1  
00:00:07,866 --> 00:00:10,166  
在北美大陆的最北端...  
In the uppermost reaches of North America...  

2  
00:00:11,300 --> 00:00:13,600  
...有一片广袤的荒野——  
...there's a big, wild country --  

3  
00:00:16,500 --> 00:00:17,300  
加拿大。  
Canada.  

4  
00:00:19,066 --> 00:00:21,700  
这里有着地球上最大的完整森林。  
It has the largest intact forest on Earth.  

5  
00:00:24,666 --> 00:00:28,333  
超过两百万条河流、湖泊与溪流。  
More than two million rivers, lakes, and streams.  

6  
00:00:31,133 --> 00:00:33,066  
无垠的苔原。  
Vast swathes of tundra.  

7  
00:00:37,000 --> 00:00:38,933  
以及连绵不绝的崎岖海岸。  
And endless rugged shores.  

8  
00:00:44,733 --> 00:00:46,666  
生存于此并非易事。  
It can be a punishing place to live.  

9  
00:00:49,233 --> 00:00:51,766  
但这里也充满机遇...  
But it's also a land of opportunity...  

10  
00:00:53,833 --> 00:00:55,266  
...蕴藏着丰饶的资源。  
...with riches for the taking.  

11  
00:00:58,000 --> 00:01:00,333  
懂得如何行动与把握时机  
Knowing how and when to act  

12  
00:01:00,333 --> 00:01:03,133  
往往意味着生死之别。  
makes the difference between life and death.  

13  
00:01:05,233 --> 00:01:08,766  
若能适应，加拿大便是繁衍生息的乐土。  
Get it right, and Canada can be a place to thrive.  

14  
00:01:48,633 --> 00:01:50,066  
哈德逊湾，  
Hudson Bay,  

15  
00:01:50,066 --> 00:01:51,966  
北极圈的边缘地带。  
on the edge of the Arctic Circle.  

16  
00:01:54,966 --> 00:01:58,033  
这里栖息着加拿大最具代表性的海洋哺乳动物...  
Home to Canada's most iconic marine mammal...  

17  
00:02:00,666 --> 00:02:01,700  
...北极熊。  
...the polar bear.  

18  
00:02:09,366 --> 00:02:13,200  
夏日白昼漫长；  
It's summer and the days are long;  

19  
00:02:13,200 --> 00:02:14,266  
气温回暖。  
the air, warm.  

20  
00:02:18,933 --> 00:02:21,866  
对这群顶级掠食者而言，这是一年中最艰难的时期。  
This is the hardest time of year for these big predators.  

21  
00:02:28,366 --> 00:02:29,833  
没有海冰作为狩猎平台...  
There's no sea ice to hunt from...  

22  
00:02:31,200 --> 00:02:33,266  
...陆地上也鲜有食物。  
...and the land offers little to eat.  

23  
00:02:42,433 --> 00:02:43,866  
北极熊们每天流失  
The polar bears are losing more  

24  
00:02:43,866 --> 00:02:46,433  
超过两磅的脂肪。  
than two pounds of fat every day.  

25  
00:02:55,300 --> 00:02:56,333  
它们饥肠辘辘。  
They're hungry.  

26  
00:03:05,433 --> 00:03:07,266  
但北极熊记忆力超群。  
But polar bears have good memories.  

27  
00:03:14,266 --> 00:03:17,133  
这些猎手正前往河口  
These hunters are heading for a river mouth  

28  
00:03:17,133 --> 00:03:18,833  
它们知道在那里能找到食物。  
where they know they can find food.  

29  
00:03:32,200 --> 00:03:35,500  
而它们的时机把握得  
And they've got their timing just  

30  
00:03:32,200 --> 00:03:35,500  
恰到好处。  
right.  

31  
00:03:41,100 --> 00:03:43,600  
白鲸正成群抵达...  
Beluga whales are arriving...  

32  
00:03:48,166 --> 00:03:49,700  
...数量成千上万。  
...by the thousands.  

33  
00:03:55,766 --> 00:03:57,366  
它们来此养育幼崽  
They're here to raise their young  

34  
00:03:57,366 --> 00:04:00,033  
在河口温暖的浅水区。  
in the warm, shallow waters of the estuary.  

35  
00:04:15,166 --> 00:04:16,766  
但并非没有风险。  
But it's not without risk.  

36  
00:04:26,433 --> 00:04:29,100  
这两头雄性跃跃欲试。  
These two males are eager to hunt.  

37  
00:04:37,100 --> 00:04:39,066  
但策略截然不同。  
But they have very different approaches.  

38  
00:04:42,966 --> 00:04:47,933  
一头熊在精心挑选的岩石上静候时机。  
One bear bides his time on a carefully chosen rock.  

39  
00:04:50,566 --> 00:04:52,600  
另一头则直接追击白鲸。  
While the other goes after the belugas.  

40  
00:05:15,866 --> 00:05:17,433  
在开阔水域中，  
In the open water,  

41  
00:05:17,433 --> 00:05:19,566  
白鲸根本不可能被捕获。  
the belugas are impossible to catch.  

42  
00:05:23,800 --> 00:05:25,933  
它的战术显然行不通。  
His tactic clearly isn't working.  

43  
00:05:32,300 --> 00:05:33,400  
狩猎需要技巧...  
There's a trick to this...  

44  
00:05:34,600 --> 00:05:36,933  
...关键全在于潮汐。  
...and it's all down to the tides.  

45  
00:05:43,700 --> 00:05:45,600  
随着潮水上涨，  
As the waters rise,  

46  
00:05:45,600 --> 00:05:47,700  
白鲸游向更近岸处。  
the belugas come farther in shore.  

47  
00:05:51,666 --> 00:05:53,366  
对北极熊更为有利。  
Better for the polar bears.  

48  
00:06:02,600 --> 00:06:05,333  
只要游泳的那位别打草惊蛇。  
As long as the swimmer doesn't give the game away.  

49  
00:06:13,600 --> 00:06:16,366  
耐心熊的岩石已被淹没。  
The patient bear's rock is now submerged.  

50  
00:06:17,866 --> 00:06:19,233  
但它仍有机会。  
But he still has a chance.  

51  
00:06:40,300 --> 00:06:42,900  
岁月让这头老练的熊  
Experience has taught this old-timer  

52  
00:06:42,900 --> 00:06:44,433  
深谙高效狩猎之道。  
how to be an efficient hunter.  

