Cumulative Early-Life Adversities Predict Short- and Long-Term Survival in a Critically Endangered Lemur (Propithecus...

Adversities in early life compromise fitness components later in life, but the cumulative effects of multiple adversities and their timing across the lifespan remain poorly understood. To contribute comparative data from an independent primate radiation, we leverage long-term demographic data from a wild lemur population to examine the effects of maternal loss, presence of an older sibling, maternal age, group size, temperature and rainfall on survival of 242 infants across the lifespan. We found that differently operationalized cumulative indices of early adversities predicted infant survival but did not predict survival better than single predictor models. Infant survival was reduced by maternal loss, the absence of an older sibling and large group size at death. Survival to adulthood and female longevity were positively associated with higher rainfall during infancy and negatively by larger group sizes at death; infant survival to adulthood also declined with increasing maternal age. Cumulative adversities early in life had no persistent negative long-term effects on survival, but sample sizes decreased in the older age classes. However, rainfall as a proxy for food availability in early life had long-term effects, with higher rainfall increasing the odds of survival to adulthood and female longevity. Hence, social and demographic adversities had stronger effects than environmental ones for early infant survival, but environmental effects in early life also appear to be important drivers of demography and life history in these critically endangered primates.