1
00:00:20,960 --> 00:00:25,640
'It's hard to describe
how still it is

2
00:00:25,640 --> 00:00:29,960
'on a glacier surrounded
by a fresh blanket of snow.'

3
00:00:32,960 --> 00:00:34,960
Which makes the fact that I'm moving

4
00:00:34,960 --> 00:00:37,960
at 490,000mph

5
00:00:37,960 --> 00:00:39,960
all the more extraordinary.

6
00:00:39,960 --> 00:00:42,960
But I, like everyone, like you,

7
00:00:42,960 --> 00:00:47,960
am hurtling through space on
our annual journey around the sun.

8
00:00:47,960 --> 00:00:50,960
'For the first time,

9
00:00:50,960 --> 00:00:55,160
'this series explores
how all life on our planet...

10
00:00:56,960 --> 00:00:59,160
'..is shaped by this orbit.

11
00:01:00,960 --> 00:01:03,960
'How where you are on Earth...

12
00:01:06,960 --> 00:01:09,640
'..makes a world of difference.

13
00:01:09,640 --> 00:01:12,960
'And no matter how far apart...

14
00:01:13,960 --> 00:01:17,960
'..how everything is connected.

15
00:01:17,960 --> 00:01:19,960
'Epic weather systems...

16
00:01:21,960 --> 00:01:24,960
'..trigger seasonal spectacles...

17
00:01:25,960 --> 00:01:28,960
'..driving animals to move...

18
00:01:32,960 --> 00:01:34,800
'..to fight...

19
00:01:37,480 --> 00:01:39,960
'..and even to love.

20
00:01:44,800 --> 00:01:48,320
'Filmed across
more than 60 locations...

21
00:01:49,960 --> 00:01:53,960
'..we'll see
this unique annual journey

22
00:01:53,960 --> 00:01:56,960
'through the eyes
of incredible animal families...

23
00:01:58,960 --> 00:02:04,960
'..as they take on everything
the seasons can throw at them.

24
00:02:31,960 --> 00:02:34,960
'It's high
in the Northern Hemisphere

25
00:02:34,960 --> 00:02:36,960
'where winter hits earliest.

26
00:02:43,960 --> 00:02:45,000
'By late-October,

27
00:02:45,000 --> 00:02:47,960
'most animals
have already fled south

28
00:02:47,960 --> 00:02:49,960
'to escape the brutal cold.

29
00:02:54,800 --> 00:02:56,960
'Only the toughest remain.

30
00:03:03,480 --> 00:03:06,960
'For now, this mother
and her two-year-old cub

31
00:03:06,960 --> 00:03:09,960
'still have time to play.

32
00:03:22,800 --> 00:03:26,960
'It will be the last winter
they spend together.

33
00:03:29,000 --> 00:03:31,960
'Polar bears are solitary animals...

34
00:03:33,960 --> 00:03:37,960
'..and she only has until spring
to prepare her cub...

35
00:03:38,960 --> 00:03:40,960
'..for a life alone.

36
00:03:46,800 --> 00:03:49,960
'Since birth,
he's followed in her footsteps...

37
00:03:51,960 --> 00:03:55,960
'..and she's had to hunt
for both of them.

38
00:04:07,960 --> 00:04:13,480
'The ice in Svalbard's fjords
acts as their main hunting platform.

39
00:04:14,960 --> 00:04:18,640
'But right now,
it's only just forming...

40
00:04:20,960 --> 00:04:25,960
'..and opportunities
are thin on the ground.

41
00:04:28,960 --> 00:04:30,960
'A ringed seal.

42
00:04:34,960 --> 00:04:36,480
'A lifeline.

43
00:04:48,160 --> 00:04:50,960
'The cub knows to stay back.

44
00:05:25,960 --> 00:05:28,960
'Every week without food...

45
00:05:28,960 --> 00:05:32,960
'mother and cub
lose a tenth of their weight.

46
00:05:35,960 --> 00:05:37,960
'Tough times lie ahead.

47
00:05:43,960 --> 00:05:46,960
'The seasonal challenges
animals face

48
00:05:46,960 --> 00:05:51,960
'are all created
by a quirk unique to our planet.'

49
00:05:51,960 --> 00:05:55,960
Our journey
around that nuclear reactor

50
00:05:55,960 --> 00:05:59,960
affects almost all life on Earth.

51
00:05:59,960 --> 00:06:02,640
And as we circle it,

52
00:06:02,640 --> 00:06:05,960
we do so on a titled axis.