53  
00:06:51,200 --> 00:06:53,600  
另一头熊还需多加学习。  
The other bear still has a lot to learn.  

54  
00:07:00,266 --> 00:07:02,000  
白鲸不会久留于此...  
The belugas won't stay here for long...  

55  
00:07:04,333 --> 00:07:07,333  
...因此北极熊必须在这短暂窗口期  
...so, the polar bears must feed as much as they can  

56  
00:07:07,333 --> 00:07:08,900  
尽可能多吃。  
in this narrow time window.  

57  
00:07:14,400 --> 00:07:16,800  
吃饱喝足后，  
And, with bellies full,  

58  
00:07:16,800 --> 00:07:19,000  
甚至还有嬉戏的时间。  
there's even a bit of time for play.  

59  
00:07:29,366 --> 00:07:32,800  
加拿大是片广袤的土地  
Canada is a vast land mass  

60  
00:07:32,800 --> 00:07:36,333  
覆盖北美近四百万平方英里...  
covering nearly four million square miles of North America...  

61  
00:07:38,900 --> 00:07:41,800  
...其中一半是无树的苔原，  
...and half of it is treeless tundra,  

62  
00:07:41,800 --> 00:07:43,866  
崎岖而荒凉。  
rugged and exposed.  

63  
00:07:46,100 --> 00:07:49,133  
在此生存需要智慧...  
To survive here, you need to be smart...  

64  
00:07:51,633 --> 00:07:53,233  
...比如北极狐。  
...like the arctic fox.  

65  
00:07:57,333 --> 00:08:00,166  
这只雄性为伴侣捕到一只旅鼠。  
This male has caught a lemming for his mate.  

66  
00:08:03,500 --> 00:08:05,300  
它需要帮手...  
She needs his help...  

67  
00:08:08,033 --> 00:08:09,700  
...因为它要照顾幼崽。  
...as she's got young to look after.  

68  
00:08:17,100 --> 00:08:18,066  
双亲都  
Both parents  

69  
00:08:18,066 --> 00:08:19,466  
肩负重任...  
have a lot on their plate...  

70  
00:08:21,300 --> 00:08:25,100  
...要养育六只胃口旺盛的吵闹幼崽。  
...raising six boisterous kits with big appetites.  

71  
00:08:43,600 --> 00:08:44,800  
除此之外，  
On top of that,  

72  
00:08:44,800 --> 00:08:46,666  
父母还需储备足够食物  
the parents must gather enough food  

73  
00:08:46,666 --> 00:08:48,600  
助它们度过寒冬。  
to help them through the winter.  

74  
00:08:50,000 --> 00:08:53,166  
幸运的是，一个大好机会正向它们靠近...  
Luckily, there's a big opportunity heading their way...  

75  
00:08:58,866 --> 00:08:59,800  
...雪雁。  
...snow geese.  

76  
00:09:05,700 --> 00:09:09,333  
每年夏季，成千上万的雪雁来此繁衍后代。  
Every summer, thousands of them come here to raise their young.  

77  
00:09:23,000 --> 00:09:26,100  
每只母雁会产下一窝蛋，  
Each mother goose lays a clutch of eggs,  

78  
00:09:26,100 --> 00:09:28,300  
孵化期持续三周。  
which she'll sit on for three weeks.  

79  
00:09:31,066 --> 00:09:33,833  
这些蛋正是狐狸的目标。  
These eggs are what the foxes are after.  

80  
00:09:37,566 --> 00:09:40,766  
它们要在孵化前尽可能多地收集。  
They want to gather as many as they can before they hatch.  

81  
00:09:49,666 --> 00:09:52,933  
要躲过暴躁的成鸟并非易事。  
It's not easy getting past the feisty parents.  

82  
00:09:58,966 --> 00:10:03,266  
但狐狸们意志坚定，每天能收集多达60枚蛋。  
But the foxes are determined, and gather up to 60 eggs a day.  

83  
00:10:07,833 --> 00:10:09,366  
每偷到一枚蛋，  
Each one they steal,  

84  
00:10:09,366 --> 00:10:11,000  
它们就埋入冻土。  
they bury in the frozen earth.  

85  
00:10:14,433 --> 00:10:16,666  
这是储存食物的绝佳方式，  
It's a great way to store food,  

86  
00:10:16,666 --> 00:10:18,700  
能为接下来的匮乏月份做准备。  
as it'll keep for the leaner months ahead.  

87  
00:10:37,433 --> 00:10:39,733  
当雏鸟开始破壳，  
Once the hatching starts,  

88  
00:10:39,733 --> 00:10:41,933  
狐狸又迎来了新机遇...  
there's another opportunity for the foxes...  

89  
00:10:43,866 --> 00:10:46,333  
...恰逢幼崽需要固体食物之时。  
...just as the kits are ready for solid food.  

90  
00:10:58,833 --> 00:11:00,333  
但时机转瞬即逝。  
But it doesn't last long.  

91  
00:11:02,366 --> 00:11:04,466  
破壳几小时内，  
Within hours of hatching,  

92  
00:11:04,466 --> 00:11:07,100  
雁宝宝们就会被带到安全水域。  
the goslings are led to the safety of water.  

93  
00:11:14,200 --> 00:11:17,900  
大多数雪雁能安然度过夏季，  
Most of the snow geese will make it through the summer,  

94  
00:11:17,900 --> 00:11:19,933  
直至南迁之时。  
until it's time to journey south.  

95  
00:11:28,233 --> 00:11:30,700  
虽然狐狸无法离开，  
Though the foxes can't leave,  

96  
00:11:30,700 --> 00:11:32,966  
它们已为严冬做足准备。  
they're well-prepared for the tougher times ahead.  

97  
00:11:36,833 --> 00:11:39,700  
狐妈妈甚至找到了最丰盛的残羹盛宴。  
Mom even scavenges the biggest feast of all.  

98  
00:11:49,566 --> 00:11:53,500  
全家饱餐一顿；储藏室也满满当当。  
The family is fed; and the larder, full.  

99  
00:12:08,566 --> 00:12:13,066  
加拿大北部荒野的机遇可能极为丰厚...  
Opportunities in Canada's wild north can be immense...  

100  
00:12:15,800 --> 00:12:18,200  
...但时机窗口往往短暂  
...but the windows are often short  

101  
00:12:18,200 --> 00:12:19,866  
且需精准把握。  
and require precision timing.  

