1 00:00:01,840 --> 00:00:08,800 Speaker 1: Welcome to Brainstuff, a production of iHeartRadio, Hey Brainstuff. Lauren Vogelbaum. Here. 2 00:00:10,600 --> 00:00:15,440 Speaker 1: Each summer, for reasons we humans don't particularly understand, about 3 00:00:15,480 --> 00:00:19,880 Speaker 1: twelve thousand male Pacific walruses pack themselves onto the beaches 4 00:00:19,920 --> 00:00:22,759 Speaker 1: of Round Island, off the southwest coast of Alaska in 5 00:00:22,840 --> 00:00:26,960 Speaker 1: the Bering Sea. That's some nine million pounds worth of 6 00:00:27,040 --> 00:00:30,600 Speaker 1: walrus on a two mile long island. For a metric friends, 7 00:00:30,600 --> 00:00:33,960 Speaker 1: that's around four million kilos on a three kilometer stretch. 8 00:00:35,200 --> 00:00:39,160 Speaker 1: Known as rather gregarious creatures, the walruses may simply enjoy 9 00:00:39,159 --> 00:00:42,680 Speaker 1: one another's company, although they do occasionally jab a neighbor 10 00:00:42,760 --> 00:00:46,440 Speaker 1: with their long tusks to assert dominance. Or perhaps they're 11 00:00:46,479 --> 00:00:49,440 Speaker 1: trying to stay warm in the far below freezing temperatures. 12 00:00:50,479 --> 00:00:53,640 Speaker 1: Whatever they're up to, the female walruses are far away 13 00:00:54,200 --> 00:00:57,560 Speaker 1: in root, back from their yearly migration north, with calves 14 00:00:57,600 --> 00:01:02,280 Speaker 1: in tow. Whatever the reason for this month's long mail bonding, 15 00:01:02,680 --> 00:01:06,040 Speaker 1: it presents an ideal setting for scientists to study the mammal. 16 00:01:07,200 --> 00:01:10,120 Speaker 1: In the years since research began, biologists have learned a 17 00:01:10,160 --> 00:01:13,440 Speaker 1: lot about this hearty creature of the Arctic, whose name 18 00:01:13,560 --> 00:01:16,360 Speaker 1: possibly roots from a sort of funny combination of the 19 00:01:16,440 --> 00:01:21,520 Speaker 1: Dutch words for horse and whale. Walruses are the second 20 00:01:21,640 --> 00:01:24,680 Speaker 1: largest pinniped, which is an order of animals that also 21 00:01:24,680 --> 00:01:28,440 Speaker 1: include seals and sea lions. Only the elephant's seal can 22 00:01:28,480 --> 00:01:32,440 Speaker 1: grow larger. Walruses are also the only member of the 23 00:01:32,560 --> 00:01:36,959 Speaker 1: order to possess tusks, two especially long upper canines that 24 00:01:37,000 --> 00:01:39,920 Speaker 1: can reach lengths of three feet nearly a meter and 25 00:01:40,000 --> 00:01:44,759 Speaker 1: weigh twelve pounds each that's over five kilos. They primarily 26 00:01:44,880 --> 00:01:48,080 Speaker 1: use their tusks as built in tools for managing their 27 00:01:48,320 --> 00:01:52,040 Speaker 1: icy environments. They can hook their tusks into the ice 28 00:01:52,160 --> 00:01:54,480 Speaker 1: to pull themselves out of the water or just take 29 00:01:54,520 --> 00:01:58,440 Speaker 1: a break from swimming, or when underwater, break breathing holes 30 00:01:58,480 --> 00:02:02,320 Speaker 1: in the ice. Both the males and females have tusks, 31 00:02:02,440 --> 00:02:05,960 Speaker 1: but the males are longer, straighter, and stronger, and can 32 00:02:06,000 --> 00:02:10,040 Speaker 1: continue to grow for fifteen years. They do also use 33 00:02:10,080 --> 00:02:13,800 Speaker 1: them for establishing dominance when males get feisty. The especially 34 00:02:13,840 --> 00:02:16,560 Speaker 1: thick skin around their neck and shoulders protects them from 35 00:02:16,639 --> 00:02:21,120 