53
00:06:06,960 --> 00:06:10,480
'It's this that creates the seasons.

54
00:06:10,480 --> 00:06:12,960
'During summer,
the Northern Hemisphere

55
00:06:12,960 --> 00:06:14,960
'leans towards the sun.

56
00:06:15,960 --> 00:06:20,960
'But six months later,
the north tilts away from the sun...

57
00:06:21,960 --> 00:06:24,960
'..and days become shorter
and darker.'

58
00:06:28,960 --> 00:06:32,960
Despite being clad head to foot
in specialist winter gear,

59
00:06:32,960 --> 00:06:36,000
I wouldn't survive a night
on this hillside.

60
00:06:37,960 --> 00:06:39,960
'Thankfully, I won't have to.

61
00:06:42,960 --> 00:06:45,960
'But this mother and cub
must be prepared to face

62
00:06:45,960 --> 00:06:49,960
'some of the toughest conditions
on the planet.

63
00:06:51,960 --> 00:06:54,960
'It's the last time
they'll see the sun this year.

64
00:07:07,160 --> 00:07:10,320
'Polar winter is here.

65
00:07:12,320 --> 00:07:16,960
'This one night
will last for more than a 100 days.

66
00:07:21,480 --> 00:07:25,960
'Somehow, this mother
will have to find enough food

67
00:07:25,960 --> 00:07:30,160
'to see them through
the dark times ahead.

68
00:07:35,960 --> 00:07:38,960
'When it's winter
in the Northern Hemisphere,

69
00:07:38,960 --> 00:07:41,960
'at the other end of the Earth,
it's summer.

70
00:07:42,960 --> 00:07:45,960
'The Southern Hemisphere
is tilted towards the sun...

71
00:07:47,960 --> 00:07:52,960
'..bathed in its warmth and light,
and teeming with life.

72
00:07:58,960 --> 00:08:01,640
'After a two-week fishing trip,

73
00:08:01,640 --> 00:08:03,960
'these king penguins
are heading home

74
00:08:03,960 --> 00:08:06,960
'to a tiny speck of land,

75
00:08:06,960 --> 00:08:10,960
'1,000 miles south
of the African continent.

76
00:08:12,320 --> 00:08:15,960
'Some have swum up to 4,000 miles

77
00:08:15,960 --> 00:08:17,960
'in search of food.

78
00:08:46,960 --> 00:08:48,960
'They're home.

79
00:08:49,960 --> 00:08:52,960
'But the moment
they set foot on land,

80
00:08:52,960 --> 00:08:55,160
'all that grace disappears.

81
00:09:06,960 --> 00:09:09,960
'Still, he needs to keep moving.

82
00:09:10,960 --> 00:09:12,800
'After so long at sea,

83
00:09:12,800 --> 00:09:15,960
'he's desperate to reunite
with his mate.

84
00:09:17,960 --> 00:09:22,000
'But a million other penguins
have had the same idea.

85
00:09:23,480 --> 00:09:24,960
'Oh, my!

86
00:09:24,960 --> 00:09:27,960
'This might take some time.

87
00:09:29,160 --> 00:09:31,640
'It's December,

88
00:09:31,640 --> 00:09:34,960
'and in the Southern Hemisphere,
that means summer.

89
00:09:34,960 --> 00:09:38,960
'A tenth of all the king penguins
on Earth

90
00:09:38,960 --> 00:09:42,160
'have come to Marion Island
to breed.

91
00:09:43,960 --> 00:09:47,160
'And this male
needs to find his mate in the crowd.

92
00:09:48,640 --> 00:09:50,960
It may seem an impossible task,

93
00:09:50,960 --> 00:09:53,960
'but king penguins
have an extraordinary ability

94
00:09:53,960 --> 00:09:55,960
'to locate one another.

95
00:09:55,960 --> 00:10:00,960
'He can filter the cacophony
of half a million birds

96
00:10:00,960 --> 00:10:03,960
'to isolate her call.

97
00:10:10,960 --> 00:10:14,960
It's known as
the cocktail party effect.

98
00:10:14,960 --> 00:10:18,960
'Rather apt
for a bird in a dinner suit.

99
00:10:20,640 --> 00:10:22,960
'Hearing her is one thing.

100
00:10:22,960 --> 00:10:25,960
'Getting to her another.

101
00:10:27,960 --> 00:10:31,960
'Every corner of the colony
is contested.

