Giraffes are the world’s tallest terrestrial mammals. Through battles between individuals, evolution has favoured a strong and robust neck and this has given the giraffe the opportunity to feed from places other animals, except elephants, cannot reach.
Giraffes can reach a height of almost six metres and an adult male can weigh close to two tonnes.
There are eight subspecies of giraffe and they all belong on Africa’s savannahs. The giraffe can efficiently defend itself against lions and other predators by violent kicks with the forelegs.
The giraffe eats nutrient-rich plant parts, such as leaves, buds and bark from trees and bushes, acacias in particular. Thanks to its height and its 40 cm long tongue, the giraffe can easily reach the leaves high up in the acacia tree and the sharp thorns are skilfully avoided.
The giraffe can live for 25 years in the wild and somewhat longer in zoos.
Like most other large animal species the giraffe is today mostly found in reserves and other protected areas. The main threat today is poaching and loss of habitat caused by humans.
The mating can occur at any time during the year, but is most common during the dry months. The gestation period is 14–15 months. Normally a single calf is born. It is around two metres tall at birth and can stand up when only 20 minutes old.
The thinner lower legs have very thick skin that works like an “anti-G-suit” of the kind pilots of supersonic planes wear. This lessens the influence of gravity on the blood flow.
The blood pressure in the large arteries of the neck is almost the double of a cow’s, but despite this, the pressure is normal when it reaches the brain. This is thanks to a network of capillaries whose many branches decrease pressure changes to the brain, which would otherwise be injured simply by the giraffe bending forward!
2 metres above the hooves and 3 metres below the head is the heart situated. A physiological body plan like that demands some special adjustments in order to work. More about that in the box next to this.