Data from: Density-dependent feedback across nested levels of organization in a social primate

The strength and direction of density-dependent mechanisms acting on
individual reproduction and survival may vary across the nested levels of
organization social animals live in, such that complex patterns of density
dependence shape fitness and population growth. Yet knowledge of such
processes of population regulation where individuals are simultaneously
subjected to contrasting density effects remains limited. We quantify and
contrast density effects on components of individual fitness across two
nested levels of organization: the population and the social group, using
45 years of demographic data of rhesus macaques. Our analysis reveals
opposing density feedback on individual reproduction and survival across
levels of organization and shows that density does not affect all life
stages equally. While increased population density reduced female
reproduction during maturation, females in larger groups were more likely
to reproduce. Infant survival was optimal at intermediate population
densities, and monkeys in larger groups showed increased
survival. Our work shows that population-level density effects on
individual reproduction and survival can be as strong as group-level
effects and suggests different roles of the philopatric (i.e. females) and
dispersing (i.e. males) sexes on the regulation of individual demographic
performance. In this way, our work posits testable mechanistic hypotheses
for evaluating density effects on components of individual fitness and
highlights the need to explicitly consider the organization and
demographic structure of social animals when quantifying individual
performance and population dynamics.