1
00:00:07,058 --> 00:00:08,700
Have you ever heard the sound of frogs

2
00:00:08,700 --> 00:00:10,120
calling at night?

3
00:00:10,120 --> 00:00:11,876
For hundreds of millions of years,

4
00:00:11,876 --> 00:00:15,058
this croaking lullaby has filled the nighttime air.

5
00:00:15,058 --> 00:00:16,645
But recent studies suggest

6
00:00:16,645 --> 00:00:18,229
that these frogs are in danger

7
00:00:18,229 --> 00:00:20,314
of playing their final note.

8
00:00:20,314 --> 00:00:21,900
Over the past few decades,

9
00:00:21,900 --> 00:00:25,779
amphibian populations have been rapidly disappearing worldwide.

10
00:00:25,779 --> 00:00:28,240
Nearly one-third of the world's amphibian species

11
00:00:28,240 --> 00:00:29,834
are endanger of extinction,

12
00:00:29,834 --> 00:00:32,874
and over 100 species have already disappeared.

13
00:00:32,874 --> 00:00:35,415
But don't worry, there's still hope.

14
00:00:35,415 --> 00:00:37,341
Before we get into how to save the frogs,

15
00:00:37,341 --> 00:00:38,804
let's start by taking a look

16
00:00:38,804 --> 00:00:40,168
at why they're disappearing

17
00:00:40,168 --> 00:00:42,680
and why it's important to keep them around.

18
00:00:42,680 --> 00:00:44,920
Habitat destruction is the number one problem

19
00:00:44,920 --> 00:00:47,352
for frog populations around the world.

20
00:00:47,352 --> 00:00:49,698
There are seven billion humans on the planet,

21
00:00:49,698 --> 00:00:52,029
and we compete with frogs for habitat.

22
00:00:52,029 --> 00:00:54,341
We build cities, suburbs, and farms

23
00:00:54,341 --> 00:00:55,758
on top of frog habitat

24
00:00:55,758 --> 00:00:57,116
and chop forests

25
00:00:57,116 --> 00:00:58,115
and drain the wetlands

26
00:00:58,115 --> 00:00:59,052
that serve as home

27
00:00:59,052 --> 00:01:01,542
for numerous amphibian populations.

28
00:01:01,542 --> 00:01:04,293
Climate change alters precipitation levels,

29
00:01:04,293 --> 00:01:07,658
drying up ponds, streams, and cloud forests.

30
00:01:07,658 --> 00:01:10,340
As the Earth's human population continues to grow,

31
00:01:10,340 --> 00:01:13,168
so will the threats amphibians face.

32
00:01:13,168 --> 00:01:14,797
There are a variety of other factors

33
00:01:14,797 --> 00:01:17,060
contributing to the frogs' decline.

34
00:01:17,060 --> 00:01:19,316
Over-harvesting for the pet and food trade

35
00:01:19,316 --> 00:01:20,756
results in millions of frogs

36
00:01:20,756 --> 00:01:23,310
being taken out of the wild each year.

37
00:01:23,310 --> 00:01:24,425
Invasive species,

38
00:01:24,425 --> 00:01:26,477
such as non-native trout and crawfish,

39
00:01:26,477 --> 00:01:28,009
eat native frogs.

40
00:01:28,009 --> 00:01:29,477
Humans are facilitating the spread

41
00:01:29,477 --> 00:01:30,851
of infectious diseases

42
00:01:30,851 --> 00:01:32,925
by shipping over 100 million amphibians

43
00:01:32,925 --> 00:01:34,701
around the world each year

44
00:01:34,701 --> 00:01:37,032
for use as food, pets, bait,

45
00:01:37,032 --> 00:01:38,487
and in laboratories and zoos,

46
00:01:38,487 --> 00:01:41,280
with few regulations or quarantines.

47
00:01:41,280 --> 00:01:42,839
One of these diseases,

48
00:01:42,839 --> 00:01:44,292
chytridiomycosis,

49
00:01:44,292 --> 00:01:46,565
has driven stream-dwelling amphibian populations

50
00:01:46,565 --> 00:01:47,874
to extinction

51
00:01:47,874 --> 00:01:48,651
in Africa,

52
00:01:48,651 --> 00:01:49,332
Australia,

53
00:01:49,332 --> 00:01:49,925
Europe,

54
00:01:49,925 --> 00:01:52,420
and North, Central, and South America.