102
00:10:34,960 --> 00:10:38,320
'And penguins
were enforcing social distancing

103
00:10:38,320 --> 00:10:40,160
'long before we'd heard of it.

104
00:11:20,000 --> 00:11:23,480
'Finally, reunited.

105
00:11:25,960 --> 00:11:28,960
'She's waited more than two weeks,

106
00:11:28,960 --> 00:11:35,960
'going without food or water,
to guard their newly-laid egg.

107
00:11:39,960 --> 00:11:42,960
'Now it's his turn to care for it.

108
00:11:49,960 --> 00:11:55,800
'This egg is the pair's only chance
to raise a chick this year.

109
00:11:56,960 --> 00:12:01,960
'Just getting it to hatch
will take incredible devotion.

110
00:12:05,960 --> 00:12:08,960
'Taking turns to sit on the egg

111
00:12:08,960 --> 00:12:12,640
'while the other feeds
in the summer seas.

112
00:12:14,960 --> 00:12:16,960
'This far south,

113
00:12:16,960 --> 00:12:20,000
'the sun's rays hit Marion Island
at an angle.

114
00:12:21,960 --> 00:12:23,960
'But further north,

115
00:12:23,960 --> 00:12:27,960
'the Earth's tilt
means that in Southern Africa,

116
00:12:27,960 --> 00:12:33,960
'along the Tropic of Capricorn,
the sun is directly overhead.

117
00:12:33,960 --> 00:12:37,320
'Here, its energy
is at its most concentrated,

118
00:12:37,320 --> 00:12:40,320
'super-heating the land,

119
00:12:40,320 --> 00:12:42,960
'driving cloud formation

120
00:12:42,960 --> 00:12:46,960
'and bringing the rains
to Botswana.'

121
00:12:58,960 --> 00:13:02,960
'There couldn't be
a more perfect time to be born.

122
00:13:04,960 --> 00:13:07,960
'Much of an elephant's existence

123
00:13:07,960 --> 00:13:10,960
'revolves around
the search for water.

124
00:13:11,960 --> 00:13:15,960
'During the rainy season
in the Southern Hemisphere,

125
00:13:15,960 --> 00:13:21,480
'there's so much of it that life
is about as easy as it gets.

126
00:13:27,960 --> 00:13:30,960
'But it doesn't stay like this
for long.

127
00:13:34,000 --> 00:13:37,960
This one-month-old baby elephant's
first year

128
00:13:37,960 --> 00:13:40,960
'will be the most challenging
of his whole life.

129
00:13:51,960 --> 00:13:55,960
'The savannahs are at their lushest,

130
00:13:55,960 --> 00:13:57,960
'the rivers at their fullest,

131
00:13:57,960 --> 00:14:02,960
'and there's a baby boom
in Botswana.

132
00:14:11,960 --> 00:14:15,960
'There's a world of new life
to discover.

133
00:14:22,960 --> 00:14:26,320
'With refreshment at every turn.

134
00:14:27,960 --> 00:14:29,960
'Just as well.

135
00:14:30,960 --> 00:14:35,960
'An adult elephant
needs over 200 litres a day.

136
00:14:45,960 --> 00:14:49,800
'But the baby gets all he needs
from milk.

137
00:14:49,800 --> 00:14:52,960
'So a trip to the river
means it's time to play.

138
00:15:03,960 --> 00:15:06,960
'Life may seem idyllic now,

139
00:15:06,960 --> 00:15:10,960
'but danger is never far away.

140
00:15:15,960 --> 00:15:17,960
'There are lion prides

141
00:15:17,960 --> 00:15:20,960
'that specialise
in taking down elephants.

142
00:15:20,960 --> 00:15:25,000
'And it's the smallest
that are the most vulnerable.

143
00:15:52,960 --> 00:15:54,960
'But during the wet season,

144
00:15:54,960 --> 00:15:58,960
'there's plenty of easier prey
for the lions to chase.

145
00:16:00,960 --> 00:16:07,960
'Botswana has distinct periods
of summer rain and winter sun.

146
00:16:07,960 --> 00:16:09,960
'But along the equator,

147
00:16:09,960 --> 00:16:12,960
'the seasons, as we know them,
all but disappear.

148
00:16:14,480 --> 00:16:18,800
'Consistent sunlight all year round

149
00:16:18,800 --> 00:16:21,960
'creates the ideal conditions

150
00:16:21,960 --> 00:16:24,960
'for tropical rainforests to thrive.

