Giraffes

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. On this episode, we're going to be talking about one of the largest land mammals in the world. They're an amazing example of how evolution works because of their unique adaptations, and they're also really important to the ecosystems that they live in. So you better look up because this week we're talking about giraffes.

(00:55): Giraffes can be found in Savannahs all throughout Africa. There are more found in the south of Africa than in the north, and there are four distinct species being the northern giraffe, southern giraffe, massage giraffe and reticulated giraffe. While there are four main species, there are also a number of subspecies. A subspecies is technically still the same species, but there are some genetic differences. It's thought to be the first step towards speciation, which means becoming a completely new species and while the different species could possibly breed if they met in the wild, this is very unlikely because all the species and subspecies inhabit completely different locations with very little overlap. The main way to physically see the difference in these species is by looking at the shape of their brown spots, the darkness or lightness of their coat and their size. The smallest is the northern giraffe, and they also have very light spots, and the largest species is the messai giraffe, their closest relatives, and the only other animal in the family giraffe a day is the okapi, which first began to evolve around 2 million years ago.

(02:09): In Tanzania, okapi are really cool looking animals. They look like a mix between a zebra and a donkey, but they have those two distinct horns sticking out of the top of their heads just like giraffes do. Giraffes are the tallest land animal that currently lives on the planet and they can reach heights over 18 feet for males and 14 feet for females. That's around the height of a two story house. Because they're so tall, they also weigh a lot. The males can weigh almost 4,500 pounds when fully grown, even the females can get over 2,500 pounds. There are around 120 giraffes left in all of Africa, and many subspecies are critically endangered, but we'll talk about that later on in the episode. They also live for about 30 years in the wild and even longer in captivity. Because these animals are so massive, they have to eat a huge amount of food every day.

(03:08): Giraffes are herbivores so they only eat plants, and adults can eat up to 145 pounds of vegetation every day. That takes a lot of time, so they spend the vast majority of their day eating and will even snack throughout the night. They only sleep for about four and a half hours. Specifically, their favorite food is leaves from the thorny acacia tree and they like to eat the newer leaves because they're easier to forge and also have a lot more nutrients. Acacia trees have thorns all over them as a defense mechanism, but giraffes have figured out a way to work around this. Their tongues, interior mouth and lips are covered in thick tissues to make the thorns not hurt as much, and both their lips and tongues are prehensile, meaning they can move and be used as an extra arm. They can literally wrap their tongue around a branch as if they were grabbing it with a hand.

(04:06): Their tongues can be 21 inches long, which lets them reach branches on trees that are taller than they are. Giraffes aren't too picky though. When food is scarce in the fall, they'll eat pretty much any plant that they can find, but when summer comes around and every plant is in full bloom, they're a lot more selective. There have been observations that females also known as cows tend to select more high energy food when they forage, probably because they need more energy to carry and deliver. A baby. Africa can get to be pretty hot, which means it's important to be getting a lot of water in your system and most of the water that giraffes need is gained through what they eat. When they can find actual water, they'll definitely drink that, but it's not so easy to come by. They can be healthy drinking water every three days. Now, one of the most identifiable features of giraffes are their long necks, and I'll tell you all about them right after the break. This week I want to give a shout out to Quentin from Florida. His favorite animal is a wolf. Did you know that wolves have 42 teeth? That's 10 more than we have. If you want me to give you a shout out on the podcast, send an email to on wildlife dot podcast@gmail.com telling me your name, where you're from, and your favorite animal.

(05:49): Okay, now back to the episode.

(05:53): Giraffes bodies are shaped like one long slope from their hindquarters all the way to their head, and there's a reason for this. Their neck is really long and having a larger base helps them keep their balance. The vertebrae of their upper back also have long spines, which are used as strong attachment points for the muscles of their neck, which gives them more support. And just like humans, giraffes have seven vertebrae in their necks, but they're extremely elongated and can be as long as a foot, but the vertebrae aren't connected in the same way that human vertebrae are. They're connected with ball and socket joints. These are the same joints that connect the bones in our shoulders, so as you can tell, that gives their necks a whole lot more flexibility than ours, but their necks also give them a lot of problems, especially with their circulatory systems.