102  
00:12:29,866 --> 00:12:32,533  
东海岸的新斯科舍省，  
Nova Scotia, on the East Coast,  

103  
00:12:32,533 --> 00:12:34,966  
拥有地球上最极端的潮汐。  
has the most extreme tides on Earth.  

104  
00:12:39,200 --> 00:12:41,266  
在芬迪湾，  
Here, in the Bay of Fundy,  

105  
00:12:41,266 --> 00:12:47,066  
每天有1760亿吨海水两度涨落。  
176 billion tons of water moves in and out twice a day.  

106  
00:12:50,600 --> 00:12:54,233  
超过全球所有河流流量的总和。  
That's more than the combined flow of all the world's rivers.  

107  
00:12:58,266 --> 00:12:59,833  
这片泥滩中栖息着  
Living in these mudflats  

108  
00:12:59,833 --> 00:13:03,333  
仅在夏末浮出水面的生物。  
are creatures that only come to the surface in late summer.  

109  
00:13:11,833 --> 00:13:14,166  
泥虾。  
Mud shrimps.  

110  
00:13:14,166 --> 00:13:15,633  
正外出寻找配偶。  
Out looking for mates.  

111  
00:13:22,266 --> 00:13:24,066  
但在岸上，  
But up here,  

112  
00:13:24,066 --> 00:13:28,766  
追求异性的行为让它们暴露无遗...  
the pursuit of the opposite sex leaves them very exposed...  

113  
00:13:32,866 --> 00:13:34,466  
...面临年度大劫。  
...to an annual onslaught.  

114  
00:13:39,133 --> 00:13:41,233  
半蹼滨鹬。  
Semipalmated sandpipers.  

115  
00:13:43,000 --> 00:13:44,800  
足足二十万只。  
Two hundred thousand of them.  

116  
00:13:48,633 --> 00:13:51,266  
这些鸟儿正在进行伟大迁徙，  
These birds are on a huge migration  

117  
00:13:51,266 --> 00:13:53,733  
从加拿大北极圈飞往南美洲。  
from Canada's arctic to South America.  

118  
00:14:01,866 --> 00:14:04,400  
它们在此停留以泥虾为食。  
They stop here to feast on the shrimps.  

119  
00:14:08,900 --> 00:14:12,033  
体重必须增加一倍才能继续旅程。  
And they can't move on until they've doubled in weight.  

120  
00:14:17,000 --> 00:14:20,966  
每只小鸟要捕食多达两万只泥虾。  
Each small bird must harvest up to 20,000 shrimp.  

121  
00:14:22,700 --> 00:14:24,233  
在一个潮汐周期内完成。  
In a single tidal cycle.  

122  
00:14:32,533 --> 00:14:33,866  
但随着涨潮将滨鹬们  
But as the incoming tide  

123  
00:14:33,866 --> 00:14:37,133  
逐渐逼回海滩高处，  
pushes the sandpipers back up the beach,  

124  
00:14:37,133 --> 00:14:39,033  
它们的活动空间越来越小。  
they have less room for maneuver.  

125  
00:14:41,866 --> 00:14:44,966  
成了致命猎手的活靶子。  
Easy targets for a deadly predator.  

126  
00:14:57,866 --> 00:14:59,700  
游隼。  
The peregrine falcon.  

127  
00:14:59,700 --> 00:15:01,766  
地球上速度最快的生物。  
The fastest creature on Earth.  

128  
00:15:16,333 --> 00:15:20,100  
鸟群集体行动试图迷惑猎手。  
The flock moves as one, trying to confuse the hunter.  

129  
00:15:38,800 --> 00:15:40,366  
它们躲过了第一轮攻击。  
They dodge the first strike.  

130  
00:15:44,600 --> 00:15:48,400  
但天敌正攀升高度准备发动更迅猛的袭击。  
But their nemesis gains height for an even faster attack.

131  
00:16:06,133 --> 00:16:07,466  
一只虚弱的滨鹬受伤了。  
A weak one is injured.  

132  
00:16:10,000 --> 00:16:10,800  
被擒获。  
And taken.  

133  
00:16:16,133 --> 00:16:18,833  
游隼是永恒的威胁。  
The peregrine is a constant menace.  

134  
00:16:22,000 --> 00:16:25,533  
但经过十天的充足进食，  
But after 10 days of good feeding,  

135  
00:16:25,533 --> 00:16:28,233  
滨鹬们已增重足够，  
the sandpipers have put on enough weight  

136  
00:16:28,233 --> 00:16:30,566  
得以继续南迁的史诗之旅。  
to continue their epic journey south.  

137  
00:16:41,300 --> 00:16:46,566  
加拿大拥有全球最长的海岸线——  
Canada has the longest coastline of any country on Earth --  

138  
00:16:46,566 --> 00:16:49,533  
逾15万英里。  
more than 150,000 miles.  

139  
00:16:52,033 --> 00:16:53,800  
而在其西部边缘...  
And, on its western margins...  

140  
00:16:55,000 --> 00:16:57,033  
...陆地与太平洋相接处...  
...where the land meets the Pacific Ocean...  

141  
00:16:58,033 --> 00:17:02,566  
...有一片被清凉富饶海水滋养的奇幻世界。  
...there's a magical world nourished by cool, rich water.  

142  
00:17:17,166 --> 00:17:20,000  
沿着不列颠哥伦比亚省的海岸线，  
Along the coastline of British Columbia  

143  
00:17:20,000 --> 00:17:21,866  
生长着巨型海藻森林。  
are giant forests of kelp.  

144  
00:17:25,600 --> 00:17:29,166  
这种藻类每天能生长两英尺...  
This algal seaweed can grow up to two feet a day...  

145  
00:17:31,966 --> 00:17:36,100  
...特殊的气囊将它们托向夏日阳光。  
...its special air sacs lifting it towards the summer sunshine.  

146  
00:17:46,566 --> 00:17:49,933  
海獭完美适应了这片水下森林。  
Sea otters are well-adapted to this aquatic forest.  

147  
00:17:54,900 --> 00:17:56,866  
它们将自己系在海藻上，  
They tether themselves to the kelp,  

148  
00:17:56,866 --> 00:18:00,200  
这样打盹时就不会漂走。  
as it allows them to snooze without drifting away.  

149  
00:18:07,300 --> 00:18:09,833  
这些群居动物会聚集成  
These social animals float together  

150  
00:18:09,833 --> 00:18:12,133  
多达百只的漂浮群落。  
in rafts up to 100 strong.  

