Because they are the tallest living land mammals, giraffes live a unique lifestyle in the dry savannas and open woodlands. Bulls forage on high tree branches while cows feed on lower ones which minimizes competition for food. Even though giraffes have record-length necks, they only have seven neck bones, or cervical vertebrae, the same as most other mammals, including humans. These vertebrae are greatly elongated to support their muscular necks.
Giraffes are browsers that prefer to eat new shoots and leaves of thorny acacia trees.
Adults forage throughout the day and remain standing to take several momentary naps. Occasionally they lie down but standing allows them to watch for approaching danger. Giraffe horns differ from those of other hoofed mammals because their bony protrusions are covered by skin and hair. These knobs are found on both sexes but are larger on males. They are an effective tool during combat when rivals sling their thick skulls at each other's necks.