The mammals is non-territorial and sociable, forming loose herds with no permanent members in very variable home ranges of between 5 and 650 square kilometres (3). Females tend to associate most with one another when they have young, as the calves tend to play together in crèches (3). Males leave their mothers at around three years, and sometimes form roaming bachelor herds that look for females (cows) in heat (3). Males spar with each other at all ages, standing side by side and swinging their necks to thump their head into the other male’s body. These fights can be quite gentle, or quite fierce, sometimes resulting in knocked-out giraffes (2). Mating occurs year-round, peaking in the rainy season, and results in pregnancies lasting 15 months. Females will usually become pregnant for the first time in their fourth year (3). The single calf begins life with a two metre drop, as females give birth standing up (8). The newborn calf is able to stand within 20 minutes and will grow about 2.1 metres in its first year. At a year old, young giraffes have been weaned but remain close to the female until at least 22 months old, often remaining nearby for life (3). Despite the females’ attempts to stand over their calves during attacks by lions, spotted hyenas, leopards and African wild dogs (4), many calves are killed in their first few months (3). Sexual maturity occurs at three to four years in both males and females, but males rarely have the opportunity to mate before seven years old (3). Life expectancy in the wild is 20 years (4).
Using its 45 centimetre prehensile, black tongue, the giraffe rips the thorny leaves from Acacia and Combretum trees and may eat as many as 100 other plant species (3). Reaching higher than any other mammal, the giraffe can eat up to 134 kilograms of leaves a day, and can ruminate whilst walking (3). These enormous animals do not migrate as they can obtain most of the moisture they need from their diet, but they will drink every two to three days when water is available. It is possible to distinguish the sexes from a distance as males more often extend their heads in line with their necks to reach branches higher than those the females are feeding from, with bent necks (5).
With strong eyesight from an elevated position and a good sense of smell, giraffes are often accompanied by zebra and wildebeest which may benefit from the giraffe as an ‘early warning system’ (6). Whilst it was thought that giraffes did not make any sounds, this is now known to be untrue, as giraffes bellow, snort, hiss and make flute-like sounds, as well as low pitch noises beyond the range of human hearing (3).