Giraffes live alone or in loose groups. Young male giraffes foa single baby, which is called "calf". Giraffes give birth while standing, so the baby falls down 2 metres. Giraffe calfs are already 2 m tall and weigh 50-55 kg. The calf stays with its mother for 1½ years. Young giraffes become mature when they are 4 years old, and they are fully grown when they are 6 years old. Giraffes can live to 25 years old, and in captivity they can live 35 years.