151  
00:18:22,433 --> 00:18:25,000  
夏季是生育高峰季。  
Summer is peak pupping season.  

152  
00:18:35,300 --> 00:18:37,400  
为给幼崽保暖，  
To keep their babies warm,  

153  
00:18:37,400 --> 00:18:39,433  
母亲们会让宝宝趴在肚皮上...  
the mothers balance them on their tummies...  

154  
00:18:41,300 --> 00:18:43,500  
...并向它们浓密的毛发吹入空气。  
...and blow air into their thick fur.  

155  
00:18:58,000 --> 00:19:02,300  
在寒冷水域中，海獭消耗大量热量，  
Sea otters burn so many calories in these chilly waters,  

156  
00:19:02,300 --> 00:19:05,100  
食量需达到  
they need to eat three times more food  

157  
00:19:05,100 --> 00:19:07,066  
同等体型陆地哺乳动物的三倍。  
than similar-sized land mammals.  

158  
00:19:12,300 --> 00:19:15,800  
这头雄性正在寻找终极美餐。  
This male is on the hunt for the ultimate meal.  

159  
00:19:22,833 --> 00:19:24,533  
找到猎物是一回事。  
Finding it is one thing.  

160  
00:19:25,833 --> 00:19:27,700  
挖出猎物是另一回事。  
Extracting it is another.  

161  
00:19:29,566 --> 00:19:32,033  
它深埋在三英尺多的沙层下。  
It's more than three feet under the sand.  

162  
00:19:39,833 --> 00:19:43,233  
而毛发中的空气不断将它向上拉扯。  
And the air in his fur is constantly pulling him upwards.  

163  
00:19:55,233 --> 00:19:56,666  
象拔蚌——  
A geoduck --  

164  
00:19:56,666 --> 00:19:59,400  
世界上最大的钻穴蛤类之一。  
one of the world's largest burrowing clams.  

165  
00:20:11,266 --> 00:20:13,500  
海獭群居以保安全。  
Sea otters stick together for safety.  

166  
00:20:15,333 --> 00:20:18,000  
在加拿大这里，它们必须保持警觉...  
And, here in Canada, they need to stay alert...  

167  
00:20:21,500 --> 00:20:25,233  
...因为海岸边潜行着古老的敌人。  
...for on these shores stalks an age-old enemy.  

168  
00:20:30,933 --> 00:20:32,833  
海狼——  
The sea wolf --  

169  
00:20:32,833 --> 00:20:34,900  
专业的海岸猎手。  
a specialist coastal hunter.  

170  
00:20:49,500 --> 00:20:52,933  
但这群狼今日的目标并非海獭。  
But this pack isn't looking for otters today.  

171  
00:21:01,766 --> 00:21:04,966  
更大的机遇正向它们涌来。  
There's a far bigger opportunity coming their way.  

172  
00:21:16,733 --> 00:21:19,133  
太平洋鲑鱼，  
Pacific salmon,  

173  
00:21:19,133 --> 00:21:20,500  
浩荡的鱼群。  
great shoals of them.  

174  
00:21:25,300 --> 00:21:28,533  
这些粉红鲑是五种洄游至  
These pink salmon are one of the five species arriving  

175  
00:21:28,533 --> 00:21:29,900  
加拿大西海岸的鲑鱼之一。  
on the West Coast of Canada.  

176  
00:21:33,433 --> 00:21:36,966  
经过数年在海洋中的觅食，它们正值壮年，  
After years of feeding at sea, they're in their prime  

177  
00:21:36,966 --> 00:21:39,200  
准备洄游内陆产卵。  
and ready to migrate inland to spawn.  

178  
00:21:44,000 --> 00:21:46,266  
但它们在溯河而上前，  
But they need conditions to be just right  

179  
00:21:46,266 --> 00:21:47,333  
需要条件恰到好处。  
before they swim upriver.  

180  
00:21:58,866 --> 00:22:01,166  
在鲑鱼等待期间，  
And, while the salmon wait,  

181  
00:22:01,166 --> 00:22:03,233  
它们成了狼群的活靶子。  
they're easy targets for the wolves.  

182  
00:22:07,800 --> 00:22:09,533  
猎物多到应接不暇。  
There's more than enough to choose from.  

183  
00:22:31,166 --> 00:22:34,466  
每匹狼每小时能捕获多达30条鲑鱼。  
Each wolf can catch up to 30 salmon an hour.  

184  
00:22:39,100 --> 00:22:41,133  
但这些鱼有个问题。  
But there's a problem with these fish.  

185  
00:22:44,000 --> 00:22:47,833  
鲑鱼肉中寄生虫密布，  
The salmon's flesh is riddled with parasites,  

186  
00:22:47,833 --> 00:22:49,766  
对狼群可能致命。  
which could be lethal for the wolves.  

187  
00:22:52,466 --> 00:22:53,866  
但它们仍持续捕猎。  
Yet they keep on hunting.  

188  
00:22:59,500 --> 00:23:01,400  
这些狼自有策略。  
These wolves have a strategy.  

189  
00:23:08,833 --> 00:23:10,166  
它们将鲑鱼摊开...  
They lay the salmon out...  

190  
00:23:15,233 --> 00:23:17,600  
...任由食腐动物前来享用。  
...letting the scavengers come and feed.  

191  
00:23:29,600 --> 00:23:32,466  
乌鸦与白头海雕等鸟类  
Birds, like crows and bald eagles  

192  
00:23:32,466 --> 00:23:34,266  
能安全食用鱼肉，  
are able to eat the flesh  

193  
00:23:34,266 --> 00:23:36,500  
因不受寄生虫影响。  
because they're unaffected by the parasites.  

194  
00:23:39,833 --> 00:23:43,166  
狼群则享用富含营养的鱼皮和鱼头，  
The wolves are left with the nutritious skin and head,  

195  
00:23:43,166 --> 00:23:44,700  
这些对它们无害。  
which they can eat safely.  

196  
00:23:52,666 --> 00:23:55,233  
这种合作是聪明的解决方案。  
This partnership is a clever solution.  

197  
00:23:59,633 --> 00:24:02,700  
这份季节性馈赠令各方受益。  
Everyone benefits from this seasonal bounty.  

198  
00:24:20,000 --> 00:24:23,466  
随着不列颠哥伦比亚省进入秋季，  
As autumn sets in across British Columbia,  

199  
00:24:23,466 --> 00:24:25,233  
降雨越来越频繁...  
more and more rain falls...  