151
00:16:26,960 --> 00:16:29,960
'Animals living here
don't waste precious energy

152
00:16:29,960 --> 00:16:34,960
'surviving seasonal extremes,
or migrating to escape them.

153
00:16:35,960 --> 00:16:39,960
'Instead,
they can put it into something

154
00:16:39,960 --> 00:16:42,960
'a little bit more... fabulous.

155
00:16:43,960 --> 00:16:48,160
'From the weird...
to the wonderfully colourful.

156
00:16:52,960 --> 00:16:56,960
'In the jungles of Papua New Guinea
and Northern Australia,

157
00:16:56,960 --> 00:17:00,960
'there are a few
who focus on more artistic pursuits.

158
00:17:02,960 --> 00:17:05,960
'He may seem a little drab

159
00:17:05,960 --> 00:17:07,960
'compared
to other birds of paradise...

160
00:17:08,960 --> 00:17:12,960
'..but he's called
a magnificent riflebird

161
00:17:12,960 --> 00:17:14,480
'for a reason.

162
00:17:16,960 --> 00:17:22,160
'He's dedicated his entire life
to the art of seduction.

163
00:17:25,640 --> 00:17:29,960
'But to really shine,
he needs a partner.'

164
00:17:42,320 --> 00:17:45,960
'Ah! The first audience of the day.

165
00:17:48,960 --> 00:17:52,960
'And this branch, his personal stage

166
00:17:52,960 --> 00:17:57,960
'for a routine
he's been perfecting for years.

167
00:17:58,960 --> 00:18:02,320
'It's rarely been seen,
let alone filmed.

168
00:18:20,480 --> 00:18:22,960
'With special wing feathers,

169
00:18:22,960 --> 00:18:25,800
'he puts on
a shape-shifting display.

170
00:18:28,960 --> 00:18:32,960
'But not every riflebird
is what they seem.

171
00:18:35,960 --> 00:18:38,960
'And that's no she.

172
00:18:44,160 --> 00:18:47,960
'Juvenile males
look and act like females

173
00:18:47,960 --> 00:18:50,640
'to cheat a front-row seat

174
00:18:50,640 --> 00:18:52,960
'and learn from the best.

175
00:18:54,160 --> 00:18:58,960
'It can take five years of study
to master this dance.

176
00:19:07,320 --> 00:19:10,960
'But once he sees through
the charade...

177
00:19:12,160 --> 00:19:16,640
'..he has no moves left to teach

178
00:19:16,640 --> 00:19:19,480
'but the cold shoulder.

179
00:19:23,960 --> 00:19:26,960
'No matter how much
his fan looks up to him.

180
00:19:36,800 --> 00:19:41,960
'Here, the tropical sun shines
more or less 12 hours a day...

181
00:19:42,960 --> 00:19:44,960
'..all year round.

182
00:19:45,960 --> 00:19:49,960
'But far to the north,
in the Arctic...

183
00:19:50,960 --> 00:19:54,960
'..there is nothing but darkness.

184
00:19:59,960 --> 00:20:01,960
'It's the winter solstice.

185
00:20:02,960 --> 00:20:06,800
'The shortest day of the year.

186
00:20:09,960 --> 00:20:11,960
'When the Northern Hemisphere

187
00:20:11,960 --> 00:20:16,320
'is tilted as far away from the sun
as it can be.

188
00:20:20,480 --> 00:20:22,000
'From this point onwards...

189
00:20:23,960 --> 00:20:26,960
'..days begin to get longer.

190
00:20:28,800 --> 00:20:32,160
'But this polar bear
won't see the sun rise

191
00:20:32,160 --> 00:20:35,160
'for another 56 days.

192
00:20:37,800 --> 00:20:41,160
'If it even survives that long.

193
00:20:50,960 --> 00:20:55,160
'The relentless search for food
continues

194
00:20:55,160 --> 00:20:58,480
'for the polar bear mother and cub.

195
00:21:00,960 --> 00:21:04,800
'A reindeer
fallen victim to the winter storms

196
00:21:04,800 --> 00:21:06,960
'offers some relief.

197
00:21:06,960 --> 00:21:12,960
'But together, they need
more than 170,000 calories a week.

198
00:21:14,960 --> 00:21:18,960
'An adult reindeer
provides less than half that.

199
00:21:25,960 --> 00:21:28,960
'If they're ever
going to see the sun again,

200
00:21:28,960 --> 00:21:33,160
'she'll need to enforce
some portion control.