Speaker 1: sharp jabs. Walruses are darkish brown in color and have 36 00:02:21,360 --> 00:02:26,000 Speaker 1: large round bodies. They seem clumsy on land, but after 37 00:02:26,040 --> 00:02:28,560 Speaker 1: all they spend About two thirds of their lives in water, 38 00:02:28,680 --> 00:02:31,120 Speaker 1: where they move easily and can dive down about the 39 00:02:31,240 --> 00:02:35,480 Speaker 1: length of an American football field. Walruses have four flippers 40 00:02:35,520 --> 00:02:38,640 Speaker 1: with rough bottoms to help provide traction on slippery snow 41 00:02:38,639 --> 00:02:41,560 Speaker 1: and ice. In the water, they can reach speeds of 42 00:02:41,560 --> 00:02:44,920 Speaker 1: about twenty miles an hour that's thirty five kilometers an hour. 43 00:02:46,080 --> 00:02:50,399 Speaker 1: There are two subspecies, the Atlantic walrus and the Pacific walrus, 44 00:02:50,600 --> 00:02:54,600 Speaker 1: which are totally isolated from each other. Pacific walruses are 45 00:02:54,639 --> 00:02:57,079 Speaker 1: a little bit bigger. They can top out at twelve 46 00:02:57,080 --> 00:02:59,520 Speaker 1: feet long that's three and a half meters and can 47 00:02:59,520 --> 00:03:02,360 Speaker 1: weigh up to thirty seven hundred pounds that's about seventeen 48 00:03:02,400 --> 00:03:06,080 Speaker 1: hundred kilos. In both subspecies, the males are a bit 49 00:03:06,120 --> 00:03:10,560 Speaker 1: bigger than the females. Walruses are located throughout the Arctic. 50 00:03:11,200 --> 00:03:14,240 Speaker 1: There are a lot more Pacific walruses and estimated two 51 00:03:14,320 --> 00:03:18,240 Speaker 1: hundred and fifty thousand versus only around fifty thousand Atlantic walruses. 52 00:03:18,919 --> 00:03:22,880 Speaker 1: Their populations are considered vulnerable due to previous overhunting and 53 00:03:23,200 --> 00:03:28,440 Speaker 1: now climate change. They are fabulously adapted for their environments. 54 00:03:29,120 --> 00:03:32,120 Speaker 1: Walruses live in one of the harshest environments on Earth, 55 00:03:33,080 --> 00:03:36,080 Speaker 1: temperatures are frigid, and again they spend most of their 56 00:03:36,160 --> 00:03:38,360 Speaker 1: time in the water, where you lose body heat a 57 00:03:38,400 --> 00:03:42,000 Speaker 1: lot faster. They have a thick layer of body fat 58 00:03:42,120 --> 00:03:45,080 Speaker 1: just under their skin that keeps them warm. It streamlines 59 00:03:45,120 --> 00:03:47,800 Speaker 1: their form and provides them with energy when the food 60 00:03:47,800 --> 00:03:51,840 Speaker 1: supply dips low. This blubbery layer can be up to 61 00:03:51,920 --> 00:03:55,480 Speaker 1: four inches thick some ten centimeters and may comprise a 62 00:03:55,520 --> 00:03:57,880 Speaker 1: whole third of the animal's body mass. In the winter, 63 00:03:59,200 --> 00:04:02,360 Speaker 1: the walrus blod vessels also con strict and move blood 64 00:04:02,360 --> 00:04:06,360 Speaker 1: away from skin and towards chief organs, where heat won't escape. 65 00:04:06,960 --> 00:04:10,000 Speaker 1: This is so effective that you can see it. When 66 00:04:10,000 --> 00:04:12,200 Speaker 1: a walrus has been under water for a long time, 67 00:04:12,480 --> 00:04:16,680 Speaker 1: its skin will go from pinkish to white. Their brown 68 00:04:16,720 --> 00:04:20,080 Speaker 1: hair is short and probably doesn't help in the warmth department. 