200  
00:24:27,133 --> 00:24:28,633  
...导致河水上涨。  
...causing rivers to rise.  

201  
00:24:31,700 --> 00:24:35,733  
鲑鱼即将开始它们溯河而上的马拉松之旅。  
The salmon are ready to begin their marathon journey upriver.  

202  
00:25:21,300 --> 00:25:24,000  
向内陆行进数百英里  
Traveling hundreds of miles inland  

203  
00:25:24,000 --> 00:25:26,033  
是巨大的耐力考验。  
is a huge feat of endurance.  

204  
00:25:28,233 --> 00:25:31,233  
但鲑鱼终将抵达产卵地。  
But the salmon finally reach their spawning grounds.  

205  
00:25:36,800 --> 00:25:39,966  
它们结对产下数千枚卵。  
They pair up and lay thousands of eggs.  

206  
00:25:46,533 --> 00:25:48,600  
仅10%能成功孵化。  
Only 10% will go on to hatch.  

207  
00:25:50,266 --> 00:25:52,633  
其余则成为河乌等生物  
The rest are an important source of food  

208  
00:25:52,633 --> 00:25:54,133  
的重要食物来源。  
for creatures like the dipper.  

209  
00:26:06,300 --> 00:26:08,000  
在加拿大北部荒野...  
In Canada's wild north...  

210  
00:26:09,566 --> 00:26:12,400  
...海洋滋养着遥远的内陆生命。  
...the sea nourishes life far inland.  

211  
00:26:23,733 --> 00:26:26,833  
产卵是鲑鱼最后的使命。  
Spawning is the salmon's final act.  

212  
00:26:33,266 --> 00:26:36,166  
黑熊会带走鲑鱼，无论生死。  
Black bears take the salmon, dead or alive.  

213  
00:26:38,966 --> 00:26:41,933  
它们需在冬眠前增重一倍。  
They need to double in weight before hibernation.  

214  
00:26:52,400 --> 00:26:55,400  
熊群还会将部分鲑鱼带入森林。  
The bears also carry some salmon into the forest.  

215  
00:26:59,066 --> 00:27:01,066  
常常多得吃不完。  
Often, more than they can manage.  

216  
00:27:11,800 --> 00:27:12,700  
但不会浪费。  
But they're not wasted.  

217  
00:27:15,233 --> 00:27:18,466  
腐烂的鱼身反哺大地...  
Their rotting bodies help feed the earth...  

218  
00:27:20,533 --> 00:27:23,033  
...使得沿岸树木  
...allowing the trees along these riverbanks  

219  
00:27:23,033 --> 00:27:24,800  
生长速度提升30%。  
to grow 30% faster.  

220  
00:27:31,166 --> 00:27:34,933  
这片森林被称为大熊雨林...  
This forest is called the Great Bear Rainforest...  

221  
00:27:36,133 --> 00:27:39,033  
...但成就其伟大的正是鲑鱼。  
...but it's the salmon that make it great.  

222  
00:27:47,633 --> 00:27:50,700  
随着季节更迭、白昼缩短...  
As the seasons progress and the days shorten...  

223  
00:27:51,866 --> 00:27:53,866  
...那些重要的机遇窗口  
...the big windows of opportunity  

224  
00:27:53,866 --> 00:27:55,466  
正逐渐关闭。  
are starting to close.  

225  
00:27:59,666 --> 00:28:03,266  
加拿大正为即将到来的严寒做准备。  
Canada is bracing itself for what's to come.  

226  
00:28:07,166 --> 00:28:09,566  
少有环境比横跨加拿大的  
And there are few environments tougher  

227  
00:28:09,566 --> 00:28:12,133  
北方大森林更为严酷，  
than the great boreal forest  

228  
00:28:12,133 --> 00:28:15,400  
它西起育空地区，  
that stretches right across Canada,  

229  
00:28:15,400 --> 00:28:18,800  
东至纽芬兰。  
from the Yukon in the west to Newfoundland in the east.  

230  
00:28:21,966 --> 00:28:24,300  
面积超百万平方英里。  
Over a million square miles of it.  

231  
00:28:27,033 --> 00:28:30,633  
这是地球上最完整的原始森林。  
The largest intact forest on the planet.  

232  
00:28:46,600 --> 00:28:50,633  
冬季来临，机遇寥寥。  
As winter sets in, opportunities are slim.  

233  
00:28:57,733 --> 00:29:00,300  
但把握机遇意味着  
Yet taking them means the difference  

234  
00:29:00,300 --> 00:29:02,466  
生死之别。  
between life and death.  

235  
00:29:15,000 --> 00:29:17,166  
在育空地区，  
Here, in the Yukon,  

236  
00:29:17,166 --> 00:29:19,433  
没有大规模迁徙到来...  
there are no great migrations arriving...  

237  
00:29:20,933 --> 00:29:22,500  
...没有天降食物。  
...no windfall of food.  

238  
00:29:26,866 --> 00:29:29,133  
唯有无尽的严寒与冰雪。  
Just relentless cold and snow.  

239  
00:29:39,233 --> 00:29:41,300  
这样的日子将持续数月。  
It'll be like this for months.  

240  
00:29:47,000 --> 00:29:50,933  
雪改变了整个地貌的生态。  
Snow changes the whole dynamic of the landscape.  

241  
00:29:54,033 --> 00:29:56,066  
雪质随气温与湿度  
Its texture is constantly changing  

242  
00:29:56,066 --> 00:29:58,666  
不断变化。  
with the air temperature and moisture levels.  

243  
00:30:06,333 --> 00:30:08,566  
今日雪层坚实。  
Today, it's firm.  

244  
00:30:11,500 --> 00:30:15,566  
正是潜行猎手的理想条件。  
Ideal conditions for a stealthy hunter.  

245  
00:30:25,266 --> 00:30:29,500  
这种猫科动物的脚掌构造完美，  
A cat whose paws are so perfectly shaped,  

246  
00:30:29,500 --> 00:30:32,366  
行走时几乎无声无息。  
it can walk in almost total silence.  

247  
00:30:37,266 --> 00:30:38,600  
加拿大猞猁。  
The Canada lynx.  

248  
00:30:46,600 --> 00:30:48,133  
它的目标正是这个。  
And this is what he's after.  

249  
00:30:50,133 --> 00:30:51,266  
雪靴兔。  
A snowshoe hare.  

