Walruses

Alex Re (00:00): Hello, welcome to On Wildlife. I'm your host Alex Re. On this podcast, we bring the wild to you. We take you on a journey into the life of a different animal every week, and I guarantee you you're going to come out of here knowing more about your favorite animal than you did before. This week I'm going to be talking about an animal that exemplifies the word large through their bodies, their tusks and their appetites. They also have tons of unique adaptations that help them survive in the wild that I can't wait to tell you about. Unfortunately, these adaptations have also made them a target for humans, so make sure you bundle up because we're heading to the poles of the earth to talk about walruses.

(01:02): Walruses are part of a group known as pinnipeds. This group also includes sea lions and seals. Pinniped means fin or flipper footed, and this group is separated into three types. Ear seals, also known as s airless seals, also known as faucets and walruses known as Odos. Odos were the second family to evolved after OTAs, which is why they have the ability to walk on their front flippers like legs. Faucets do not have this ability. Walruses are the only living members of the family Odobenidae their closest relatives when extinct during the Pleistocene era, walruses live in the Arctic and Subar regions, which includes the northern Pacific Atlantic and arctic oceans. They live in Antarctica as well. Although they inhabit these oceans, they prefer to stay in coastal areas or near ice flows. Walrus is very rarely travel to waters that are more than 260 feet in depth, but they can dive up to 300 feet below the surface and can stay underwater for 30 minutes.

(02:15): They rely heavily on ice sheets that cover the oceans, and during times when there's not a lot of ice, they'll hang out on beaches waiting for it to come back. There are two subspecies of walruses. The Atlantic, walrus and Pacific Walrus and walruses are absolutely enormous animals. A male can reach up to 12 feet in length and weigh almost 4,000 pounds out of the two species. Pacific walruses tend to be a little bit larger than Atlantic, and males also tend to be one third larger than females in both weight and tusk size. Although they're large, walruses can move pretty fast both on land and in the water when they need to. While on land, they can easily stay on pace with an adult human running at full speed in the water. They usually move very slowly about four miles per hour, but they can kick it into high gear to swim at 22 miles per hour.

(03:13): Something that makes walruses truly unique are their huge tusks. Walrus tusks are actually just massively overgrown upper canine teeth, but they don't help them eat. These tusks can grow up to three feet in length and weigh over 12 pounds. The main functions of these tusks are in mating displays, territorial disputes, defense, and aiding the walrus in hauling itself out of the water. Walruses usually live between 20 and 30 years in the wild, but they've been known to live for over 40 years in some cases. But what and how do they eat? We'll talk about that right after the break. The science word that I want to talk to you about today is lymphocyte. A lymphocyte is a type of white blood cell in your body that helps you fight off diseases.

(04:25): Okay, now back to the episode. As I previously stated, walrus tusks have no real function in eating or finding food. Instead, the most important tool a walrus has to find food is its whiskers. They demonstrate a behavior called rooting when in search of food where they'll shove their face and whiskers into the ocean floor to disturb and dig up organisms. When a food item touches a walrus whiskers, which are also known as vibra, the walrus can actually sense that it's there. Then the walrus can eat the prey, and because of this, they're classified as forages. Walruses feed mostly on shelled organisms like mus clams and other mollusks, but they have been observed eating sea cucumbers, coral shrimp, crabs, tube worms, fish and squid. This means that they're carnivores. In much rarer cases, walruses have also been observed feeding on whale carcasses and even small seals and narwals trapped in the ice.

(05:29): Walruses demonstrate a really cool feeding behavior when they eat shelled organisms like clams. When a walrus finds a clam, it will create a watertight seal around the edge of the shell with their mouth. Once the seal is in place, the walrus will press its tongue against the clam and then quickly withdraw it. This creates a very strong suction force that sucks the clam out of its shell. A walrus can eat over a hundred pounds of invertebrates every day. Walrus are very social creatures and are gregarious in nature, which just means that they live in groups. Groups of walrus can range from very small with just a few individuals to over a thousand individuals. A group of walruses is called a herd, and when they're not in breeding season, females and males tend to stay in separate herds based on their sex making the herds much smaller, and not only are they very social, but there's a very clear dominance hierarchy demonstrated throughout the individuals of the herd.

(06:33): The main factors that determine an individual's place in the social hierarchy are tusk length, overall size, and displayed aggression. The dominance hierarchy pertains mainly to the males as they're the aggressive ones. In order to communicate with each other, they can use a whole bunch of different sounds. They growl, bellow, and even bark. A walrus bellow can be heard over a half mile away and they actually don't use vocal cords to produce this sound. To do this, they have air sacks in their pharynx. During the breeding season, which occurs from December through March, males will have a whole harem or a group of females that they'll share their territory with. A dominant male will meet many times with all of the females that he claims in his territory. Studies have shown that on average the male to female ratio in these territories are one male to around 23 females.

