Speaker 1: Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff,
Speaker 1: Lauren Vogelbaum Here, there are currently eight different species of
Speaker 1: bears living here with us on planet Earth, but it's
Speaker 1: a bit more complicated than that. We'll take, for instance,
Speaker 1: the brown bear, whose range extends from the United States
Speaker 1: through Canada and far into China, Russia, and Scandinavia. There
Speaker 1: are many subspecies of brown bear that hang out in
Speaker 1: very specific nooks and crannies the Gobi Desert, for instance,
Speaker 1: or the Russian peninsula of Camchaca. But the largest of
Speaker 1: the brown bear subspecies is the Kodiak bear, which lives
Speaker 1: only on the Kodiak Archipelago off the southern coast of Alaska.
Speaker 1: The brown bear species is believed to have first evolved
Speaker 1: in Asia and spread into Europe around two hundred and
Speaker 1: fifty thousand years ago. Around a hundred thousand years ago,
Speaker 1: they likely moved into North America through Alaska, but didn't
Speaker 1: go farther south into the Lower forty eight until closer
Speaker 1: to between thirteen thousand and fifteen thousand years ago. For
Speaker 1: the article, this episode is based on How Stuff Work.
Speaker 1: Spoke by email with Shannon Finnegan, a PhD. Candidate at
Speaker 1: the State University of New York and a Kodiak bear
Speaker 1: researcher at the Alaska Department of Fishing Game Kodiak And.
Speaker 1: She said it's hard to say exactly how brown bears
Speaker 1: ended up in Kodiak, but the most agreed upon theory
Speaker 1: is that they likely crossed over from mainland Alaska via
Speaker 1: an ice bridge during the last ice age. It's believed
Speaker 1: that some of southern Kodiak may have been unglaciated at
Speaker 1: this point, and the first Kodiak brown bear population may
Speaker 1: have taken hold here. As the glacier retreated, the bear
Speaker 1: population likely expanded to occur all across the archipelago, taking
Speaker 1: advantage of the rich food supplies. The Kodiak Archipelago is
Speaker 1: a string of islands cut off from mainland Alaska, which
Speaker 1: is the perfect condition for a subspecies of anything to evolve. However,
Speaker 1: while distinguishing between similar animal species can be difficult, defining
Speaker 1: subspecies is even trickier. Biologists don't even completely agree about
Speaker 1: whether different groups of brown bears should be classified as
Speaker 1: subspecies or not. Finnigand said, generally speaking, all brown bears
Speaker 1: found across the world belonged to the same species. However,
Speaker 1: it is said that brown bears could be split into
Speaker 1: five clades based on some genetic and geographical differences. Within
Speaker 1: this clade system, Kodiak bears fit into a clade with
Speaker 1: bears from mainland Alaska. Clades are branches of evolution that
Speaker 1: include a single common ancestor and all of its descendants.
Speaker 1: Since the Kodiak bear has been living the island life
Speaker 1: for at least twelve thousand years, it's been cut off
Speaker 1: from others of its species for long enough to display
Speaker 1: some genetic differences. For instance, the Kodiak bear can grow
Speaker 1: to larger sizes than any other type of brown bear,
Speaker 1: weighing in it up to one thousand, five hundred pounds
Speaker 1: that's six d and eighty kilos. They rival the polar
Speaker 1: bear for the title of biggest bear in the world.
Speaker 1: And there's another reason Kodiak bears grow so large compared
Speaker 1: with their mainland counterparts. Their archipelago is rich in food
Speaker 1: like Pacific salmon, and there's relatively little competition from other predators.
Speaker 1: Bears may have a reputation for being aggressive, but according
Speaker 1: to Finnegan, Kodiak bears have harmoniously cohabitated with humans on
Speaker 1: their islands for a long time. There hasn't been a
Speaker 1: human fatality from a bear attack on Kodiak in over
Speaker 1: ninety years. Finnegan said they are extremely adaptable and curious
Speaker 1: animals with very distinctive personalities. Some bears around the city
Speaker 1: of Kodiak have even learned how to open car doors
Speaker 1: and bear proof dumpsters, which are very tricky to try
Speaker 1: and access human foods. Kodiak bears, like all brown bears,
Speaker 1: have the ability to delay implantation of a fertilized egg
Speaker 1: in the womb. That's how a female brown bear can
Speaker 1: give birth to a litter of cubs, all sired by
Speaker 1: different fathers. They usually breed in June, but won't become
Speaker 1: pregnant until later in the fall. Their bodies have to
Speaker 1: wait to see whether they can build up enough fat
Speaker 1: reserves to sustain a pregnancy and provide milk for offspring
Speaker 1: in the den. Kodiak bear populations seemed to be relatively
Speaker 1: stable at around three thousand, five hundred individuals on the archipelago. However,
Speaker 1: this wasn't always the case, Finnigan said. Historically, Kodiak bears
Speaker 1: were heavily persecuted on parts of the archipelago when cattle
Speaker 1: ranching was a prominent industry, they were viewed as vermin
Speaker 1: and exterminated whenever possible. Hunting groups on Kodiak took issue
Speaker 1: against this and fought to have protections put in place
Speaker 1: for the Kodiak bear. Thanks to the efforts of these
Speaker 1: sport hunters, huge swaths of land were set aside as
Speaker 1: protected refuge for this bear and their popular and increased
Speaker 1: illegal hunting of Kodiak bears does exist today, however, the
Speaker 1: population is closely managed, but as with many animal populations,
Speaker 1: climate change may impact Kodiak bears in the future, particularly
Speaker 1: if warming waters alter or negatively impact the Pacific salmon
Speaker 1: that they rely on for food. Today's episode is based
Speaker 1: on the article Alaska's Kodiak Bear is one of the
Speaker 1: Planet's biggest on how stuff works dot Com, written by
Speaker 1: Jescelin Shields. Brain Stuff is production of I Heart Radio
Speaker 1: in partnership with how stuff Works dot Com, and it's
Speaker 1: produced by Tyler Plain. Of four more podcasts from my
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