250  
00:30:59,866 --> 00:31:01,733  
要想成功捕猎...  
To stand a chance of catching it...  

251  
00:31:03,200 --> 00:31:05,200  
...它必须接近到30英尺内。  
...he must get within 30 feet.  

252  
00:31:36,566 --> 00:31:40,366  
雪靴兔拥有绝佳伪装，  
The hare is brilliantly camouflaged,  

253  
00:31:40,366 --> 00:31:42,500  
听觉敏锐，  
with acute hearing,  

254  
00:31:42,500 --> 00:31:44,733  
触须灵敏...  
sensitive whiskers...  

255  
00:31:44,733 --> 00:31:46,733  
视野宽广。  
and a wide field of view.  

256  
00:33:01,133 --> 00:33:04,666  
加拿大猞猁依赖雪靴兔为生。  
The Canada lynx is dependent on snowshoe hares.  

257  
00:33:06,600 --> 00:33:09,733  
当兔群数量下降，猞猁就陷入困境。  
When hare numbers are down, lynx struggle.  

258  
00:33:12,533 --> 00:33:15,933  
当兔群繁盛时，猞猁便兴旺发达。  
And when they are up, the lynx really prosper.  

259  
00:33:21,733 --> 00:33:26,466  
加拿大北部荒野是片盛衰无常的土地，  
Canada's wild north is a land of boom and bust  

260  
00:33:26,466 --> 00:33:29,066  
而今年恰逢丰年。  
and this year is a good year.

261  
00:33:33,500 --> 00:33:36,966  
这个养育着四只健康幼崽的猞猁家庭，  
This family, with four healthy kittens,  

262  
00:33:36,966 --> 00:33:38,333  
便是明证。  
is testament to that.  

263  
00:33:48,766 --> 00:33:52,066  
北方森林看似荒凉空旷...  
The boreal forest may seem sparse and empty...  

264  
00:33:53,866 --> 00:33:55,800  
...实则食物丰饶，  
...but there is plenty of food here,  

265  
00:33:55,800 --> 00:33:57,733  
只要知晓觅食之道。  
if you know where to look.  

266  
00:34:00,300 --> 00:34:03,733  
多数食物隐藏在  
Much of it is concealed in a secret world  

267  
00:34:03,733 --> 00:34:05,433  
积雪之下的秘境中。  
beneath the surface of the snow.  

268  
00:34:13,333 --> 00:34:15,233  
认识下红背田鼠。  
Meet the red-backed vole.  

269  
00:34:19,600 --> 00:34:23,600  
它利用地道网络搜寻食物，  
He uses his network of tunnels to find his food,  

270  
00:34:23,600 --> 00:34:26,166  
比如树皮、种子和浆果。  
such as bark, seeds, and berries.  

271  
00:34:34,600 --> 00:34:40,533  
但有位猎手能洞悉它的每步行动。  
But there's one creature that can hear his every move.  

272  
00:34:45,133 --> 00:34:46,800  
乌林鸮。  
The great grey owl.  

273  
00:34:49,166 --> 00:34:51,866  
它是全球体型最大的猫头鹰。  
She's the largest of her kind in the world.  

274  
00:34:54,500 --> 00:34:56,833  
对田鼠有着巨大胃口。  
With a big appetite for voles.  

275  
00:35:02,666 --> 00:35:05,600  
眼周的羽毛圆盘  
The circle of feathers around her eyes  

276  
00:35:05,600 --> 00:35:08,533  
能将最微弱的声音导入耳中。  
directs the faintest sounds to her ears.  

277  
00:35:14,033 --> 00:35:15,233  
积雪之下，  
Under the snow,  

278  
00:35:15,233 --> 00:35:17,600  
田鼠尽可能保持安静。  
the vole is as quiet as possible.  

279  
00:35:26,733 --> 00:35:28,366  
但今天它运气不佳。  
But it's not his lucky day.  

280  
00:35:31,466 --> 00:35:34,500  
一只短尾鼬嗅到了它的气味。  
A short-tailed weasel has picked up his scent.  

281  
00:35:37,433 --> 00:35:38,500  
它必须逃离。  
He's got to get out.  

282  
00:36:27,900 --> 00:36:31,833  
微弱的脚步声为这位无声杀手指明了方向。  
His tiny footsteps are a beacon to this silent killer.  

283  
00:36:52,633 --> 00:36:55,333  
这次乌林鸮错失良机。  
This time, the owl misses her chance.  

284  
00:36:58,533 --> 00:37:00,566  
田鼠得以幸存。  
The vole gets to live another day.  

285  
00:37:17,266 --> 00:37:22,000  
夜幕下的加拿大北方森林宛如异界。  
At night, Canada's boreal forest becomes a very different world.  

286  
00:37:28,933 --> 00:37:33,033  
气温骤降至零下40华氏度。  
Temperatures plunge to -40° Fahrenheit.  

287  
00:37:36,300 --> 00:37:38,800  
显然不宜外出觅食。  
Surely, not the best time to be out foraging.  

288  
00:37:42,566 --> 00:37:45,400  
但有种生物却反其道而行。  
But there is an unusual creature who is.  

289  
00:37:51,533 --> 00:37:52,833  
一种松鼠。  
A type of squirrel.  

290  
00:37:56,900 --> 00:38:00,333  
严寒迫使它无法久留户外。  
Because it's so cold, she can't stay out for long.  

291  
00:38:04,200 --> 00:38:06,900  
必须快速找到食物。  
That means she needs to find food, fast.  

292  
00:38:15,800 --> 00:38:19,100  
为此它掌握着特殊技能。  
To achieve this, she's got a special trick.  

293  
00:38:28,433 --> 00:38:31,500  
这是北美飞鼠。  
This is a southern flying squirrel.  

294  
00:38:41,333 --> 00:38:43,800  
滑翔助其快速移动  
Gliding helps her get around quickly  

295  
00:38:43,800 --> 00:38:46,200  
并减少暴露于严寒的时间。  
and minimizes her exposure to the cold.  

296  
00:38:57,700 --> 00:38:59,133  
今夜行动结束。  
Time is up for tonight.  

297  
00:39:04,933 --> 00:39:07,300  
树巢提供些许庇护...  
This tree nest provides some shelter...  

298  
00:39:08,933 --> 00:39:11,300  
...但巢内依然  
...but it's still incredibly  

299  
00:39:08,933 --> 00:39:11,300  
严寒刺骨。  
cold inside.  

