Koalas: When Stupidity is a Survival Strategy

[Music] australia home to some of the world's most dangerous venomous species both on land and under water and high up in the trees lives an animal that consumes so many toxins that it has few natural predators the koala hi i'm danielle dufoe and you're watching animal logic today we're in great outway national park and we're on the lookout for koalas found along the eastern coast and parts of southern australia the koala is the species of marsupial best known for its chill attitude cuddly appearance and teeny tiny brain [Music] today we're going for a hike along kennett river and it's well known for its population of koalas just off the great ocean road the atway coast is prime koala territory [Music] only a few dozen meters in land from the stunning cliffs and beaches of the coast the giant eucalyptus trees tower over this mountainous terrain growing upwards of 130 meters tall these eucalyptus trees serve as the perfect home for australia's biggest chillers we're really hoping that we might catch a few today just not too sure yet about how high we have to look up some of these trees are enormous [Music] a sure sign that we're in the right place i just found a bunch of koala scat i mean i might be in the danger zone of uh having some fall down on me too [Music] guys this is insane we've been hiking for just a couple minutes and already oh i don't know if you can see it way up there in this tree right where i'm pointing there's a koala high up in the tree canopy we've caught a koala red-handed munching away on his favorite meal we having a snack up there koalas are not good fighters they're not good runners and they're not good showboaters if they had to compete with other animals they would lose in every category lucky for them they are unique in the animal world and face zero competition why well it's because their food is toxic they're one of the only species that can subsist on eucalypt leaves alone and eucalyptus leaves are super toxic consuming more than just 3.5 milliliters of eucalyptus oil can be fatal to humans koalas have guts of steel they're able to digest toxic eucalyptus thanks to a specialized gut bacteria that they get from their mothers when they're close to leaving the pouch the mothers will feed their joey's pep a specialized form of feces that contains the bacteria necessary to break down the toxins in eucalyptus not only is eucalyptus toxic but it's also not very nutritious and so koalas need to eat a lot of it they can eat up to 500 grams every single day but it doesn't give them much energy so they're not very excited creatures [Music] they actually sleep for up to 22 hours a day and a lot of that time is spent digesting all that food they have an elongated digestive tract in order to process such large amounts of low energy food the cecum where most of the necessary gut bacteria is located can be up to two meters long the largest relative to body size of any animal the eucalyptus can stain the cecum for over 100 hours fermenting and breaking down toxins with their specialized digestive enzymes koalas actually obtain most of the moisture they need from the eucalyptus leaves females who are a little bit smaller usually tend to depend entirely on their nutrition to obtain the water they need to survive males are a little bit larger and especially in breeding season they'll seek out other sources of water for the most part it's all all in the package of one leaf if almost exclusively eating a toxic leaf wasn't enough koalas are quite particular about which of those leaves they'll eat [Music] australia has hundreds of species of eucalyptus tree when it comes to choosing food and refuge koalas are actually very very picky about what trees and what species they're going to use a lot of that different flavor depends on what kind of soil it's growing on a richer soil will taste better to them they tend to dislike eucalyptus trees that are growing in poor soil koalas are so adapted to the specific strain of eucalyptus they like that often once they've eaten all the leaves that they like in their range they'll simply give up and starve to death unable to digest a new type of leaf the other consequence of their diet is their teeny tiny brains koalas have one of the smallest brain to body size ratios in the mammalian world but don't hold it against them this might be an adaptation for life with a very calorie deficient diet big brains are very energetically expensive and being a dumb dumb means you have to eat less but the biggest advantage they get from having a toxic diet is not only do they have zero cross-species competition for their food source but they have almost no natural predators they're pretty much the only animal that does feed on eucalyptus which is considered to be poisonous for just about every other animal except for these guys they end up taking a lot of those toxins into their own tissues and end up tasting pretty terrible but their gut and brain aren't their only evolutionary tools for a life in eucalyptus trees koalas like the one behind me have super well adapted dentition that's designed to help them clip and pinch off all those leaves and then grind them in their back molars koalas are perfectly adapted for life in the trees and they have one specialized adaptation that not only helps them sleep without falling but makes them amazing climbers as well their hands he's got some very impressive claws there which help him hang on to branches and climb trees look at that he's got he's got quite a good grasp on there i'm impressed [Music] not only do they have really great claws for gripping onto branches but they have almost like two functional thumbs so they can grip around a branch and climb really really efficiently they're quite amazing spending their lives sitting in the trees they have one clever adaptation that makes their lives a little bit more comfortable along the base of their spine they have a cartilaginous pad that kind of creates a buffer and a little bit of protection for wedging itself between between tree branches and being able to sit like this comfortably all day long but all those adaptations are useless if they stand out okay there's a koala up here somewhere but i need to try and find it koalas are really hard to see because they blend in so well with these stripped bare trees they're about the same color as the bark oh there he is he's way at the top up there i see him he's scratching himself if you do happen to see a koala in the wild just don't get too close you might get wet oh and don't stand under the koala you might get an accidental shower koalas differ in size depending on location and sex in the south of australia they're almost twice as large as koalas from the north you can tell the males apart from the females mostly by size the males get quite a bit bigger and burlier the males are always larger than the females and have a broader face and a chest gland that they use to mark territory one thing that really sets apart male koalas from female koalas other than the obvious is that they have scent glands in their chest you might be able to see right between his pectoral muscles there's a little patch of exposed skin where he secretes his scent and that's used for marking territory and these boys are very territorial males will hold territory of around three hectares and they defend their territories quite adamantly they'll put up quite a fight against other male koalas they are in fact quite muscular animals despite looking kind of chunky it's all fur and muscle in 2019 australia had the hottest summer on record and the resulting bushfires were devastating to the koala population across the country fortunately the numbers lost during the bushfires turned out to be much lower than expected and reports of them being functionally extinct in the wild were exaggerated unfortunately koala populations have been in decline for years and in just the last three generations of koalas their numbers have declined by 28 they are a protected species but much of their territory isn't habitat degradation fragmentation and climate change exacerbating natural forest fires are their biggest threats as their continent continues to warm the days for australia's cuddliest marsupial may be numbered [Music] we loved spending time in the eucalyptus forest and it would have been so fun to look at koalas from up close our friends at nature on pbs are getting even closer to the action in their new miniseries spy in the wild 2. in this sequel to the popular spy in the wild series the team introduces more than 50 incredibly realistic spy cameras shaped as hummingbirds gorillas and even turtle eggs to allow them to record nature as you've never seen it before each episode explores a different region of the world my favorite episode so far transports viewers to australia where a spy koala cam is accepted by other koalas and films breeding behaviors up close and personal nature spy in the wild 2 is streaming right now at pbs.org spy in the wild with new episodes airing wednesday nights at 8 eastern time 7 central on pbs through may 20th be sure to stream all the episodes on the pbs video app so that you don't miss a single species what should i talk about next please let me know in the comments and be sure to subscribe for new episodes of animal logic every week thanks for watching oh this one's this one's peeing as one does

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Views: 1,078,208

Rating: 4.8890815 out of 5

Keywords: animals, animal, logic, education, show, animalogic, crazy, ugly, weird, gross, beautiful, interesting, facts, animalsfacts, about, information, info, school, research, learn, learning, fun, easy, smart, koala, drop bear, bear, australia, marsupial, eucalyptus, poison, venom, toxin, toxic, koalas have guts of steel, metal, trees, sloth, slow, sleep, sleepy, old man, wet koalas, wet koala, grumpy

Id: 9DVGqXaaCMY

Length: 13min 26sec (806 seconds)

Published: Fri May 15 2020