(07:32): Walruses are really interesting because unlike other species of pinnipeds, they don't have or defend terrestrial breeding grounds. A walrus territory is fully in the water as that's where all the breeding takes place. Male and female walrus reach maturity at different ages. Like many other species, female walruses will mature between ages six and seven. While males mature between eight and 10, young males are not very effective in territorial disputes or mating until they reach around 15 years old because as I mentioned earlier, dominance is based on size. A younger walrus is inherently smaller in body and tusk size, which makes territorial disputes with much older males A lot harder. Territorial disputes are settled with battles known as Tuscan, and many males have scars from past battles. This is basically where males will fight each other using their tusks. Bouts of ting between two males competing for a mate or a territory can get very violent and often end in injury, but are very rarely fatal.

(08:43): Although many adult males have scars on their bodies from territorial disputes, they're just superficial injuries. Part of the reason why these fights only cause minor injuries is walrus skin is incredibly thick. For us, getting pierced by a walrus tusk would cause some serious damage, but not for them. Walrus skin is usually up to one or two inches thick and is deeply folded around the shoulders and neck where the majority of the tusk takes place. Each mating display that a male makes, lasts around three minutes and consists of him displaying his tusks and making key sounds described as pulses, clicks, teeth, clacking whistles, and clanging bell like sounds, displays will take place both above and below the surface of the water, and whistles happen mainly above the water. Males will display to resting females in an attempt to court the female enough so that she'll join him in the water.

(09:45): Because the entire process is underwater in pretty remote locations, it's hard to observe, so not much is known about the actual mating process. Once mating is done, the female has a pretty long gestation period ahead of her. The average female is pregnant for 15 to 16 months. This extremely long gestation period is due to a process known as delayed implantation. This reproductive strategy is where the embryo does not immediately implant in the uterus and is maintained in a state of dormancy. Animals utilize this strategy in order to make sure they give birth in the right conditions. When the female gives birth, she'll move away from the rest of the herd. It's believed that they do this so they avoid predators attracted to the herd or prevent their calves from being crushed by other individuals. When a walrus pup is born, they weigh a whopping 130 pounds.

(10:46): Walrus pups will stay by the mother's side for around two to three years, and during this time, the mother will not interact with any other males or have more pups. Something interesting about walruses considering how huge they are, is that they get startled pretty easily and they've been known to stampede. Stampedes can end in death for members of the herd, so they're really dangerous. Walruses, like many other Arctic animals also require breathing holes in the ice surface during the winter and have been observed using their tusks to keep these holes open. Walruses also have a long history with humans, and we'll talk about that right after the break time for our trivia question, where would you find a gems Bach in the ocean? In a lake, in a Savannah, or in a rainforest? You would find it in a Savannah because it's a species of antelope.

(12:10): Walruses and humans have become pretty familiar with each other over the years. Walrus are highly valued in all cultures of the Arctic Circle as an extremely important source of food and other resources like weapons and tools. These cultures would use the ivory and bones from walrus to make different things. They would use the blubber for lamp fuel and the skin as blankets, canoe, coverings, or clothing. They have also been documented in both modern and historical cultures to attack humans and boats. While they have been known to do this, they're not outwardly aggressive and can even be friendly, but for some reason they really like to attack watercrafts. There's a lot of interesting practices that these cultures had when it came to walrus hunting. Some cultures would not use materials that they use to hunt walruses for any other animals highlighting the sanctity of hunting walruses.

(13:07): Walruses have also been subject to severe poaching and overhunting, especially when there started to be a demand for walrus ivory in Europe. In the 18 and 19 hundreds, they were hunted to near extinction and this is seen in their diminished numbers today. Luckily, poaching walruses in the modern day is much rarer and only certain people have special permission to hunt them. There are around 250,000 walruses left in the wild, which is a decline from their numbers in the past. Hunting isn't the only thing that's hurting walrus populations, though climate change plays a huge role too. As the earth gets warmer, the sea ice that the walruses rely on begins to melt. This means that they're forced to live on small pieces of land, and when they do this, they're usually extremely overcrowded. This can lead to diseases or individuals just being trampled to death, and it's really important that we preserve walrus because they're a major player in the Arctic ecosystem and they're even regarded as a keystone species because of their foraging behavior.

(14:16): When they root around in the sediment to find food, they stir up a lot of the ocean floor. When they do this, they release a lot of decomposing organic material that otherwise would've been trapped under the sediment. By doing this walruses speed up the cycling of nutrients, the excess of nutrients that they release affects all levels of the food chain from a boom of phytoplankton, which supports populations all the way at the top of the food chain. In short, walruses take a relatively unproductive ecosystem in the Arctic and makes it extremely and prolific. Walruses also support their ecosystem in a smaller way as prey animals. For two species, the polar bear and the orca, there have been instances in which polar bears will hunt walrus, but this isn't very common as they're not easily taken down and will fight back and could possibly kill a polar bear.

(15:13): Orcas are much more likely to hunt and kill walruses, and at that point a walrus stands really no chance. So as you can tell, walruses are crucial to the Arctic and Antarctic ecosystems. If you want to help them, you should check out Oceana Defenders of Wildlife and W W F Arctic. Thank you so much for coming on this adventure with me as we explored the world of walruses, you can find the sources that we use for this podcast and links to organizations that we reference at onwildlife.org. You can also email us with any questions at On Wildlife dot podcast@gmail.com, and you could follow us on Instagram at On Wildlife or on TikTok at wildlife. Don't forget to tune in next Wednesday for another awesome episode, and that's on Wildlife

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