300  
00:39:18,700 --> 00:39:21,366  
幸好来了位同伴。  
Fortunately, someone else has arrived.  

301  
00:39:37,166 --> 00:39:38,266  
暖和些了。  
That's a bit warmer.  

302  
00:39:43,133 --> 00:39:46,500  
两只作伴挺好，不过在这里，  
Two is good company, but here,  

303  
00:39:46,500 --> 00:39:47,566  
来者不拒。  
everyone is welcome.  

304  
00:39:59,266 --> 00:40:02,466  
许多无亲缘关系的飞鼠共居一巢。  
Many unrelated individuals share the same nest.  

305  
00:40:09,233 --> 00:40:12,600  
相拥取暖度过寒夜。  
Cuddles enough to get them through the night.  

306  
00:40:24,200 --> 00:40:28,200  
在加拿大北方森林的参天林木间，  
Among the great stands of Canada's boreal forest,  

307  
00:40:28,200 --> 00:40:30,133  
积雪覆盖之下，  
hidden beneath the snow,  

308  
00:40:30,133 --> 00:40:32,700  
藏着60万座冰封湖泊。  
are 600,000 icy lakes.  

309  
00:40:37,633 --> 00:40:41,633  
这些开阔地带往往能左右  
These big, open spaces can make all  

310  
00:40:37,633 --> 00:40:41,633  
两个古老敌手间  
the difference  

311  
00:40:41,633 --> 00:40:45,233  
永恒较量的胜负。  
in the constant battles between two ancient enemies.  

312  
00:40:53,666 --> 00:40:57,133  
加拿大狼是聪慧而灵活的猎手。  
Canada wolves are very smart and adaptable hunters.  

313  
00:41:01,166 --> 00:41:04,066  
它们深谙如何利用冬季环境  
They know how to make the most of this environment  

314  
00:41:04,066 --> 00:41:07,233  
并将其转化为优势。  
during winter, and use it to their advantage.  

315  
00:41:13,066 --> 00:41:15,633  
驯鹿是它们最爱的猎物之一。  
One of their favorite prey is caribou.  

316  
00:41:21,833 --> 00:41:24,700  
驯鹿以群体力量自保，  
They find strength in numbers  

317  
00:41:24,700 --> 00:41:27,233  
常为觅食而迁徙。  
and are often on the move, looking for food.  

318  
00:41:36,933 --> 00:41:39,766  
狼群如影随形，  
The wolves constantly shadow them,  

319  
00:41:39,766 --> 00:41:41,900  
静待时机。  
waiting for any opportunity.  

320  
00:41:50,166 --> 00:41:51,700  
在冰封湖面上，  
Out on the frozen lakes,  

321  
00:41:51,700 --> 00:41:54,300  
坚实的地表让驯鹿  
where the ground is firm underfoot,  

322  
00:41:54,300 --> 00:41:57,966  
能凭速度甩开狼群。  
the caribou have the advantage, as they can outrun the wolves.  

323  
00:42:11,366 --> 00:42:12,933  
猎手们暂时败退。  
The hunters are beaten.  

324  
00:42:12,933 --> 00:42:13,733  
仅限此刻。  
For now.  

325  
00:42:25,000 --> 00:42:26,500  
较量转入对峙阶段。  
It becomes a waiting game.  

326  
00:42:35,133 --> 00:42:38,266  
但狼群知道驯鹿不可能永远停留。  
But the wolves know the caribou can't stay here forever.  

327  
00:42:48,066 --> 00:42:49,500  
驯鹿需要进食...  
The caribou need to eat...  

328  
00:42:50,433 --> 00:42:52,966  
...而唯一能找到食物的地点  
...and the only place they can find food  

329  
00:42:52,966 --> 00:42:55,366  
是湖畔的森林...  
is in the forest, on the edge of the lake...  

330  
00:42:58,433 --> 00:43:00,900  
...那里积雪更深。  
...where the snow is a lot deeper.  

331  
00:43:17,966 --> 00:43:19,933  
在这险恶地形中，  
In this difficult terrain,  

332  
00:43:19,933 --> 00:43:22,233  
驯鹿的处境  
the caribou are far  

333  
00:43:19,933 --> 00:43:22,233  
危险得多。  
more vulnerable.  

334  
00:43:27,566 --> 00:43:28,900  
它们必须动作迅速...  
They must work fast...  

335  
00:43:30,333 --> 00:43:31,433  
...挖掘地衣...  
...digging for lichens...  

336  
00:43:34,166 --> 00:43:35,533  
...同时保持高度警觉。  
...and keep on high alert.  

337  
00:43:49,266 --> 00:43:50,566  
狼群来了。  
The wolves are coming.  

338  
00:44:10,400 --> 00:44:12,000  
借助森林掩护...  
Using the forest as cover...  

339  
00:44:14,133 --> 00:44:16,100  
...它们逐步逼近。  
...they edge ever closer.  

340  
00:44:23,366 --> 00:44:25,333  
最终完成合围。  
Until they've surrounded the herd.  

341  
00:44:47,933 --> 00:44:50,733  
狼群需将驯鹿困在深雪区...  
The wolves need to keep the caribou in the deep snow...  

342  
00:44:53,166 --> 00:44:55,000  
...同时避免自身陷入。  
...without getting stuck themselves.  

343  
00:45:14,766 --> 00:45:16,800  
一次失足便定胜负。  
One trip is all it takes.  

344  
00:45:26,166 --> 00:45:27,966  
通过控制种群数量，  
By keeping numbers in check  

345  
00:45:27,966 --> 00:45:31,066  
剔除病弱个体，  
and removing the sick and the weak,  

346  
00:45:31,066 --> 00:45:34,200  
狼群实则帮助驯鹿族群保持健康。  
the wolves actually help the caribou herds stay healthy.  

347  
00:45:42,400 --> 00:45:44,766  
这对狼群至关重要，  
This is a vital meal for them,  

348  
00:45:44,766 --> 00:45:47,333  
对驯鹿种群影响却微乎其微。  
and a relatively small loss for the caribou.  

349  
00:45:57,000 --> 00:46:00,866  
二月时分，白昼渐长，  
By February, the days are getting longer  

350  
00:46:00,866 --> 00:46:02,400  
寒冬渐退。  
and winter is easing back.  

351  
00:46:06,766 --> 00:46:10,666  
近年冬季已不似往昔漫长。  
These days, it rarely lasts as long as it used to.  