69 00:04:21,160 --> 00:04:24,039 Speaker 1: Their circulation is also what helps them dive for long 70 00:04:24,120 --> 00:04:27,680 Speaker 1: periods without coming up for air. When they dive, their 71 00:04:27,680 --> 00:04:30,600 Speaker 1: heart rate slows and blood travels to the organs that 72 00:04:30,680 --> 00:04:34,080 Speaker 1: need the most oxygen. They also have a high level 73 00:04:34,080 --> 00:04:38,080 Speaker 1: of a protein called myoglobin in their blood. Myoglobin binds 74 00:04:38,080 --> 00:04:41,159 Speaker 1: to oxygen, carries it through the walrus's body and stores 75 00:04:41,200 --> 00:04:45,880 Speaker 1: it in the muscles. Because water doesn't allow for great visibility, 76 00:04:46,320 --> 00:04:51,159 Speaker 1: walruses have adapted other senses. The animal's ears too small 77 00:04:51,200 --> 00:04:54,240 Speaker 1: openings with protective flaps can detect noises up to a 78 00:04:54,320 --> 00:04:57,760 Speaker 1: mile away. That's over a kilometer and a half. Its 79 00:04:57,760 --> 00:05:00,440 Speaker 1: sense of smell can help it detect approaching predator and 80 00:05:00,520 --> 00:05:05,040 Speaker 1: identify its own young. In addition, a walrus has frankly 81 00:05:05,080 --> 00:05:08,279 Speaker 1: adorable whiskers, some four hundred to seven hundred of them 82 00:05:08,400 --> 00:05:12,479 Speaker 1: in thirteen to fifteen rows around the nose. They're attached 83 00:05:12,480 --> 00:05:15,400 Speaker 1: to muscles and supplied with blood and nerves, which makes 84 00:05:15,440 --> 00:05:19,599 Speaker 1: them highly sensitive. They use these whiskers to locate prey. 85 00:05:20,480 --> 00:05:24,360 Speaker 1: They hunt with their noses to the seafloor. They don't 86 00:05:24,400 --> 00:05:27,839 Speaker 1: actually use their tusks to dig for food, as previously thought, 87 00:05:28,200 --> 00:05:31,200 Speaker 1: but rather blow streams of water out of their nostrils 88 00:05:31,240 --> 00:05:35,360 Speaker 1: to stir up burrowing animals. They prefer clams, but will 89 00:05:35,480 --> 00:05:41,360 Speaker 1: eat anything they find, including worms, snails, crabs, and sea cucumbers. 90 00:05:41,360 --> 00:05:44,599 Speaker 1: Some of those animals have shells, and walruses don't chew 91 00:05:44,640 --> 00:05:47,360 Speaker 1: their food, so they can't crack the shells, but they 92 00:05:47,400 --> 00:05:50,960 Speaker 1: have an equally effective method. A walrus can use its 93 00:05:51,040 --> 00:05:53,880 Speaker 1: mouth as a vacuum to suck the animal right out 94 00:05:53,880 --> 00:05:58,320 Speaker 1: of its shell. This section is so powerful that in captivity, 95 00:05:58,600 --> 00:06:02,960 Speaker 1: walruses have sucked wholes and plywood and strict paint from walls. 96 00:06:04,000 --> 00:06:06,960 Speaker 1: Walruses consume some four to six percent of their body 97 00:06:07,000 --> 00:06:10,760 Speaker 1: weight every day, meaning an adult animal might consume six 98 00:06:10,839 --> 00:06:15,480 Speaker 1: thousand clans in one sitting. These animals have few predators 99 00:06:15,560 --> 00:06:18,680 Speaker 1: other than the occasional killer whale or brave polar bear. 100 00:06:19,680 --> 00:06:22,240 Speaker 1: Thus they tend to live relatively long life spans of 101 00:06:22,279 --> 00:06:27,240 Speaker 1: around thirty years. During their lifetimes, male and female walruses 102 00:06:27,360 --> 00:06:30,960 Speaker 1: live apart in separate herds. Females stay with the same 103 00:06:31,000 --> 00:06:33,800 Speaker 1: herd throughout their lives, and males leave their birth herd 104 00:06:33,839 --> 00:06:36,400 Speaker 1: after two or three years to join the male herd. 105 