201
00:21:38,480 --> 00:21:42,160
'While the sun may be long gone
from the Arctic,

202
00:21:42,160 --> 00:21:44,960
'its presence isn't forgotten.

203
00:21:48,960 --> 00:21:52,960
'Solar winds engulf our planet.

204
00:21:52,960 --> 00:21:57,960
'And these latitudes bear witness
to a display on a planetary scale.

205
00:21:59,160 --> 00:22:01,960
'The northern lights.

206
00:22:02,960 --> 00:22:06,960
'When charged particles
collide with Earth's magnetic field

207
00:22:06,960 --> 00:22:09,960
'at millions of miles an hour,

208
00:22:09,960 --> 00:22:13,960
'they release
enormous amounts of energy.

209
00:22:39,160 --> 00:22:42,960
'These lights
are the only way we ever see

210
00:22:42,960 --> 00:22:45,160
'this invisible magnetic force.

211
00:22:47,960 --> 00:22:50,160
'Yet we are still discovering

212
00:22:50,160 --> 00:22:54,800
'how fundamental it is
to life on Earth.

213
00:22:58,960 --> 00:23:03,960
'Recent studies suggest
it may even help one animal

214
00:23:03,960 --> 00:23:05,960
'catch its next meal.

215
00:23:10,960 --> 00:23:15,800
'Winter storms
have covered this red fox's home

216
00:23:15,800 --> 00:23:19,960
'in a blanket of snow
three feet deep...

217
00:23:21,960 --> 00:23:25,960
'..and hidden the rodents
it usually hunts.

218
00:23:28,960 --> 00:23:30,960
'For some animals,

219
00:23:30,960 --> 00:23:33,960
'this might be a barrier
too great to overcome.

220
00:23:36,960 --> 00:23:40,960
'But a fox is cunning
and has excellent hearing.

221
00:24:03,960 --> 00:24:07,960
'It's trial... and error.

222
00:24:23,160 --> 00:24:27,960
'But there is one thing he can do
to improve his chances.

223
00:24:29,960 --> 00:24:33,960
'Scientists believe red foxes
have a sixth sense

224
00:24:33,960 --> 00:24:38,960
'for the same magnetic force
that causes the northern lights.

225
00:24:38,960 --> 00:24:43,960
'And they can use it to triangulate
their prey's position.

226
00:24:49,960 --> 00:24:53,960
'Pointing to the north-east,
he waits for the sound of his prey

227
00:24:53,960 --> 00:24:56,960
'to cross the angle
of the magnetic field.

228
00:24:57,960 --> 00:24:59,960
'The sweet spot.

229
00:25:19,960 --> 00:25:25,320
'Using this technique,
his hit rate increases fourfold.

230
00:25:27,960 --> 00:25:30,960
'In January's bitter cold,

231
00:25:30,960 --> 00:25:34,960
'it can make the difference
between life and death.

232
00:25:37,480 --> 00:25:40,960
'After weeks
with little energy from the sun

233
00:25:40,960 --> 00:25:44,480
'the Northern Hemisphere
continues to cool.

234
00:25:57,640 --> 00:26:01,960
'Many animals that migrated south
to avoid the cold

235
00:26:01,960 --> 00:26:04,960
'are just arriving
at their destinations.

236
00:26:04,960 --> 00:26:10,960
'Where better for a spot of winter
sun than the coast of Florida?

237
00:26:15,960 --> 00:26:19,960
'Home to luxury apartments,

238
00:26:19,960 --> 00:26:22,800
'golden sands...

239
00:26:23,960 --> 00:26:27,960
'..and warm tropical waters.

240
00:26:28,960 --> 00:26:32,960
'A favourite not just for
America's holiday-makers,

241
00:26:32,960 --> 00:26:35,960
'but blacktip sharks, too.

242
00:26:37,960 --> 00:26:40,960
'12,000 of them.

243
00:26:49,960 --> 00:26:51,960
'Just like everyone else,

244
00:26:51,960 --> 00:26:55,960
'they're making the most
of the warm water.

245
00:26:55,960 --> 00:26:59,960
'But there's trouble in paradise.

246
00:27:02,960 --> 00:27:05,960
'Great hammerhead sharks,

247
00:27:05,960 --> 00:27:08,640
'up to six metres long,

248
00:27:08,640 --> 00:27:12,480
'have been waiting all year
for this seasonal feast.

