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
Nubian giraffe by Swedish zoologist Carl Linnaeus in the "Systema Naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis" in 1758. He described the giraffe from Ethiopia or Sennar of Eastern Sudan. A 2016 analysis of giraffe subspecies proposed the Rothschild's giraffe ("G. c. rothschildi") could be considered a conspecific ecotype of the Nubian giraffe, however these results are not definitive. Following Linnaeus's description of the Nubian giraffe, several specimens were described by other naturalists and zoologists since the end of the 18th century under different scientific names, which are all considered synonyms of "Giraffa camelopardalis