00:06:37,560 --> 00:06:40,479 Speaker 1: As we said at the top, Pacific female herds migrate 106 00:06:40,560 --> 00:06:44,599 Speaker 1: every year. We know less about the Atlantic walrus, but 107 00:06:44,640 --> 00:06:47,920 Speaker 1: they don't seem to migrate in the summer. When the 108 00:06:47,960 --> 00:06:51,800 Speaker 1: ice melts and recedes, the Pacific females head north then 109 00:06:51,920 --> 00:06:56,040 Speaker 1: return south before the ice freezes in the winter. Researchers 110 00:06:56,120 --> 00:06:58,279 Speaker 1: aren't sure why the males don't migrate to the same 111 00:06:58,279 --> 00:07:01,679 Speaker 1: extent that females do might have to do with sperm production. 112 00:07:03,000 --> 00:07:05,640 Speaker 1: The herds meet in the winter. When the females head south, 113 00:07:06,360 --> 00:07:10,240 Speaker 1: they'll congregate on an ice pack and basically be serenaded 114 00:07:10,280 --> 00:07:13,640 Speaker 1: by the males, which inflate pouches near their throat to 115 00:07:13,720 --> 00:07:17,520 Speaker 1: remain upright in the water and vocalize, clacking their teeth, 116 00:07:17,680 --> 00:07:20,840 Speaker 1: whistling and making bell sounds until one of the females 117 00:07:20,880 --> 00:07:25,840 Speaker 1: is impressed enough to come mate. Pregnancy lasts about fifteen months, 118 00:07:26,000 --> 00:07:28,800 Speaker 1: so calves are born in the spring during migration north. 119 00:07:29,640 --> 00:07:32,520 Speaker 1: Mothers are very protective of their young and may form 120 00:07:32,560 --> 00:07:36,880 Speaker 1: a separate nursery herd with other cows. Females stay close 121 00:07:36,920 --> 00:07:39,640 Speaker 1: to their newborns for at least a year and sometimes 122 00:07:39,680 --> 00:07:44,000 Speaker 1: over two years, and may nurse that entire time. Cows 123 00:07:44,040 --> 00:07:46,440 Speaker 1: often give their young rides on their backs, even though 124 00:07:46,480 --> 00:07:50,080 Speaker 1: calves can usually swim after just a month or so. 125 00:07:50,120 --> 00:07:53,520 Speaker 1: Those calves are big bundles of joy. They can weigh 126 00:07:53,520 --> 00:07:55,680 Speaker 1: from one hundred to one hundred and sixty pounds of 127 00:07:55,720 --> 00:07:59,480 Speaker 1: birth that's forty five to seventy five kilos. They tend 128 00:07:59,480 --> 00:08:01,600 Speaker 1: to be darker than the adults in color and get 129 00:08:01,640 --> 00:08:07,040 Speaker 1: lighter as they age. They're very social and seemingly smart creatures. 130 00:08:07,840 --> 00:08:11,160 Speaker 1: Young males have been observed keeping watch over injured walruses 131 00:08:11,400 --> 00:08:14,320 Speaker 1: and pushing dead or dying walruses off of ice floes 132 00:08:14,360 --> 00:08:18,560 Speaker 1: so that nearby hunters can't get to them. Female walruses 133 00:08:18,600 --> 00:08:22,720 Speaker 1: may also carry their dead young away from hunters. Though 134 00:08:22,760 --> 00:08:26,120 Speaker 1: walruses have few natural predators, humans have hunted them for 135 00:08:26,320 --> 00:08:31,080 Speaker 1: thousands of years for their meat, tusks, bones, skin, and oil. 136 00:08:32,320 --> 00:08:35,520 Speaker 1: In the mid to late eighteen hundreds, in particular, walrus oil, 137 00:08:35,800 --> 00:08:39,400 Speaker 1: created by boiling walrus blubber at high temperatures, was sought 138 00:08:39,440 --> 00:08:44,000 Speaker 1: for lamps, soap, and as a machine lubricant. From eighteen 139 00:08:44,040 --> 00:08:47,319 Speaker 1: sixty to eighteen eighty, some