249
00:27:16,960 --> 00:27:18,960
'For the blacktips,

250
00:27:18,960 --> 00:27:23,960
'travelling in numbers is far safer

251
00:27:23,960 --> 00:27:25,960
'than being caught out alone.

252
00:27:30,960 --> 00:27:35,960
'Together, they have more chance
of spotting danger.

253
00:27:39,960 --> 00:27:42,960
'But with eyes
on the sides of its head,

254
00:27:42,960 --> 00:27:46,960
'a hammerhead sees
in almost every direction.

255
00:27:51,960 --> 00:27:54,960
'They scan for weakness...

256
00:27:57,960 --> 00:28:00,800
'..constantly testing the school.

257
00:28:11,960 --> 00:28:14,960
'One wrong move...

258
00:28:15,960 --> 00:28:17,960
'..is all it takes.

259
00:28:44,320 --> 00:28:46,960
'Despite the risks,

260
00:28:46,960 --> 00:28:48,960
'the promise of food and warmth

261
00:28:48,960 --> 00:28:52,320
'makes the journey south worthwhile.

262
00:28:56,960 --> 00:29:01,960
'Constant sunlight provides a refuge
for animals throughout the tropics.

263
00:29:02,960 --> 00:29:05,960
'But for those
that live here year-round,

264
00:29:05,960 --> 00:29:09,160
'there are
more pressing matters at hand.

265
00:29:12,480 --> 00:29:14,960
'The magnificent riflebird

266
00:29:14,960 --> 00:29:17,960
'is still looking for love.'

267
00:29:21,960 --> 00:29:25,960
'A female... surely.

268
00:29:30,320 --> 00:29:33,960
'He needs to entice her
onto the stage.

269
00:29:38,960 --> 00:29:40,320
'A good start.

270
00:29:43,960 --> 00:29:46,960
'But she holds all the cards.

271
00:29:46,960 --> 00:29:50,960
'She'll only mate
with the most impressive male.

272
00:29:51,960 --> 00:29:55,960
'Beauty is in the eye
of the beholder.

273
00:29:56,960 --> 00:29:59,160
'Well, behold this!'

274
00:30:31,960 --> 00:30:33,960
'A flutter of the wings

275
00:30:33,960 --> 00:30:36,640
'shows she approves.

276
00:30:41,960 --> 00:30:44,960
'It's time for his signature move.'

277
00:31:08,960 --> 00:31:11,640
'It seems to do the trick.

278
00:31:17,960 --> 00:31:20,000
'And after all that,

279
00:31:20,000 --> 00:31:23,320
'he may never dance for her again.

280
00:31:24,960 --> 00:31:26,960
'Her loss!'

281
00:31:27,960 --> 00:31:30,960
'There are plenty more birds
in paradise.

282
00:31:34,960 --> 00:31:38,960
'As our planet continues
its journey around the sun,

283
00:31:38,960 --> 00:31:41,960
'the seasons start to turn.

284
00:31:46,960 --> 00:31:49,960
'Over 1,000 miles
south of the equator,

285
00:31:49,960 --> 00:31:53,960
'the rainy season will soon end.

286
00:31:56,960 --> 00:31:59,960
'Fewer clouds in the sky

287
00:31:59,960 --> 00:32:03,960
'means less protection
from the searing sun.

288
00:32:05,960 --> 00:32:09,960
'So the herd seeks shade
in the bush.

289
00:32:20,960 --> 00:32:25,960
'The baby elephant's
grown more confident and curious.

290
00:32:36,960 --> 00:32:40,960
'He's still not got the hang
of that trunk, though.

291
00:32:45,960 --> 00:32:49,960
'It's one of the most complex organs
on Earth.

292
00:32:49,960 --> 00:32:53,960
'Delicate enough
to pluck a blade of grass,

293
00:32:53,960 --> 00:32:56,960
'strong enough to lift 250 kilos.

294
00:32:59,480 --> 00:33:02,960
'No wonder it'll take
the rest of the year to master.

295
00:33:06,960 --> 00:33:10,960
'At least he has plenty of family
to practise with.

296
00:33:22,960 --> 00:33:25,960
'Though his older cousin

297
00:33:25,960 --> 00:33:27,960
'can get a little rough.

298
00:33:38,960 --> 00:33:42,960
'It's good preparation
for the future.

299
00:33:42,960 --> 00:33:47,960
'So far,
all he's known is an easy life.

300
00:33:49,640 --> 00:33:51,640
'But from this point on,

301
00:33:51,640 --> 00:33:54,960
'his home becomes drier.

