Animal Spotlight: Giraffe
Giraffes tower over the plains of Africa, the tallest land animals on earth, gentle giants, the watchtowers of the savannah, beautiful to behold. They are awkward but strangely graceful. And their striking appearance is matched by striking adaptations in their anatomy and physiology.
Giraffes are known for their long necks and long, spindly legs. Adult male giraffes are about 16–17 feet tall — way higher than a basketball hoop! — and weigh about 2600 pounds — as much as a small car! Females are about 2 feet shorter and about 800 pounds lighter than the males. Both males and females have irregularly spotted coats, short, brown manes on their necks, hooves on their feet, and long, black hairs at the ends of their tails.
Horn-like protuberances on the tops of their heads, called ossicones, are relatively soft when the giraffe is born, but turn to bone and fuse to the skull as the animal ages. Ossicones are more prominent in males. And giraffes have very large eyes and very good eyesight for scanning the savannah for predators.
Giraffes come from Africa, where they live in habitats ranging from open plains to dense forest. Because their natural habitat is threatened, wild giraffes now live in protected reserves, largely in the eastern and southern regions of the continent.
Giraffes browse on a variety of plants, but their favorite is the acacia tree, which they happily gobble up, 3-inch thorns and all! How do they avoid injuring themselves with those thorns? Giraffes’ tongues are very long — up to 21 inches — and maneuverable, and they often use their tongues to pluck the acacia’s leaves away from the thorns. When they do eat the thorns, their tongues and mouths are protected by a very thick layer of saliva. If you participate in a giraffe feeding at a zoo — such as the Giraffe Encounter at the Reid Park Zoo — you might get to feel a bit of a giraffe’s saliva for yourself!
Giraffes get most of the water they need from their food, but they do sometimes drink from waterholes. A giraffe’s neck can’t reach the ground while the animal is standing up, so to drink water, the giraffe spreads its front legs very far apart to lower the front of its body. That stance lets the giraffe’s tongue reach the water alright, but it leaves the giraffe vulnerable to predators, so it’s a good thing giraffes can go a long time between drinks!
Giraffes have evolved amazing adaptations to accommodate their long necks and legs. A giraffe’s heart has to pump out blood at very high pressure to get the blood up that long neck to the giraffe’s brain — a pressure that would be dangerous in humans. Giraffes have special genes that protect them from the organ damage that their high blood pressure otherwise would cause. They also have very tight, tough sheaths, like compression stockings, that wrap around the legs and help them to avoid another effect of high blood pressure, swelling in the feet and legs. Giraffes also have special features in the arteries and veins in their necks that prevent too much blood from rushing to their heads when they bend down to drink and too much blood draining out of their brains and making them lightheaded when they raise their heads again.
The neck bones, or vertebrae, in giraffes are amazing, too. You might think that giraffes’ necks, being so long, would have a lot more vertebrae than humans’. Not so! A giraffe has 7 neck vertebrae, the same number as us. An amazing difference, though, is in the height of those vertebrae — each giraffe vertebra is about 10 inches tall — about 10 times the height of a vertebra in you or me. You might get to see a model of a giraffe vertebra when you visit the Reid Park Zoo.
Giraffes are social, but not territorial. They live in groups of a few animals to several dozen. The groups include both males and females, unlike some other social animals, such as lions. The membership of the group changes constantly as individual animals join and leave it. A group of giraffes can be called a herd, as for other animals, but do you know the special name that’s used just for a group of giraffes? A tower! What a good word for the tallest animals on earth!
Because of their size and their ability to deliver lethal kicks, giraffes have few natural predators — mainly lions, hyenas, and wild dogs. In fact, a tower of giraffes, scanning the savannah with their amazing visual abilities, often provide a safe grazing area for smaller animals, since the giraffes will spy predators first and alert immediately. Giraffes are vulnerable to predators when they sleep, so they spend little time sleeping, often just 20 minutes a day! When they do sleep, they usually tuck their feet under them and rest their head on their hindquarters, but they can also sleep standing up for short periods.
Giraffes are “precocial” — a newborn calf is much more mature than a lion cub or a human baby. Giraffe calves are about 6 feet tall and 150 pounds at birth, and newborn giraffes can stand up and walk within an hour. Calves usually nurse for about a year. Giraffes live for 10–15 years in the wild, and over 30 years in human care in zoos.
The Reid Park Zoo has been home to wonderful giraffes over the years, and the giraffes are a favorite stop for Zoo visitors. Four giraffes currently live at the Zoo. Denver is a female and the oldest of the tower at 32 years. In fact, Denver is the second-oldest giraffe in the country! Jasiri, a male, is next oldest and in his prime at 10 years. And the Zoo welcomed two youngsters to its giraffe tower in the fall of 2020. Penelope, a female, is 2 ½ years old and was 11 ½ feet tall on her second birthday! Sota, a male named for his home state of Minnesota, is about a year younger than Penelope, and he was already over 10 feet tall on his first birthday! These towering creatures will probably be very interested to see everything — and they’re probably the only ones in the Zoo who can — happening with the Reid Park Zoo expansion!
Humans are the major threat to the survival of the giraffe species, because of hunting and because of loss of the giraffes’ natural habitat to human development and climate change. The number of wild giraffes has dropped about 40% in the past 30–40 years, to fewer than 100,000 animals. The IUCN classifies giraffes overall as Vulnerable, but two of the four identified species of giraffe, Reticulated (the giraffes at the Reid Park Zoo) and Masai Giraffes, are classified as Endangered. Members of the Association of Zoos and Aquariums, such as the Reid Park Zoo, help to fight the loss of giraffes through the Giraffe through the SAFE program.
A last fun fact: World Giraffe Day comes every year on June 21 st- it’s on the longest day of the year, to honor the earth’s tallest animal! How about visiting the Zoo to wish the tower a Happy World Giraffe Day?
Originally published at http://reidparkzooexpansion.org on June 17, 2021.