(06:47): If giraffes had a normal circulatory system, they would have a really hard time getting blood to flow to their heads because it's a long way up. Because of this, they have extremely thick arteries and they have valves in those arteries to prevent blood from flowing the wrong way. Also, they need to make sure that they're getting enough blood flowing to their brain, which is why they have a lot of blood vessels at the base of their brain to control blood pressure. Their necks also tell an interesting story of evolution. A famous biologist named John Baptiste Lamar used giraffes necks as a way to explain how he thought evolution worked. He thought evolution was driven by inner need of animals. His hypothesis was that because giraffes wanted to eat leaves from tall trees, they stretched their necks more and more over time, and because of this over many years, their necks grew.

(07:41): We now know that's not how evolution works. Now we know that giraffe ancestors that had longer necks were able to get food more easily than the ones that had shorter necks, so they survived and passed their genes onto the next generation. Over time, longer and longer necks were selected for especially because no other large land animal was able to reach the leaves that giraffes could giraffes walk in a way that is called a pace. This means that while they're walking, both legs on one side move simultaneously, and we just talked about this in the house cat episode. This changes when the giraffe is running, though the giraffe will push off its hind legs and the front legs will come down almost together, but there will never be both hind and front legs on the ground at the same time, and even though they look a little awkward while they're running, they're actually pretty fast.

(08:35): Giraffes can reach speeds of almost 40 miles per hour at top running speed, and they can maintain a speed of 30 miles per hour over long distances. That running speed comes in handy when trying to escape from their top predators. Lions, giraffes are at their most vulnerable when they're drinking water and there have actually been observations of crocodiles taking advantage of this and preying on them. Although adults don't have a lot of predators, they're young or heavily preyed upon by animals like hyenas lions. Like I said before, wild dogs and leopards giraffes will defend themselves by kicking and their kicks are extremely powerful and can even break bones, and you would think that such a big animal would stick out in the Savannah, but their spots actually provide them with really good camouflage. The color of their spots match really well with the color of the landscape.

(09:33): Their spots are also effective in helping keep them cool. Each spot has a lot of blood vessels underneath the surface of their skin, and giraffes can run blood through these blood vessels to release heat and reduce their body temperature. Female giraffes start reproduction at around four to five years of age, and because they're so large, they have a relatively long gestation period of around 15 months. Remember that our gestation period is only nine months. Breeding can happen at any time throughout the year, however, there is a tendency for them to be born during the dry months. They will give birth to only one offspring at a time, and these babies are massive. They're born already at six feet tall, weighing up to 220 pounds. Giraffes behave in an interesting way when it comes to their newborns. As soon as they're born, the mothers will take the baby to an isolated area where they begin to get familiar with each other's specific scent.

(10:35): After this week long period, the baby will be placed with similar aged individuals known as a nursery group and will leave their calves here while they look for food. This is not really a good system for caring for their young as they'll just leave them alone and defenseless for hours at a time, and because of this, almost half of all their offspring are killed by predators. If the mothers are around during an attack, they'll stand over their offspring and use their powerful legs to kick the predator. Newborns begin to eat vegetation as early as three weeks after being born, but they don't fully wean off their mother's milk for 18 months. Males will leave the nursery group to be with other males between the ages of one and two. While females will stay with the mother for much longer during their time with the other males, they'll engage in a behavior called necking.

