Female giraffes are choosy and prefer to stay in groups with particular females, a new study reveals.

Researcher Kerryn Carter from The University of Queensland, Australia, observed the social groupings of 535 individually identified wild giraffes in Etosha National Park, Namibia, for 14 months.

She found that the giraffes have more complex relationships and social networks than previously assumed. "Giraffes show a fission-fusion social system, like humans, where individuals temporarily associate so that the numbers and identities of individuals in groups changes frequently," Carter said in a statement.

This kind of fission-fusion social system has been documented in other animals like the eastern grey kangaroos, bottlenose dolphins and northern long-eared myotis bats.

For the study, Carter looked at various factors like the frequency at which each giraffe pair met, how regularly they met and how much their home ranges overlapped. She noticed that female giraffes are choosy in selecting the friends they hung out with. "We found, rather than females interacting non-selectively as previously thought, individual female giraffes preferred to be in groups with particular females and avoided others," Carter said.

"Surprisingly, home range overlap and kinship together did not explain much about these female-female relationships."

Cater suggests that social preferences, giraffes' age, and their reproductive state might contribute to the selection of female friends.

She hopes that understanding the pattern of social networks could help in better management and conservation of the species. Further research on giraffes might also shed light on how individuals are able to learn about an environment from each other and how diseases spread through a population.

The details of the study have been published in the scientific journal Animal Behaviour.