55
00:01:52,420 --> 00:01:54,259
On top of all these problems,

56
00:01:54,259 --> 00:01:57,133
we add hundreds of millions of kilograms of pesticides

57
00:01:57,133 --> 00:01:59,143
to our ecosystems each year.

58
00:01:59,143 --> 00:02:00,898
And these chemicals are easily absorbed

59
00:02:00,898 --> 00:02:02,889
through amphibians' permeable skin,

60
00:02:02,889 --> 00:02:04,634
causing immunosuppression,

61
00:02:04,634 --> 00:02:05,838
or a weakened immune system,

62
00:02:05,838 --> 00:02:08,226
and developmental deformities.

63
00:02:08,902 --> 00:02:10,809
Okay, so why are these little green guys

64
00:02:10,809 --> 00:02:12,309
worth keeping around?

65
00:02:12,309 --> 00:02:14,836
Frogs are important for a multitude of reasons.

66
00:02:14,836 --> 00:02:16,652
They're an integral part of the food web,

67
00:02:16,652 --> 00:02:18,840
eating flies, ticks, mosquitoes,

68
00:02:18,840 --> 00:02:20,208
and other disease vectors,

69
00:02:20,208 --> 00:02:22,614
thus, protecting us against malaria,

70
00:02:22,614 --> 00:02:23,649
dengue fever,

71
00:02:23,649 --> 00:02:25,343
and other illnesses.

72
00:02:25,343 --> 00:02:27,049
Tadpoles keep waterways clean

73
00:02:27,049 --> 00:02:28,262
by feeding on algae,

74
00:02:28,262 --> 00:02:29,335
reducing the demand

75
00:02:29,335 --> 00:02:31,419
on our community's filtration systems

76
00:02:31,419 --> 00:02:33,839
and keeping our cost of water low.

77
00:02:33,839 --> 00:02:35,512
Frogs serve as a source of food

78
00:02:35,512 --> 00:02:39,468
for birds, fish, snakes, dragonflies, and even monkeys.

79
00:02:39,468 --> 00:02:40,843
When frogs disappear,

80
00:02:40,843 --> 00:02:42,425
the food web is disturbed,

81
00:02:42,425 --> 00:02:45,059
and other animals can disappear as well.

82
00:02:45,059 --> 00:02:47,228
Amphibians are also extremely important

83
00:02:47,228 --> 00:02:48,725
in human medicine.

84
00:02:48,725 --> 00:02:50,756
Over ten percent of the Nobel prizes

85
00:02:50,756 --> 00:02:52,354
in physiology and medicine

86
00:02:52,354 --> 00:02:53,362
have gone to researchers

87
00:02:53,362 --> 00:02:56,169
whose work depended on amphibians.

88
00:02:56,169 --> 00:02:58,074
Some of the antimicrobial peptides

89
00:02:58,074 --> 00:03:00,473
on frog skin can kill HIV,

90
00:03:00,473 --> 00:03:01,954
some act as pain killers,

91
00:03:01,954 --> 00:03:05,063
and others serve as natural mosquito repellents.

92
00:03:05,063 --> 00:03:06,710
Many discoveries await us

93
00:03:06,710 --> 00:03:08,160
if we can save the frogs,

94
00:03:08,160 --> 00:03:10,117
but when a frog species disappears,

95
00:03:10,117 --> 00:03:11,556
so does any promise it holds

96
00:03:11,556 --> 00:03:13,678
for improving human health.

97
00:03:13,678 --> 00:03:16,309
Fortunately, there are lots of ways you can help,

98
00:03:16,309 --> 00:03:17,641
and the best place to start

99
00:03:17,641 --> 00:03:19,925
is by improving your ecological footprint

100
00:03:19,925 --> 00:03:21,711
and day-to-day actions.

101
00:03:21,711 --> 00:03:24,228
The next time you listen to that nighttime lullaby,

102
00:03:24,228 --> 00:03:26,854
don't think of it as just another background noise,

103
00:03:26,854 --> 00:03:28,390
hear it as a call for help,

104
00:03:28,390 --> 00:03:30,517
sung in perfect croaking harmony.