|Author(s)||Cecilie Grønlund Clausen|
In this study, I have investigated the social structure of a population of the Southern giraffe (Giraffa camelopardalis giraffa) residing in Pilanesberg National Park, South Africa. To do so, association data was collected using photo-identification to recognise individual giraffes. Within the study period between October 27th 2012 and January 25th 2013, 257 groups of giraffes were encountered, and the population number was estimated to be at least 173 giraffes residing within the 513 km2 area. For the analysis of the social structure, data was restricted to only include individuals that were identified 5 times or more (n = 90) to strengthen reliability of the data. Sociograms depict a highly interconnected population, and results thus suggest that it exhibits fission-fusion dynamics, as individuals frequently move between groups. I investigated the patterns of association within the entire population along with different subsets of the data, so that I could study the possible differences in association patterns within the sexes and within age classes. I found that the giraffes exhibited non-random patterns of association in all subsets of the data, which means that the structure of the populations is a result of preferred and avoided relationships between its individuals, despite sex and age. Cluster analysis further revealed the presence of cliques, which are collections of individuals which are more prone to associate with one another, than they are with any other individuals in the populations. Network metrics revealed that adult females were the most sociable individuals in the population, and therefore have the biggest influence on the social structure, whereas males and in particular juveniles were less sociable, and occupy peripheral parts in the network. Sociability was also revealed to differ between age classes within the male network, suggesting that older males are more solitary and younger males to be more social.
Keywords: Southern giraffe, Social Organisation, Social Behaviour, Ecology, Distribution
Author: Cecilie Grønlund Clausen
Journal: Master Thesis