352  
00:46:15,100 --> 00:46:17,333  
在圣劳伦斯湾，  
Here in the Gulf of St. Lawrence,  

353  
00:46:17,333 --> 00:46:20,100  
海冰已开始消融。  
the sea ice is already beginning to break.  

354  
00:46:31,133 --> 00:46:33,566  
但预计还能维持六周。  
But it should remain for another six weeks.  

355  
00:46:36,866 --> 00:46:40,000  
这片冰原对加拿大最多产的  
This is a vitally important breeding platform  

356  
00:46:40,000 --> 00:46:43,100  
海洋哺乳动物至关重要。  
for one of Canada's most prolific marine mammals.  

357  
00:46:47,533 --> 00:46:48,500  
格陵兰海豹。  
The harp seal.  

358  
00:47:01,666 --> 00:47:04,100  
成年海豹多数时间栖息海洋...  
Adults spend most of their lives out at sea...  

359  
00:47:08,700 --> 00:47:11,766  
...但每年返回冰原生育。  
...but return to the ice sheets each year to give birth.  

360  
00:47:14,866 --> 00:47:19,000  
这里每年诞生近20万只幼崽。  
Almost 200,000 pups are born here every year.  

361  
00:47:28,133 --> 00:47:30,366  
它们必须在冰原消融前  
And they need to become independent  

362  
00:47:30,366 --> 00:47:32,066  
学会独立生存。  
before the sea ice disappears.  

363  
00:47:54,066 --> 00:47:57,066  
所幸格陵兰海豹幼崽成长迅速。  
Luckily, baby harp seals are fast growers.  

364  
00:48:00,000 --> 00:48:03,800  
通过持续吮吸高脂母乳，  
By constantly suckling his mother's fat-rich milk,  

365  
00:48:03,800 --> 00:48:06,766  
幼崽每天能增重五磅。  
this pup can put on five pounds a day.  

366  
00:48:09,800 --> 00:48:12,066  
母海豹倾尽所有。  
His mother is dedicated.  

367  
00:48:12,066 --> 00:48:15,766  
断奶前绝不离开幼崽去觅食。  
She won't leave him to feed herself until he's fully weaned.  

368  
00:48:17,433 --> 00:48:19,900  
但这样的哺育仅能维持两周。  
But she can only keep this up for two weeks.  

369  
00:48:26,666 --> 00:48:28,366  
所幸进展顺利。  
Fortunately, she's on track.  

370  
00:48:29,566 --> 00:48:32,833  
第十天时幼崽已长大三倍。  
It's day 10 and he's already tripled in size.  

371  
00:48:49,833 --> 00:48:52,433  
它新生的厚实脂肪层  
His impressive new layer of blubber  

372  
00:48:52,433 --> 00:48:54,966  
即将面临终极考验...  
is about to be put to the ultimate test...  

373  
00:48:58,633 --> 00:49:00,333  
...首次游泳课。  
...his first swimming lesson.  

374  
00:49:10,733 --> 00:49:14,266  
必须在冰原融化前掌握这项技能。  
It's vital he learns these skills before the sea ice melts.  

375  
00:49:25,966 --> 00:49:27,600  
它显得十分抗拒。  
He seems very reluctant.  

376  
00:49:29,466 --> 00:49:31,200  
但母亲鼓励它下水。  
But Mom encourages him in.  

377  
00:49:41,600 --> 00:49:43,400  
终于成功入水。  
Finally, he's made it.  

378  
00:49:59,333 --> 00:50:02,900  
它似乎已适应这个广阔新世界。  
He seems very much at home in this big, new world.  

379  
00:50:07,866 --> 00:50:09,366  
母亲的使命已完成。  
His mother's work is done.  

380  
00:50:12,633 --> 00:50:14,633  
它将依托冰原庇护  
He'll stay close to the safety of the ice  

381  
00:50:14,633 --> 00:50:17,166  
直至最后一块浮冰消融，  
for as long as it stays frozen,  

382  
00:50:17,166 --> 00:50:19,200  
而后永久栖身海洋。  
before he takes to the water for good.  

383  
00:50:25,100 --> 00:50:29,166  
加拿大海岸线将是它的探索乐园。  
Canada's coastline will be his to explore.  

384  
00:50:34,733 --> 00:50:40,233  
春潮正席卷这片广袤国土。  
Right across this vast country, spring is gathering momentum.  

385  
00:50:45,066 --> 00:50:47,133  
冰雪加速消融...  
The snow and ice are melting fast...  

386  
00:50:51,366 --> 00:50:53,400  
...崭新世界徐徐展开。  
...giving way to a whole new world.  

387  
00:51:02,366 --> 00:51:05,066  
蓝绿交织的国度。  
A land of green and blue.  

388  
00:51:09,066 --> 00:51:11,200  
成千上万  
Thousands  

389  
00:51:09,066 --> 00:51:11,200  
湖泊重现人间。  
of lakes are revealed.  

390  
00:51:17,033 --> 00:51:19,800  
各类生灵的机遇之窗  
And windows of opportunity are opening up  

391  
00:51:19,800 --> 00:51:21,666  
正陆续开启。  
for all kinds of creatures.  

392  
00:51:42,466 --> 00:51:45,066  
加拿大是片极境之地。  
Canada is a land of extremes.  

393  
00:51:52,866 --> 00:51:56,400  
对栖居于此的野生动物而言，  
For the wild residents who call this home,  

394  
00:51:56,400 --> 00:51:59,266  
生死总是相伴相生。  
life and death go hand-in-hand.  

395  
00:52:03,766 --> 00:52:05,800  
但它们都学会适应...  
But they all learn to adapt...  

396  
00:52:07,366 --> 00:52:09,300  
...生存，  
...survive,  

397  
00:52:09,300 --> 00:52:10,566  
乃至繁荣...  
and even prosper...  

398  
00:52:12,300 --> 00:52:15,433  
...凭借抓住大自然在加拿大北部荒野...  
...by seizing the opportunities that nature provides...  

399  
00:52:18,200 --> 00:52:20,966  
...赐予的每个机遇。  
...in Canada's wild north.  

400  
00:52:57,833 --> 00:53:01,300  
欲了解本期《自然》节目更多内容，  
To learn more about what you've seen on this "Nature" program,  

401  
00:53:01,300 --> 00:53:03,233  
请访问pbs.org。  
visit pbs.org.