Résumé
The relationship between the spatio-temporal distribution of resources and
patterns of sociality is widely discussed. While the Resource Dispersion
Hypothesis (RDH) was formulated to explain why animals sometimes live in
groups from which they derive no obvious benefits, it has also been
successfully applied to species that benefit from group living. Some
empirical tests have supported the RDH, but others have not, so
conclusions remain equivocal and further research is required to determine
the extent to which RDH predictions hold in natural systems. Here, we test
four predictions of the RDH in an African lion population in the context
of their fission-fusion society. We analyzed data on group composition of
GPS-collared lions and patterns of prey availability. Our results
supported the first and second predictions of the RDH: home range size (i)
was independent of group size and (ii) increased with distance between
encounters with prey herds. Nonetheless, the third and fourth RDH
predictions were not supported: (iii) the measure of resource
heterogeneity and (iv) resource patch richness measured through prey herd
size and body size had no significant effect on lion group size. However,
regarding the fourth prediction, we added an adaptation to account for
dynamics of fission-fusion society, and found that the frequency of pride
fission increased as group size increased. Our data set restricted us from
going on to explore the effect of fission-fusion dynamics on the
relationship between group size and patch richness. However this should be
investigated in future studies as including fission-fusion dynamics
provides a more nuanced, realistic appreciation of lion society. Our study
emphasizes the importance of understanding the complexity of a species’
behavioural ecology within the framework of resource dispersion. Whatever
larger theoretical framework may emerge to explain lion society,
incorporating fission-fusion dynamics should allow the RDH to be refined
and improved.