Primate Behavior and Ecology

Activity Budgets and Boldness as Potential Predictors of Release Readiness in Rehabilitating Javan Slow Lorises

The paper assesses activity budgets and boldness in Javan slow lorises to evaluate their readiness for release from rehabilitation.

Vocal coordination and conflict avoidance shape fission-fusion dynamics in white-nosed coatis

This study identifies vocal coordination and conflict avoidance as drivers of fission-fusion dynamics in white-nosed coatis by analyzing subgrouping events and vocalizations.

Play vocalizations induce affective bias in reward learning and memory in orangutans

This study shows that orangutans exhibit affective biases in reward learning and memory when exposed to conspecific play vocalizations.

The evolution of non-seasonal breeding in primates

This study examines factors influencing reproductive seasonality in primates, finding that productivity and behavioral strategies affect seasonality more than environmental constraints.

Spontaneous rhythmic and tool-assisted drumming across variable tempo and technique in a captive chimpanzee

This study documents a captive chimpanzee's ability to produce flexible rhythmic drumming across different tempos and techniques, showing similarities to human musicality.

Environmental fluctuations alter the competitive trade-offs of group size in a social primate

The paper shows how environmental changes affect competition between and within groups of capuchin monkeys, altering their space use and foraging strategies.

A cross-center comparison of the relationship between matriline fragmentation, grooming cohesion, and agonistic behavior in captive rhesus macaque (Macaca mulatta) social groups

Across 105 rhesus macaque matrilines at two primate centers, family grooming cohesion drops below a mean kinship threshold of 0.16, while lower kinship continuously increases severe within-family aggression.

Disparate social structures are underpinned by distinct social rules across a primate radiation

The paper quantifies variation in primate social structures across 11 species, identifying distinct patterns in kin and rank biases and male-centered subgrouping.

No evidence of reactive avoidance of baboons (Papio ursinus and Papio anubis) to the presence of predators

This study examines whether baboons avoid areas after predator encounters and finds no evidence of reactive avoidance.

Chimpanzee culture beyond the conspicuous: Evidence for broad-scale observational social learning in wild individuals

This study investigates peering behavior in wild chimpanzees to assess social learning and cultural transmission of everyday skills, finding that peering is used for targeted information seeking and may function as a signal for social interaction.

Complex modulation of visual attention to 3rd person interactions in wild macaques

The paper examines how social factors influence visual attention in wild macaques during third-person social interactions.

Monkeys integrate facial expressions and direct gaze to modulate gaze-following behavior

This study shows that rhesus macaques use direct gaze combined with threat expressions to speed up gaze-following, while submissive expressions delay it when gaze is averted.

The Balancing Act: Olive baboon (Papio anubis) occupancy is associated with resource-related environmental variables rather than relative abundance of predators.

This study examines how environmental resources influence olive baboon occupancy in the Serengeti, finding that resource availability outweighs predator presence in habitat selection.

Context-Dependent Reactive Antipredator Behavior of Chacma Baboons (Papio ursinus) Amidst Predator Recovery

This study examines how chacma baboons adjust their antipredator behaviors in response to changes in predator density and species, finding context-dependent flight and vigilance responses.

Distribution of genetic paternity in primate groups

The paper compiles genetic paternity data from 52 primate species and uses Bayesian regression to analyze how phylogeny, group composition, and seasonality influence paternity shares among primary males.

Which senses do wild vervet monkeys (Chlorocebus pygerythrus) use for evaluating potential food items?

This study examines which senses vervet monkeys use to evaluate food, finding vision is most commonly used, with variations by food type and sex, and low rejection rates suggest food familiarity.

FIRST EVIDENCE OF OBJECT PLAY IN WILD GELADAS: FUNCTIONAL IMPLICATIONS FOR LATER UTILITY AND RE-ELABORATED OBJECT USE IN ADULTHOOD

The paper reports the first evidence of object play in wild geladas, suggesting it may be a biologically rooted behavior influenced by ecological factors.

Rhesus monkeys use both eye and head gaze to reallocate covert spatial attention facilitating visual perception

This study shows rhesus monkeys can use eye gaze to direct attention, but only when gaze is combined with head movement or when the stimulus is close, suggesting eye gaze is not uniquely human.

Parental rejection is associated with extended lifespan in owl monkeys in captivity

This study finds that parental rejection in owl monkeys is linked to longer lifespans in both parents and their offspring in captivity.

Wild chimpanzees in Bugoma Forest, Uganda follow the Ugandan feeding ecology etiquette but exhibit cultural singularities: a case for the cultural junction hypothesis

This study describes the feeding ecology of wild chimpanzees in Bugoma Forest, Uganda, and suggests they occupy a cultural junction, influencing regional behavioral diversity.

Social tolerance mediates social learning in wild red-fronted lemurs (Eulemur rufifrons) and ring-tailed lemurs (Lemur catta)

This study shows that social tolerance in red-fronted lemurs facilitates faster and more widespread social learning compared to less tolerant ring-tailed lemurs.

Toward neuroanatomical and cognitive foundations of macaque social tolerance grades

The paper examines the relationship between amygdala volume and social tolerance in macaques, finding that tolerant species have smaller amygdala volumes that decrease with age, while intolerant species show increasing amygdala volumes.

Demographic, behavioral, and ecological data from a long-term field study of wild baboons in Amboseli, Kenya

The paper provides four newly available data sets from a long-term study of wild baboons in Amboseli, Kenya, covering demographics, activity, diet, and weather data spanning 1971-2023.

Making friends in an asymmetric game: the establishment of male-female grooming exchanges in vervet monkeys

The study examines grooming exchanges between male-female vervet monkeys, finding that females initially invest heavily and reduce grooming over time, while males increase frequency after residency, leading to near reciprocity.

Mothers letting go: postnatal maternal investment shapes sex-specific social development in wild vervet monkeys

The paper examines how postnatal maternal investment shapes sex-specific social development in wild vervet monkeys, finding that maternal age and rank influence offspring sex ratios, survival, and social integration differently in sons and daughters.

Ecological Factors Affecting Prosociality in Marmoset Monkeys

This study examines how ecological factors like food size and time since food access affect prosocial behavior in marmosets, finding that larger food portions promote sharing but this effect diminishes with increased hunger.

Otters, but not apes, prepare for mutually exclusive possibilities.

This study shows otters outperform chimpanzees in a task requiring preparation for mutually exclusive outcomes, suggesting adaptive cognition shaped by ecological demands rather than social complexity.

Sex-specific effects of social bonds on glucocorticoids in wild chimpanzees

The paper examines sex-specific effects of social bonds on glucocorticoid levels in wild chimpanzees, finding stronger bonds correlate with lower cortisol in females and higher cortisol in males.

Effects of age and sex on diet and activities of immature reintroduced western lowland gorillas.

This study examines the diet and behavior of immature reintroduced western lowland gorillas, finding no significant age or sex differences in behavior or diet.

Infant corpse carrying in Pan reflects maternal attachment and death context

The paper analyzes infant corpse carrying in Pan to show it is influenced by maternal behavior, death context, and life history, suggesting cognitive frameworks for death recognition evolved after the Pan-Homo split.