(11:30): This is where males will repeatedly slam their heads and necks into one another because of these conflicts. Males will develop many protrusions from their skulls as each time they strike each other. It can cause minor damage. Necking is used to establish a social hierarchy between young males and also becomes a useful skill later in life. When bulls reach around eight years in age, they'll begin to wander and look for females who are ready to breed. They can travel up to 20 kilometers per day in their search. When two bulls come face-to-face in their search for a cow, they'll fight each other by necking. There have been reports of bulls knocking each other off their feet and even occasionally being knocked unconscious by this behavior. Okay, we're going to take our last break and when we get back we'll talk about some more giraffe behaviors. Time for our trivia question. What kind of animal would you see making a chrysalis? The answer is a butterfly chrysalis are similar to cocoons.

(13:02): Giraffes will live in groups of up to 20 individuals and are overall not very territorial animals. While giraffes are often observed in groups, they partake in a fission fusion society. This means that their social groups are constantly shifting in size and structure as they can separate and come together at any moment, and there's no defined leader of a herd of giraffes. Herding is an important behavior because it provides for more defense against predators, and giraffes have different sized home ranges depending on the area that they live in. If the herd lives in a wetter area, home ranges can be as small as 33 square miles, but herds found in drier areas can have an exponentially larger home range of up to 580 square miles. Giraffes have an amazing sense of smell, eyesight and hearing, and they use these senses for a few different things. Olfactory communication, which just means communication through scent, is thought to be a very important part of giraffe communication and social structure.

(14:09): Giraffes have been observed partaking in urine testing, and this suggests that scent is important in mating practices. Basically, males smell the urine of potential female mates to determine if they're ines or not, which means if they're ready to mate or not. If she's ready, then the male will start to court. The female giraffes have an extremely keen pair of eyes and actually have larger eyes than most other terrestrial mammals. Being inhabitants of wide open savannahs eyesight is extremely important in finding food mates, other individuals and predators. They can spot a predator from over a kilometer away, and when one individual starts to stare at a predator, all individuals in the group will also stare at them even less understood than their olfactory system is their sense of hearing as a way to communicate. Giraffes were first thought to be completely mute animals because early studies showed that they could not expel air at a high enough velocity to vibrate vocal chords.

(15:16): Now, they don't have vocal chords, but new studies show that they can make noise because they have a highly developed larynx. There have been multiple recordings of giraffes making snorting sounds, hises, low humming, and they're even capable of producing in infrasonic signals. In infrasonic refers to sounds below frequencies that can be heard by humans. Even though we know that giraffes can make sounds, we don't really know why they do it yet. One of the main reasons that vocalizations in giraffes are hard to study is because in captivity they don't really have a need to communicate with each other through sound. Giraffes are important to many other species that they share the savanna with. Many species like wildebeests, zebras, ostriches and impalas will use giraffes as alarm systems because they can see predators from much further away. Zebras have been observed reacting to certain giraffe vocalizations as warnings for a predator in the area, and there's even evidence that zebras are a lot calmer when they're around giraffes compared to when they're near other animals.

(16:24): Giraffes are also an important prey species for some of Africa's top predators, and one giraffe can provide a lot of food for those animals. Their diet also plays a pivotal role in the ecosystem because they're herbivores, they're great seed dispersers helping to distribute seeds throughout the ecosystem. There are even some acacia seeds that won't grow until they've passed through a giraffes digestive system. Unfortunately, as I said earlier, their populations are dwindling, and this is mainly because of habitat loss and poaching. People build farms where giraffe habitats used to be, and that creates two issues. First, it decreases the range of giraffes and can cause them to not have access to food or water. Second, it makes their interactions with humans more frequent, and giraffes can be considered pests because they'll eat some of the crops that farmers grow. If this happens, the giraffes could be killed.

(17:25): People also kill giraffes for their meat if there's not enough food. Luckily, there are organizations that are helping giraffes right now that you should definitely check out like the Giraffes Conservation Foundation, African Wildlife Foundation, and Save giraffes. Now, thank you so much for coming on this adventure with me as we explored the world of giraffes. You can find the sources that we use for this podcast and links to organizations that we reference@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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