302
00:33:58,960 --> 00:34:01,960
'The herd will weaken,

303
00:34:01,960 --> 00:34:04,960
'and the lions are waiting.

304
00:34:15,960 --> 00:34:17,960
'For the rest of the year,

305
00:34:17,960 --> 00:34:21,960
'the matriarch
must keep the herd from danger

306
00:34:21,960 --> 00:34:26,480
'and guide them
on a relentless search for water,

307
00:34:26,480 --> 00:34:30,960
'as rain becomes a distant memory.

308
00:34:36,800 --> 00:34:39,000
'Summer across
the Southern Hemisphere

309
00:34:39,000 --> 00:34:41,800
'is coming to an end.

310
00:34:42,960 --> 00:34:47,960
'After cradling their egg
for 55 days...

311
00:34:49,960 --> 00:34:52,960
'..the moment
the devoted king penguin parents

312
00:34:52,960 --> 00:34:54,960
'have waited for

313
00:34:54,960 --> 00:34:57,960
'has finally arrived.

314
00:34:57,960 --> 00:35:02,960
'It's time to welcome their chick
into the world.

315
00:35:05,960 --> 00:35:10,960
'The egg our king penguin parents
have been protecting since December

316
00:35:10,960 --> 00:35:12,960
'has finally hatched.

317
00:35:16,960 --> 00:35:20,640
'It will take the rest of the year
to raise her.

318
00:35:20,640 --> 00:35:23,960
'The longest parenthood of any bird.

319
00:35:26,960 --> 00:35:30,960
'Exhausted and unsteady...

320
00:35:31,960 --> 00:35:35,960
'..she's ready for her first meal.

321
00:35:48,960 --> 00:35:52,960
'She needs to build her strength
as quickly as she can...

322
00:35:56,960 --> 00:36:01,960
'..if she's to survive
the voracious predators...

323
00:36:04,960 --> 00:36:07,960
'..and worsening weather.

324
00:36:10,960 --> 00:36:14,960
'As the Southern Hemisphere
tilts away from the sun,

325
00:36:14,960 --> 00:36:18,960
'days will get shorter and tougher.

326
00:36:22,960 --> 00:36:24,960
'But in the north,

327
00:36:24,960 --> 00:36:28,960
'the first signs of spring
are fast approaching.

328
00:36:37,960 --> 00:36:41,960
'Warmth floods back
into Scandinavia's forests.

329
00:36:44,960 --> 00:36:48,960
'A very welcome change
for the resident red squirrels.

330
00:36:50,960 --> 00:36:54,960
'They don't hibernate
through winter.

331
00:36:54,960 --> 00:36:55,960
'But on a cold morning,

332
00:36:55,960 --> 00:36:59,480
'he's certainly not opposed
to a lie-in...'

333
00:37:03,960 --> 00:37:07,960
'..when he can get it.'

334
00:37:18,960 --> 00:37:21,320
'They just won't shut up.'

335
00:37:26,960 --> 00:37:28,480
'Fine!

336
00:37:28,480 --> 00:37:32,960
'Might as well make the most of
the longer days, now they're here.

337
00:37:47,800 --> 00:37:49,960
'If he's not sleeping,

338
00:37:49,960 --> 00:37:53,480
'he's thinking about his next meal.

339
00:37:57,000 --> 00:37:59,960
'This early in the year,

340
00:37:59,960 --> 00:38:02,960
'there's not much
but lichen and bark.

341
00:38:06,960 --> 00:38:10,960
'And too many fellow foragers

342
00:38:10,960 --> 00:38:12,960
'to contend with.

343
00:38:14,960 --> 00:38:17,960
'Including other reds.

344
00:38:17,960 --> 00:38:22,160
'Thankfully, he's, well,
squirreled away

345
00:38:22,160 --> 00:38:24,960
'his own secret stash.

346
00:38:26,320 --> 00:38:29,320
'In autumn, when the trees
were bursting with nuts,

347
00:38:29,320 --> 00:38:34,960
'he hid almost 3,000
across the forest.

348
00:38:35,960 --> 00:38:38,960
'He thought about his nuts so much,

349
00:38:38,960 --> 00:38:41,960
'his brain had to grow to cope.

350
00:38:43,960 --> 00:38:47,960
'A squirrel's hippocampus
expands by 15%

351
00:38:47,960 --> 00:38:50,960
'just to remember
where it cached them.

352
00:38:59,960 --> 00:39:01,960
'Yes!

