There’s a new animal at the local zoo: a Masai giraffe calf! The son of mom Amari and dad Chad (A+ giraffe name), the little giraffe seems to be healthy and thriving.
As I read the exciting news, I was struck by the word ‘Masai.’ What is a Masai giraffe? Is it different from a regular giraffe? The answer is…complicated.
But first, some basic giraffe facts!Giraffes (Giraffa camelopardalis) are Earth’s largest land animals. They are African mammals with very distinctive long necks and spots. In fact, early humans thought that giraffes were a mix of a camel and a leopard – that’s how they got the name camelopardalis!
Okay, so are there different species of giraffes? Probably! Giraffes were traditionally classified as a single species with nine different subspecies. The term ‘subspecies’ refers to populations of a species that live in different areas and vary in physical characteristics like size and coloration but that can still successfully interbreed. However, DNA evidence suggests that some of these giraffe subspecies are different enough genetically to be considered separate species. The IUCN, though, still classifies giraffes as being a single species.
But if you prescribe to the idea that there are multiple giraffe species, you’re looking at 4 different ones: northern giraffes (C. camelopardalis), southern giraffes (G. giraffa), Masai giraffes (G. tippelskirchi), and reticulated giraffes (G. reticulata). Each species lives in different parts of Africa and have different coat colorations and patterns. For example, Masai giraffes have oak leaf-like spots, while reticulated giraffes have dark coats with a web of narrow white lines.
Putting size in perspective
It’s easy to say that giraffes are tall, but let’s look at some hard numbers.
Giraffes start their lives with impressive height: calves are around 6 feet tall at birth. And they only get bigger – calves can grow about an inch daily during their first week of life! Female giraffes (called cows) get to be around 15 feet (4.5 meters) tall; the males (called bulls) max out at about 18 feet (5.5. meters).
A giraffe’s height gives it an advantage when looking for food. Unlike other animals, which can only reach foliage on the ground or low branches, giraffes can graze from the tops of trees without competing against other grazers for food. With their 21-inch (0.5-meter) long tongue, giraffes can reach foliage almost 20 feet (6 meters) from the ground. This makes giraffes Earth’s largest pollinator: as they move from treetop to treetop, they spread pollen across the savannah with their faces.
But a giraffe’s height also has a disadvantage – it’s hard to drink! Their neck isn’t long enough to reach the ground when standing upright, so giraffes must spread their front legs to get closer to their water source. This might not sound like a big deal, but this puts giraffes in a potentially dangerous position. Giraffes stay safe in part because they can easily see predators coming. By bending down, they lose their sight advantage. In addition, giraffes avoid predators by either running away or kicking them. In this bent-over position, both actions are difficult to do. Drinking is basically the only time a lion or crocodile can easily kill a healthy adult giraffe.
But luckily, giraffes don’t have to drink all that often! They get most of their liquid from their preferred food source, the leaves of the thorny acacia tree. Still, during the dry season, they have to drink water every three days.
Large hearts
Because they’re so tall, giraffes have a long way to pump blood from their hearts to their brains. They’ve partly solved this problem by having a large, extra-strong heart. Giraffe hearts are approximately 2 feet (0.6 meters) long and weigh about 25 pounds (11.3 kilograms). This is about the size of 50 human hearts! Giraffe hearts have thick, muscular walls that drive blood to a giraffe’s brain. In addition, giraffes have thick-walled arteries in their necks, complete with extra valves to help counteract the pull of gravity.
But what about when giraffes bend down to drink? You don’t want blood suddenly rushing into your brain! To avoid catastrophic blood pressure changes, giraffes have evolved special capillaries at the base of their brain to help control the speed at which blood flows. These capillaries also have one-way valves to further control blood pressure.
A final blood pressure issue is how to circulate blood from the feet all the way up to the heart. Giraffes have solved this by evolving tight skin on their legs that serves as compression socks.
Thick necks
Giraffe necks are more similar to ours than you may have thought: like us, giraffes have just seven bones in their necks. But that’s where the similarities end! These neck bones, or vertebrae, are only half an inch (1.27 cm) long in humans but are 10 inches (25.4 cm) long in giraffes. If you do the math, this means that giraffe necks can be about 6 feet (1.8 meters) long!
Beyond reaching food, these long necks are important in establishing mating rights and hierarchies within a giraffe herd. Male giraffes will engage in ‘necking’ – hitting each other with their long necks. These battles usually aren’t fatal, with the loser often retreating before lasting damage is done. But if there’s a large enough hit, the loser can be knocked out or even killed.
In addition to their necks, male giraffes will spar with their ossicones. Ossicones are the two hair-covered horns on top of a giraffe’s head. While both males and females have two ossicones, males often appear to have more. This is due to calcium deposits that form in their skull to protect themselves when headbutting other males.
Giraffe naps
It turns out that giraffes don’t need much sleep! These animals can survive on just 5 to 30 minutes of sleep a day. Giraffes sleep in short bursts of 1 – 2 minute naps throughout the day. They can even sleep standing up!
Why do giraffes sleep so little? One reason is that they need to spend a lot of time grazing. A large male giraffe can eat about 145 pounds (65 kilograms) of food every day! But because they have to eat around the thorns of acacia trees, giraffes typically only get a few leaves in each bite. As a result, giraffes usually spend 16 – 20 hours a day eating.
Side note: this large amount of time spent eating may explain why giraffe tongues are black! A giraffe’s tongue spends a lot of time in the hot African sun grabbing leaves. Dark coloration may help provide natural protection from the sun’s rays. Their thick, sticky saliva also helps protect their throats from any thorns they might swallow.
Baby time
Giraffe calves have a rather rude awakening to the world. Female giraffes give birth standing up. And since giraffes are rather tall, the first thing calves encounter out of the womb is a 5-foot drop to the ground. The umbilical cord is only 3 feet long, so it snaps about halfway down.
But don’t worry! Giraffe calves aren’t hurt in this free fall. In fact, the impact of hitting the ground helps the calf take its first breath. Within half an hour, the calf can stand; after ten hours, it can run around with its mother.
Giraffe calves and mothers spend their first week after birth learning each other’s scents. But by the time the calf is a month old, it and its mother have rejoined the giraffe herd. Within the herd, the calves will group together into a nursery, with their mothers taking turns looking after all the calves during the day. This allows a mother to travel up to 200 meters away from her calf to find food. But don’t worry – she returns every night to feed and protect her calf!
But can they swim?
I know this is a burning question you all had!
Until quite recently, giraffes were thought to be the only mammal in the world that couldn’t swim. Between its spindly legs that couldn’t provide purchase in the water and short body with a long neck that couldn’t be very buoyant, scientists thought swimming was virtually impossible for giraffes.
But this is why I love science: a 2010 paper in the Journal of Theoretical Biology used a digital model to prove that giraffes could swim!
To be clear, I don’t think swimming would be fun for a giraffe. Its neck would have to be at a pretty awkward angle to keep its head above the water. And it probably wouldn’t get much power from its legs. You can read more about the research here.
So while you may never get as tall as an adult giraffe, you can rest assured that you will likely be a better swimmer!
Resources
Leave a Reply