WEBVTT - How Do Kodiak Bears Work? 0:00:01.920 --> 0:00:07.240 Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff, 0:00:07.280 --> 0:00:11.720 Lauren Vogelbaum Here, there are currently eight different species of 0:00:11.720 --> 0:00:15.600 bears living here with us on planet Earth, but it's 0:00:15.640 --> 0:00:18.640 a bit more complicated than that. We'll take, for instance, 0:00:18.720 --> 0:00:22.000 the brown bear, whose range extends from the United States 0:00:22.000 --> 0:00:26.640 through Canada and far into China, Russia, and Scandinavia. There 0:00:26.680 --> 0:00:29.479 are many subspecies of brown bear that hang out in 0:00:29.720 --> 0:00:33.159 very specific nooks and crannies the Gobi Desert, for instance, 0:00:33.320 --> 0:00:37.360 or the Russian peninsula of Camchaca. But the largest of 0:00:37.360 --> 0:00:40.920 the brown bear subspecies is the Kodiak bear, which lives 0:00:41.000 --> 0:00:45.239 only on the Kodiak Archipelago off the southern coast of Alaska. 0:00:45.560 --> 0:00:48.120 The brown bear species is believed to have first evolved 0:00:48.159 --> 0:00:50.839 in Asia and spread into Europe around two hundred and 0:00:50.880 --> 0:00:54.120 fifty thousand years ago. Around a hundred thousand years ago, 0:00:54.280 --> 0:00:57.920 they likely moved into North America through Alaska, but didn't 0:00:57.920 --> 0:01:00.920 go farther south into the Lower forty eight until closer 0:01:00.960 --> 0:01:05.560 to between thirteen thousand and fifteen thousand years ago. For 0:01:05.720 --> 0:01:08.080 the article, this episode is based on How Stuff Work. 0:01:08.120 --> 0:01:11.640 Spoke by email with Shannon Finnegan, a PhD. Candidate at 0:01:11.680 --> 0:01:14.520 the State University of New York and a Kodiak bear 0:01:14.560 --> 0:01:18.280 researcher at the Alaska Department of Fishing Game Kodiak And. 0:01:18.319 --> 0:01:22.160 She said it's hard to say exactly how brown bears 0:01:22.319 --> 0:01:25.680 ended up in Kodiak, but the most agreed upon theory 0:01:25.920 --> 0:01:28.840 is that they likely crossed over from mainland Alaska via 0:01:28.920 --> 0:01:32.320 an ice bridge during the last ice age. It's believed 0:01:32.400 --> 0:01:35.480 that some of southern Kodiak may have been unglaciated at 0:01:35.480 --> 0:01:38.920 this point, and the first Kodiak brown bear population may 0:01:38.920 --> 0:01:42.600 have taken hold here. As the glacier retreated, the bear 0:01:42.600 --> 0:01:47.120 population likely expanded to occur all across the archipelago, taking 0:01:47.160 --> 0:01:51.600 advantage of the rich food supplies. The Kodiak Archipelago is 0:01:51.640 --> 0:01:54.960 a string of islands cut off from mainland Alaska, which 0:01:55.160 --> 0:01:59.920 is the perfect condition for a subspecies of anything to evolve. However, 0:02:00.360 --> 0:02:04.800 while distinguishing between similar animal species can be difficult, defining 0:02:04.840 --> 0:02:09.760 subspecies is even trickier. Biologists don't even completely agree about 0:02:09.800 --> 0:02:12.800 whether different groups of brown bears should be classified as 0:02:12.800 --> 0:02:18.800 subspecies or not. Finnigand said, generally speaking, all brown bears 0:02:18.840 --> 0:02:22.240 found across the world belonged to the same species. However, 0:02:22.520 --> 0:02:24.920 it is said that brown bears could be split into 0:02:24.960 --> 0:02:29.880 five clades based on some genetic and geographical differences. Within 0:02:30.000 --> 0:02:33.240 this clade system, Kodiak bears fit into a clade with 0:02:33.320 --> 0:02:39.360 bears from mainland Alaska. Clades are branches of evolution that 0:02:39.440 --> 0:02:44.480 include a single common ancestor and all of its descendants. 