353
00:39:10,480 --> 00:39:12,960
'Many of the other squirrels'
stockpiles

354
00:39:12,960 --> 00:39:15,960
'are empty this late in winter,

355
00:39:15,960 --> 00:39:19,960
'so they're on the lookout
for an easy meal.

356
00:39:29,960 --> 00:39:34,960
'Packed with protein
and rich in fats...

357
00:39:36,960 --> 00:39:40,960
'..these cheats
will do whatever they can

358
00:39:40,960 --> 00:39:43,800
'to get their hands

359
00:39:43,800 --> 00:39:45,960
'on his nuts.

360
00:40:50,960 --> 00:40:52,960
'He'll have to keep defending

361
00:40:52,960 --> 00:40:56,160
'his hard-earned stash
a little longer.

362
00:41:03,960 --> 00:41:06,640
'As winter comes to an end...

363
00:41:07,960 --> 00:41:12,000
'..more light falls across
the Northern Hemisphere.

364
00:41:12,000 --> 00:41:14,960
'Each day, like a tide,

365
00:41:14,960 --> 00:41:17,480
'the sun's life-giving rays

366
00:41:17,480 --> 00:41:21,960
'creep further and further
into the Arctic.

367
00:41:24,640 --> 00:41:26,960
'Until, finally...

368
00:41:28,640 --> 00:41:31,000
'..after a 112 days...

369
00:41:33,320 --> 00:41:38,960
'..the sun rises in Svalbard
once more.

370
00:42:06,640 --> 00:42:11,800
'The polar bear mother
has made it through the long winter.

371
00:42:16,160 --> 00:42:19,960
'And despite all its challenges...

372
00:42:22,960 --> 00:42:25,000
'..so has her cub.

373
00:42:35,960 --> 00:42:37,960
'They say raising a child

374
00:42:37,960 --> 00:42:40,960
'is one of the hardest things
you can do in life.

375
00:42:42,800 --> 00:42:44,480
'Letting them go...

376
00:42:45,960 --> 00:42:47,960
'..is even harder.

377
00:42:50,160 --> 00:42:53,960
'She must push him away

378
00:42:53,960 --> 00:42:56,960
'for his own good.

379
00:43:12,800 --> 00:43:15,960
'She's done all she can.

380
00:43:26,960 --> 00:43:28,960
'In his whole life,

381
00:43:28,960 --> 00:43:32,000
'he's never spent a day on his own.

382
00:43:35,960 --> 00:43:40,800
'Now, like all male polar bears,

383
00:43:40,800 --> 00:43:43,960
'apart from the briefest of moments,

384
00:43:43,960 --> 00:43:48,960
'he could roam
this frozen wilderness alone

385
00:43:48,960 --> 00:43:51,960
'for another 20 years.

386
00:43:56,960 --> 00:44:00,960
'If he remembers
what his mother taught him,

387
00:44:00,960 --> 00:44:02,960
'he might just survive.

388
00:44:06,960 --> 00:44:12,960
'Soon, the sun will hang in the sky
24 hours a day,

389
00:44:12,960 --> 00:44:17,960
'slowly melting away
this frozen world

390
00:44:17,960 --> 00:44:21,480
'with its unfathomable power.

391
00:44:22,960 --> 00:44:25,480
'In just one second,

392
00:44:25,480 --> 00:44:30,960
'our sun releases more energy
than all mankind has used

393
00:44:30,960 --> 00:44:32,960
'since the beginning of time.'

394
00:44:33,960 --> 00:44:36,320
Just let that sink in.

395
00:44:36,320 --> 00:44:40,960
From now on, it's going to
beat down on our northern pole

396
00:44:40,960 --> 00:44:44,960
for just a few extra minutes
each day.

397
00:44:45,960 --> 00:44:49,960
Unsurprisingly,
the effects are immense.

398
00:44:49,960 --> 00:44:54,960
Even now, its warming touch
is changing these icy valleys.

399
00:44:56,480 --> 00:45:00,960
And as the Northern Hemisphere
leans once more towards the sun,

400
00:45:00,960 --> 00:45:03,960
great change will sweep the globe.

401
00:45:03,960 --> 00:45:05,960
Spring is on the way,

402
00:45:05,960 --> 00:45:07,960
bringing with it new beginnings

403
00:45:07,960 --> 00:45:09,960
and great hardship

404
00:45:09,960 --> 00:45:13,960
for those who call this planet home.

405
00:45:30,640 --> 00:45:33,480
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