Adolescence and the development of social behaviour in giraffes

Young giraffes' social lives are not simply about meeting as many giraffes as possible. Adolescents repeatedly associated with particular kinds of companions, especially other adolescents of the same sex. Growing up appeared to involve selective company, not a general drive to join the widest possible circle.

Zoe Muller, Innes Cuthill and Stephen Harris observed two enclosed wild giraffe populations in Kenya for nine months each. The populations contained 77 and 89 animals, including 36 adolescents in total, aged roughly one to four years. The researchers recorded group membership and compared both the number of different associates and the frequency of meeting them. Randomised comparisons accounted for when and where animals were available to meet.

In both populations, male and female adolescents had their strongest repeated associations with same-sex peers. Associations with adults of their own sex also featured, although individual comparisons differed between sites. Female adolescents did not meet more animals than expected by chance; males sometimes met fewer. These observations cannot establish that companions taught each other skills, as the researchers proposed. They do identify a distinct stage of social development: young giraffes were not merely mixing at random while waiting to become adults.