ten thousand walruses were killed 140 00:08:47,360 --> 00:08:51,640 Speaker 1: every year in the Eastern Arctic alone. Walrus hunting has 141 00:08:51,679 --> 00:08:55,640 Speaker 1: since been restricted generally only two native populations who have 142 00:08:55,760 --> 00:08:58,319 Speaker 1: traditionally relied on the walrus as a source of food 143 00:08:58,480 --> 00:09:03,360 Speaker 1: and other supplies. In Alaska, for example, peoples like the 144 00:09:03,360 --> 00:09:07,080 Speaker 1: Inupia and the Upic have historically used every part of 145 00:09:07,080 --> 00:09:11,440 Speaker 1: the animal. Stomachs can be made into containers and drums, 146 00:09:11,760 --> 00:09:15,320 Speaker 1: a skins made into boat covers and rope, and ivory 147 00:09:15,520 --> 00:09:20,920 Speaker 1: is used in art. Local management keeps harvests within sustainable limits. 148 00:09:21,880 --> 00:09:24,400 Speaker 1: In the United States, the Marine Mammal Protection Act of 149 00:09:24,480 --> 00:09:27,920 Speaker 1: nineteen seventy two protects the walrus from hunters and prohibits 150 00:09:27,920 --> 00:09:32,200 Speaker 1: the trade of walrus ivory. Only ivory that predates the 151 00:09:32,280 --> 00:09:35,160 Speaker 1: law or has been carved by an Alaska native can 152 00:09:35,280 --> 00:09:39,760 Speaker 1: legally be sold. Other national and international laws protect the 153 00:09:39,800 --> 00:09:43,800 Speaker 1: animals from harvest and restrict global trade of walrus products. 154 00:09:44,800 --> 00:09:49,600 Speaker 1: These measures have stabilized walrus populations, but unfortunately they now 155 00:09:49,640 --> 00:09:56,040 Speaker 1: face another threat, global warming. As Earth's average temperature increases, 156 00:09:56,440 --> 00:10:00,439 Speaker 1: more and more ice in the polar region recedes. This 157 00:10:00,520 --> 00:10:03,880 Speaker 1: could be devastating to walruses because they depend on the 158 00:10:03,880 --> 00:10:08,120 Speaker 1: ice shelves as a resting ground between dives. The shallow 159 00:10:08,160 --> 00:10:11,480 Speaker 1: waters where walruses like to feed now have little or 160 00:10:11,520 --> 00:10:14,480 Speaker 1: no ice for mothers and babies to rest on when feeding. 161 00:10:15,640 --> 00:10:18,440 Speaker 1: As a result, mothers may have to travel farther to 162 00:10:18,480 --> 00:10:22,439 Speaker 1: reach feeding and resting grounds. This means they may become 163 00:10:22,480 --> 00:10:26,600 Speaker 1: separated from their young. Areas that do have ice shelves 164 00:10:26,640 --> 00:10:29,640 Speaker 1: are deeper, and the walruses aren't accustomed to diving that 165 00:10:29,760 --> 00:10:33,880 Speaker 1: deep for food. Only time will tell whether the walrus 166 00:10:33,880 --> 00:10:37,160 Speaker 1: can adapt to the longer commute and deeper dives required 167 00:10:37,440 --> 00:10:44,880 Speaker 1: because of the ICE's retreat. Today's episode is based on 168 00:10:44,880 --> 00:10:47,920 Speaker 1: the article how Walruses work on how stuffworks dot Com, 169 00:10:47,960 --> 00:10:51,079 Speaker 1: written by Jennifer Wharton. Brain Stuff is production by Heart 170 00:10:51,160 --> 00:10:53,520 Speaker 1: Radio in partnership with how Stuffwork dot Com and is 171 00:10:53,559 --> 00:10:56,920 Speaker 1: produced by Tyler Klang. For more podcasts from My heart Radio, 172 00:10:57,240 --> 00:11:00,360 Speaker 1: visit the heart Radio app, Apple Podcasts, or wherevery listen 173 00:11:00,400 --> 00:11:01,439 Speaker 1: to your favorite shows.