Effect of Social Dominance and Reproductive State on Adrenal Steroids in Female Japanese Macaques (Macaca fuscata)

The relationship between stress and behavior can help us to understand how physiological adaptations shape primate societies. Most studies have focused on glucocorticoids (GC) as stress biomarkers, but other extrinsic and intrinsic factors can influence GC levels and confound the results. To overcome this issue, including analyses of dehydroepiandrosterone-sulfate (DHEAS), a GC antagonist, can be […]

Evaluating mood changes in response to anthropogenic noise with a response-slowing task in three species of zoo-housed primates

In the zoo environment, anthropogenic noise is common as sound levels fluctuate due to visitors, construction, habitat design, and special events. In this study, changes in the mood of three species of zoo-housed primates in response to a loud annual event were evaluated with the response-slowing paradigm. In this paradigm, animals experiencing anxiety slow responses […]

Environmental and Social Factors Associated with the Occurrence of Stone-Handling Behavior in a Captive Troop of Macaca fuscata

Stone-handling, a documented behavioral tradition in Japanese macaques (Macaca fuscata), occurs in both captive and provisioned free-ranging troops. We utilize data systematically collected as part of a broader investigation of stonehandling behavior in a captive troop to elucidate the environmental and social factors responsible for its occurrence. We analyzed contexts of stone-handling over 18 mo […]

Physical intuitions about support relations in monkeys (Macaca fuscata) and apes (Pan troglodytes)

Nonhuman primates, like humans, have demonstrated various physical intuitions. Cacchione and Krist (2004) examined chimpanzees’ intuitions about support relations with the violation-of-expectation task. They reported that the chimpanzees possessed intuitions about support, but their intuitions differed from those of humans in part; they were sensitive to “contact/no-contact” and “amount of contact” but not “type of […]

Grooming and coalitions in Japanese macaques (Macaca fuscata): Partner choice and the time frame reciprocation

Evidence of a reciprocal exchange of grooming and agonistic support in primates is mixed. In this study, the authors analyzed a large database of grooming and coalitions in captive female Japanese macaques (Macaca fuscata) to investigate their within-group distribution and temporal relations. Macaques groomed preferentially those individuals that groomed them most and supported preferentially those […]

Relationship with the mother modulates the response of yearling Japanese macaques (Macaca fuscata) to the birth of a sibling

The authors investigated the changes induced by the birth of a sibling in the relationship of 1-year-old Japanese macaques (Macaca fuscata) with their mothers and group companions. After the birth of a sibling, mother-yearling contact, proximity, and grooming decreased dramatically. Yearlings responded to such a reduction in maternal care in either of 2 radically different […]

Enclosure environment affects the activity budgets of captive Japanese macaques (Macaca fuscata)

Individuals adapt to changes in their environment, such as food availability and temperature, by adjusting the amount of time spent in different behavioral activities. These adjustments in behavior should vary across age–sex class according to specific physiological and social needs. We studied the activity budgets of three social Japanese macaque groups inhabiting either vegetated or […]

Social tolerance and adult play in macaque societies: a comparison with different human cultures

Differences in play behaviour often illuminate complex ecological parameters and social differences. In primate societies, including humans, individuals acquire information through play. It is adults in every community that are most committed to managing social practices. In tolerant species, adults often participate in play to reinforce social networks and cooperation. The 20 macaque species are […]

Influence of Heavy Snow on the Feeding Behavior of Japanese Macaques (Macaca Fuscata) in Northern Japan

Natural disasters can degrade primate habitat and alter feeding behavior. Here, we examined the influence of unusually heavy snow on diet and feeding-site use by Japanese macaques (Macaca fuscata) in northern Japan. To compare the winter-feeding behavior under different snow conditions, we recorded the plant species foraged on by macaques in multiple transects of the […]

Environmental, biological, and social factors influencing fecal adrenal steroid concentrations in female Japanese macaques (Macaca fuscata)

The ability to determine hormonal profiles of primate populations using non-invasive techniques can help to monitor physical fitness, stress, and physiological responses to environmental changes. We investigated fecal glucocorticoids (fGC) and DHEAS concentrations in captive Japanese macaques (Macaca fuscata) in relation to environmental, biological, and social factors. The subjects were female Japanese monkeys from 4 […]