One of our favourite giraffe facts is that they’re probably the biggest pollinators in the world thanks to their great height. As they wander around feeding from the tops of trees, they inadvertently transfer genetic material on their muzzles from the flowers of one tree to those of another.
How many bones do giraffes have in their necks?
Despite being incredibly tall, giraffes still only have seven vertebrae in their necks – which means a giraffe neck has the exact same number of bones as a human neck!
A giraffe at Hluhluwe-Imfolozi Game Reserve in South Africa. Jeremy Wade Shockley/Getty
How do giraffes drink when they’re so tall?
A giraffe’s neck is too short to reach the ground. As a result, it has to awkwardly shuffle and spread its front legs to reach the ground for a drink of water.
Fortunately giraffes only need to drink once every few days, as they can get most of their water from all the plants they eat.
A fully grown giraffe can raise or lower its head by up to 5m, so it might actually pass out were it not for a dense network of fine capillaries (the ‘rete mirabile’) that cushions its brain against rapid changes in blood pressure.
Other adaptations to prevent sudden giraffe collapse are valves to stop the back-flow of blood and elastic-walled vessels that dilate and constrict to manage flow. NASA has even done research on the blood vessels in giraffe legs to get inspiration for human space suits.
How many species of giraffe are there?
A study published in Current Biologyin 2016 suggests that the giraffe is not a single species, but a subfamily containing four distinct species – the northern giraffe (Giraffa camelopardalis), southern giraffe (Giraffa giraffa), reticulated giraffe (Giraffa reticulata) and Masai giraffe (Giraffa tippelskirchi).
To make this groundbreaking discovery, the team examined DNA taken from skin biopsies of 190 giraffes collected across Africa. This sampling included populations from all nine previously recognised giraffe subspecies, which may now be spread across four separate species.
The differences in each group’s genetic composition suggest that there’s little crossover between the various species, which implies that they must have evolved separately.
The giraffe genus (Giraffa) is part of the Giraffidae family, which contains only one other species: the rare okapi, the closest relative of the giraffe. This forest-dweller has a shorter neck, just like the extinct species from which both it and giraffes are thought to have evolved.
While the okapi’s black-and-white hind stripes might make you think of zebras, the resemblance is purely coincidental.
Want to find out more about okapi, the cousins of giraffes?
Unlike most other four-legged mammals like horses, giraffes swing both legs on the same side at almost the same time during their walk, known as ‘pacing’. Camels walk in the same way, and you’ll feel the sideways motion if you ever ride one.
When a giraffe breaks into a gallop, its odd walk disappears and it runs in a more ‘normal’ way.
How big are a giraffe’s hooves?
Giraffe feet are the size of a dinner plate with a diameter of 30cm. These huge hooves prevent giraffes from sinking into loose sand despite their great weight.
Until recently it was widely assumed that a giraffe’s long, spindly legs would not provide sufficient purchase in water to support its neck, and that the proportion of its elongated extremities to its short body would reduce buoyancy.
Therefore the giraffe was supposedly the only mammal in the world that could not swim (indeed, the authoritative Handbook of the Mammals of the World states bluntly that it cannot).
You might see a giraffe wading, but you won’t see one swimming. Ann & Steve Toon/Robert Harding/Getty
But this is probably wrong. A 2010 study in the Journal of Theoretical Biology used a complex digital model to prove that the average adult giraffe would, in fact, become buoyant in 2.8m of water.
Admittedly its heavy front legs would tip the animal forward, so to keep its head clear it would need to crank its neck backwards at an awkward angle, while the legs, swept to the rear, would have limited power.
So a giraffe could theoretically swim, but it would almost certainly never choose to, and it would be pretty terrible at it anyway.
If you’re wondering how you would even go about testing the bouyancy of a giraffe without a very large swimming pool or even a giraffe, have a read of this explanation by one of the study’s authors:
Both male and female giraffes have ‘horns’ at birth. More properly known as ‘ossicones’, they lie flat and are not attached to the skull to avoid injury at birth. They only fuse with the skull later in life.
Giraffe horns become formidable weapons in adult males, worn bare of skin at the tips – old bulls may even have patches of bare bone elsewhere on their massive, craggy heads.
A giraffe giving birth is a bit of a worrying sight if you haven’t seen it before – female giraffes give birth standing up, so the first thing a baby giraffe knows is a 2-metre fall to the ground. Despite the bumpy start, baby giraffes can stand up within an hour of birth.
Giraffes usually only have a single baby, born after a 15-month gestation period. But because they’re able to breed all year round, giraffes don’t need to ‘resynchronise’ with the seasons each time they give birth.
Sadly, about 50% of giraffe calves do not survive their first year.
Just like human fingerprints, no two giraffes have the same pattern. Researchers who spend long enough studying the same giraffes eventually find that they can recognise dozens or even hundreds of individuals from their patterns.
It’s thought that the pattern on a giraffe doesn’t just serve to camouflage the animal, but also helps with temperature regulation too. The coloured skin patches can act to dissipate heat around the body, as the temperature of the skin is slightly higher in darker regions, facilitating the dilation of vessels beneath the skin’s surface.
Giraffes also have an efficient nasal cooling system to regulate brain temperature up to 3°C lower than the rest of the body.
How long is a giraffe’s tongue?
Giraffe tongues are huge! They’re bluish-purple, prehensile and between 45-50cm long – perfect for carefully ripping fresh leaves from between the spikes at the top of acacia trees.
When fighting, male giraffes will push and shove against each other. This occasionally escalates into powerful blows delivered by their muscular necks. The loser can be knocked out, and sometimes even killed.
How big is a giraffe’s heart?
A giraffe heart can weigh approximately 11kg, making it the biggest of any land mammal. It can pump 60 litres of blood around its body every minute at a blood pressure twice that of an average human.
Giraffes mostly eat fresh leaves and twigs from the tops of trees (particularly spiky acacia trees) where other browsing species can’t reach them. That means giraffes can afford to be pickier than most big animals, and they’re also better able to cope with droughts than smaller animals, as the tallest trees tend to have the deepest roots that reach down to water that other trees can’t access.
But you might be more surprised to discover that the seemingly gentle giraffe also eats bones. Giraffes aren’t predators, so they don’t kill other animals, but their huge skeletons require more calcium and phosphorous than they can get from a strictly vegetarian diet. The easy solution is to chew the bones from carcasses to make their own bones stronger, a behaviour known as osteophagy.