Giraffe up to , and can sustain for several kilometres. A giraffe rests by lying with its body on top of its folded legs. To lie down, the animal kneels on its front legs and then lowers the rest of its body. To get back up, it first gets on its knees and spreads its hind legs to raise its hindquarters. It then straightens its front legs. With each step, the animal swings its head. In captivity, the giraffe sleeps intermittently around 4.6 hours per day, mostly at night. It usually sleeps lying down, however, standing sleeps have been recorded, particularly
Giraffe living giraffes consist of multiple species. The researchers suggested the existence of four species, which have not exchanged genetic information between each other for 1 million to 2 million years. Those four species are the northern giraffe ("G. camelopardalis"), southern giraffe ("G. giraffa"), reticulated giraffe ("G. reticulata"), and Masai giraffe ("G. tippelskirchi"). Since then, a response to this publication has been published, highlighting seven problems in data interpretation, and concludes "the conclusions should not be accepted unconditionally". In 2016 there were an estimated 90,000 individuals of "Giraffa" in the wild. In 2010 there were more than 1,600 in captivity at