Individual-level movement bias leads to the formation of higher-order social structure in a mobile group of baboons.

In mobile social groups, influence patterns driving group movement can vary between democratic and despotic. The arrival at any single pattern of influence is thought to be underpinned by both environmental factors and group composition. To identify the specific patterns of influence driving travel decision-making in a chacma baboon troop, we used spatially explicit data to extract patterns of individual movement bias.

Fertility, parental investment, and the early adoption of modern contraception in rural Ethiopia.

Objectives: What triggers initial shifts to fertility limitation as populations undergo socioeconomic development remains poorly understood. Alternative models emphasize the social contagion of low fertility ideals, or the individual perception of economic and/or fitness benefits to fertility limitation. Few micro-level studies in communities experiencing the earliest stages of the demographic transition are available.

Association between hybrid status and reproductive success of captive male and female rhesus macaques (Macaca mulatta) at the California National Primate Research Center (CNPRC).

The California National Primate Research Center (CNPRC) houses more than 1,000 rhesus macaques (Macaca mulatta) of mixed Chinese-Indian ancestry. Most of these animals are kept in outdoor field cages, the colony's long term breeding resource. Since 2001, hybrids comprised between 4 and 49% of the field cage populations, but in most cases have represented a maximum of 10% of those populations.

What role do olfactory cues play in chacma baboon mating?

The probability of ovulation in a number of primate species is associated with both visual and auditory cues. We use 18-month behavioral data from two chacma baboon troops to provide the first systematic assessment of the possibility that olfactory cues are also involved. Using variance in the rate of olfactory inspection by males as a proxy for changes in the intensity of female vaginal odor, we found that rates of inspection were broadly correlated with changes in female fertility.