350
While turtles and whales
share their destiny in the ocean,

490
00:41:02,350 --> 00:41:05,790
their strategies for success
are polar opposites.

491
00:41:07,270 --> 00:41:11,030
Whales produce a single infant
at a time and invest

492
00:41:11,030 --> 00:41:13,550
all their energy
in helping it develop

493
00:41:13,550 --> 00:41:15,670
until it can survive on its own.

494
00:41:21,550 --> 00:41:25,870
Sea turtles play the numbers game,
laying hundreds of eggs

495
00:41:25,870 --> 00:41:28,070
and abandoning them to chance.

496
00:41:31,870 --> 00:41:33,470
The odds are slim.

497
00:41:33,470 --> 00:41:35,750
There are dangers at every turn.

498
00:41:38,190 --> 00:41:42,510
It's a desperate race to the water
before birds and other beach hunters

499
00:41:42,510 --> 00:41:44,070
cut short their lives.

500
00:41:47,510 --> 00:41:49,710
The frigates are back.

501
00:41:49,710 --> 00:41:52,870
The hungry birds glide
over the beaches, looking

502
00:41:52,870 --> 00:41:54,110
for vulnerable hatchlings.

503
00:41:56,430 --> 00:41:59,070
And the dangers aren't limited
to the sky.

504
00:42:00,430 --> 00:42:05,310
On the beach, a small but voracious
predator lurks in its burrow.

505
00:42:05,310 --> 00:42:09,590
If the red ghost crab spots any sign
of weakness, it strikes.

506
00:42:16,510 --> 00:42:18,190
It sees a straggler.

507
00:42:22,670 --> 00:42:26,670
But struggles to penetrate
the hatchling's leathery skin.

508
00:42:27,750 --> 00:42:31,390
But it's not the only predator
eyeing up the turtle.

509
00:42:32,990 --> 00:42:36,710
To avoid becoming a snack himself,
the crab retreats.

510
00:42:39,190 --> 00:42:42,550
The little turtle grabs the chance
to escape and makes a dash

511
00:42:42,550 --> 00:42:43,550
for the water.

512
00:42:46,830 --> 00:42:51,070
Of those that make it, they face
decades of danger, as they swim

513
00:42:51,070 --> 00:42:54,230
the ocean's currents
before reaching maturity.

514
00:42:59,750 --> 00:43:02,830
Only one in every 1,000
will make it.

515
00:43:06,030 --> 00:43:09,590
Those lucky few that survive
will eventually return to the bay

516
00:43:09,590 --> 00:43:12,950
on the east of Gorgona
to lay eggs of their own.

517
00:43:18,150 --> 00:43:22,310
By the end of October,
the adult whales are getting thin.

518
00:43:24,270 --> 00:43:27,990
They've been living off their fat
reserves for five months or more,

519
00:43:27,990 --> 00:43:30,390
since they left Antarctica.

520
00:43:30,390 --> 00:43:33,390
Now a 6-12 week return journey
lies ahead.

521
00:43:34,950 --> 00:43:37,830
They need food, soon,
and lots of it.

522
00:43:40,950 --> 00:43:43,870
The time's coming for them
to migrate back south

523
00:43:43,870 --> 00:43:46,910
for the summertime feast of krill.

524
00:43:46,910 --> 00:43:50,870
Females that have successfully mated
are the first to depart,

525
00:43:50,870 --> 00:43:53,950
followed by mothers
and their calves.

526
00:43:53,950 --> 00:43:57,550
With no-one left to mate with,
the males follow on.

527
00:44:01,710 --> 00:44:05,910
The young male and his mother
are among the last to leave.

528
00:44:05,910 --> 00:44:08,030
They wait well into November.

529
00:44:10,950 --> 00:44:12,990
It's taken him longer to bulk up

530
00:44:12,990 --> 00:44:16,350
in preparation for the frigid
waters of Antarctica.

531
00:44:18,910 --> 00:44:20,550
Finally, he's ready.

532
00:44:24,070 --> 00:44:29,190
He's now nearly 26ft long,
well insulated with blubber,

533
00:44:29,190 --> 00:44:31,110
and his swimming is strong.

534
00:44:33,590 --> 00:44:37,270
He'll be weaned over the next few
months, once he is adept at feeding

535
00:44:37,270 --> 00:44:39,190
on plankton and small fish.

536
00:44:43,270 --> 00:44:46,790
By his first birthday,
he'll likely be on his own.

537
00:44:50,310 --> 00:44:52,110
But he still has a lot to learn.

538
00:44:54,390 --> 00:44:56,310
He stays close to his mother,

539
00:44:56,310 --> 00:44:58,670
copying her every move,

540
00:44:58,670 --> 00:45:01,270
as their epic journey
gets under way.

541
00:45:04,190 --> 00:45:07,430
He'll swim the ocean
for at least five years

542
00:45:07,430 --> 00:45:09,350
before he's ready to breed.

543
00:45:12,790 --> 00:45:16,510
Then he'll return to Gorgona
and join the chase.

544
00:45:18,150 --> 00:45:23,510
A mighty giant, ensuring the future
of Colombia's humpback whales.

545
00:45:42,110 --> 00:45:45,110
Subtitles by Red Bee Media