0:02:44.520 --> 0:02:47.480 Since the Kodiak bear has been living the island life 0:02:47.560 --> 0:02:50.119 for at least twelve thousand years, it's been cut off 0:02:50.200 --> 0:02:52.760 from others of its species for long enough to display 0:02:52.840 --> 0:02:57.119 some genetic differences. For instance, the Kodiak bear can grow 0:02:57.200 --> 0:02:59.920 to larger sizes than any other type of brown bear, 0:03:00.440 --> 0:03:03.360 weighing in it up to one thousand, five hundred pounds 0:03:03.520 --> 0:03:06.840 that's six d and eighty kilos. They rival the polar 0:03:06.840 --> 0:03:09.120 bear for the title of biggest bear in the world. 0:03:11.480 --> 0:03:14.760 And there's another reason Kodiak bears grow so large compared 0:03:14.800 --> 0:03:18.840 with their mainland counterparts. Their archipelago is rich in food 0:03:18.960 --> 0:03:23.519 like Pacific salmon, and there's relatively little competition from other predators. 0:03:25.120 --> 0:03:28.360 Bears may have a reputation for being aggressive, but according 0:03:28.400 --> 0:03:32.320 to Finnegan, Kodiak bears have harmoniously cohabitated with humans on 0:03:32.360 --> 0:03:35.480 their islands for a long time. There hasn't been a 0:03:35.560 --> 0:03:38.480 human fatality from a bear attack on Kodiak in over 0:03:38.560 --> 0:03:43.880 ninety years. Finnegan said they are extremely adaptable and curious 0:03:43.960 --> 0:03:48.280 animals with very distinctive personalities. Some bears around the city 0:03:48.320 --> 0:03:51.040 of Kodiak have even learned how to open car doors 0:03:51.120 --> 0:03:54.000 and bear proof dumpsters, which are very tricky to try 0:03:54.000 --> 0:03:58.960 and access human foods. Kodiak bears, like all brown bears, 0:03:59.200 --> 0:04:02.560 have the ability to delay implantation of a fertilized egg 0:04:02.640 --> 0:04:05.760 in the womb. That's how a female brown bear can 0:04:05.840 --> 0:04:08.160 give birth to a litter of cubs, all sired by 0:04:08.160 --> 0:04:12.720 different fathers. They usually breed in June, but won't become 0:04:12.760 --> 0:04:16.080 pregnant until later in the fall. Their bodies have to 0:04:16.120 --> 0:04:18.360 wait to see whether they can build up enough fat 0:04:18.360 --> 0:04:21.680 reserves to sustain a pregnancy and provide milk for offspring 0:04:21.760 --> 0:04:26.240 in the den. Kodiak bear populations seemed to be relatively 0:04:26.279 --> 0:04:31.159 stable at around three thousand, five hundred individuals on the archipelago. However, 0:04:31.480 --> 0:04:36.320 this wasn't always the case, Finnigan said. Historically, Kodiak bears 0:04:36.360 --> 0:04:39.839 were heavily persecuted on parts of the archipelago when cattle 0:04:39.920 --> 0:04:43.560 ranching was a prominent industry, they were viewed as vermin 0:04:43.680 --> 0:04:47.760 and exterminated whenever possible. Hunting groups on Kodiak took issue 0:04:47.800 --> 0:04:50.599 against this and fought to have protections put in place 0:04:50.640 --> 0:04:53.840 for the Kodiak bear. Thanks to the efforts of these 0:04:53.839 --> 0:04:57.000 sport hunters, huge swaths of land were set aside as 0:04:57.080 --> 0:05:00.719 protected refuge for this bear and their popular and increased 0:05:01.480 --> 0:05:05.080 illegal hunting of Kodiak bears does exist today, however, the 0:05:05.120 --> 0:05:10.320 population is closely managed, but as with many animal populations, 0:05:10.560 --> 0:05:14.520 climate change may impact Kodiak bears in the future, particularly 0:05:14.560 --> 0:05:18.560 if warming waters alter or negatively impact the Pacific salmon 0:05:18.640 --> 0:05:29.480 that they rely on for food. Today's episode is based 0:05:29.480 --> 0:05:31.840 on the article Alaska's Kodiak Bear is one of the 0:05:31.880 --> 0:05:34.320 Planet's biggest on how stuff works dot Com, written by 0:05:34.360 --> 0:05:37.320 Jescelin Shields. Brain Stuff is production of I Heart Radio 0:05:37.400 --> 0:05:39.320 in partnership with how stuff Works dot Com, and it's 0:05:39.360 --> 0:05:42.160 produced by Tyler Plain. Of four more podcasts from my 0:05:42.200 --> 0:05:45.080 heart Radio, visit the I heart Radio app, Apple Podcasts, 0:05:45.160 --> 0:05:47.039 or wherever you listen to your favorite shows.