1 00:00:00,000 --> 00:00:04,040 Unit 11, page 178. Read. 2 00:00:05,600 --> 00:00:08,540 Going, going, gone? 3 00:00:09,060 --> 00:00:15,580 What do the auroch, the passenger pigeon, and the western black rhinoceros have in common? 4 00:00:16,240 --> 00:00:19,140 The answer, they've all gone extinct. 5 00:00:20,180 --> 00:00:24,920 These vanished animals typify the problem of the disappearance of species. 6 00:00:26,000 --> 00:00:29,880 Several grim statistics indicate the seriousness of the issue. 7 00:00:30,720 --> 00:00:36,060 Today, more than 18,000 species are thought to be in danger of extinction. 8 00:00:36,520 --> 00:00:42,220 This means that over 40% of the world's animals are considered at risk. 9 00:00:43,140 --> 00:00:50,180 It is also estimated that about one-half of the world's animal species have disappeared since 1970. 10 00:00:51,420 --> 00:00:55,740 Many feel that something must be done to stop this, and soon. 11 00:00:56,520 --> 00:00:57,200 But what? 12 00:00:58,000 --> 00:00:59,960 Some animals have been extinct. 13 00:01:00,000 --> 00:01:02,200 Some animals have been extinct for a considerable time. 14 00:01:02,960 --> 00:01:10,980 Aurochs, large wild oxen that lived in Europe and Asia, had died out by the early 1600s. 15 00:01:11,620 --> 00:01:16,300 The passenger pigeon was once the most common bird in North America. 16 00:01:17,300 --> 00:01:21,220 Historically, it populated the eastern U.S. and Canada. 17 00:01:21,220 --> 00:01:29,920 But by the end of the 19th century, it had almost disappeared because of habitat destruction and excessive hunting. 18 00:01:30,760 --> 00:01:40,680 The last known passenger pigeon, a female named Martha, died at the Cincinnati Zoo on September 1, 1914. 19 00:01:42,220 --> 00:01:50,140 More recently, we have lost the western black rhinoceros, which lived in the southeastern part of the African continent. 20 00:01:51,140 --> 00:01:57,320 It declined greatly over the 20th century and was last seen in 2008. 21 00:01:57,720 --> 00:01:59,820 It was officially declared extinct. 22 00:02:00,000 --> 00:02:03,120 It was officially declared extinct on November 6, 2013. 23 00:02:04,620 --> 00:02:08,180 Which animals are presently in danger of extinction? 24 00:02:08,180 --> 00:02:11,700 There are three significant categories. 25 00:02:12,600 --> 00:02:16,220 Critically endangered, endangered, and vulnerable. 26 00:02:17,520 --> 00:02:25,540 Those considered critically endangered include the mountain gorilla of Central Africa and the California condor. 27 00:02:26,640 --> 00:02:29,980 Those termed endangered include the Asian elephant, the African elephant, and the African elephant. 28 00:02:30,000 --> 00:02:39,860 Those considered vulnerable include the African lion and the polar bear of northern North America. 29 00:02:40,660 --> 00:02:43,360 The picture looks bleak overall. 30 00:02:44,220 --> 00:02:47,420 Nevertheless, the situation is not hopeless. 31 00:02:48,280 --> 00:02:52,940 There have been a few successes in bringing animals back from the edge of extinction. 32 00:02:53,820 --> 00:02:57,940 The whooping cranes of Canada and the United States are one example. 33 00:02:58,680 --> 00:02:59,880 In 1940, the African lion was the first to be extinct. 34 00:02:59,880 --> 00:02:59,980 The African lion was the first to be extinct. 35 00:02:59,980 --> 00:03:00,000 The African lion was the first to be extinct. 36 00:03:00,000 --> 00:03:05,300 In 1941, there were only 21 cranes in captivity and two in the wild. 37 00:03:06,360 --> 00:03:11,680 By 2015, there were estimated to be 603 birds in the wild. 38 00:03:12,700 --> 00:03:19,740 Their story can be considered a limited recovery, though there is still a potential problem of species diversity. 39 00:03:20,860 --> 00:03:25,420 The humpback whale is another species that has made something of a comeback, 40 00:03:25,720 --> 00:03:29,640 particularly since the ban on commercial whaling was instituted. 41 00:03:30,200 --> 00:03:35,320 Human activity is by far the most significant cause of animal extinction. 42 00:03:36,560 --> 00:03:43,960 The most crucial problem is loss of habitat caused by the increase of human population and its associated development. 43 00:03:45,160 --> 00:03:51,420 This includes expanded farming, excessive hunting, poaching, and man-made pollution. 44 00:03:52,360 --> 00:03:59,880 To that, we can add climate change and the effects of invasive species that overwhelm the native animals of an area. 45 00:04:00,000 --> 00:04:02,140 What can we do? 46 00:04:02,980 --> 00:04:05,260 Several strategies have been suggested. 47 00:04:06,420 --> 00:04:10,260 1. Reduce our use of meat and dairy products. 48 00:04:11,060 --> 00:04:13,960 2. Focus on renewable energy. 49 00:04:15,020 --> 00:04:17,580 3. Change our shopping habits. 50 00:04:18,700 --> 00:04:21,960 4. Support laws that restrict development. 51 00:04:22,960 --> 00:04:29,980 And 5. Support efforts to protect the rainforests, wetlands, coral reefs, and grasslands. 52 00:04:30,980 --> 00:04:33,640 There is need for alarm. 53 00:04:34,460 --> 00:04:39,680 If we're concerned about the loss of species, we need to make our voices heard. 54 00:04:40,400 --> 00:04:43,660 Once an animal is gone, it is gone forever. 55 00:04:46,970 --> 00:04:51,410 Visit Mikael Books on Facebook to see more content about books in English.