A group of apes is traditionally called a “shrewdness,” a collective noun that dates back centuries in the English language. In practice, though, primatologists and wildlife writers just as often use “troop,” “band,” or “group,” and the word that fits best depends on which ape you are talking about. The collective noun is a fun piece of trivia, but the real story behind ape grouping is more varied and stranger than a single label can capture.
Where “Shrewdness” Comes From
English has a long tradition of assigning fanciful collective nouns to animals. A murder of crows, a parliament of owls, a shrewdness of apes. Most of these terms trace to the fifteenth-century “Book of Saint Albans,” a compendium of hunting and heraldry terminology published in 1486. The word “shrewdness” reflected the era’s perception of apes as cunning, almost dangerously clever creatures. It stuck in dictionaries and trivia books even though almost nobody working with apes in the field uses it today.
“Troop” is probably the most common word you will encounter in wildlife documentaries and zoo signage. It applies well enough to gorillas, who live in cohesive groups with a clear leader, but it fits awkwardly when describing chimpanzees, whose social units are fluid and constantly reshuffling, or orangutans, who spend most of their lives alone. Researchers tend to use species-specific terminology: a gorilla “group,” a chimpanzee “community,” a gibbon “family group.” If you just want a word for a gathering of apes at trivia night, “shrewdness” is the classic answer. If you want to understand how apes actually live together, you need to look species by species.
Gorilla Groups and the Silverback’s Role
Gorillas are the ape species whose social structure most closely matches what people imagine when they hear the word “troop.” A typical gorilla group contains one dominant adult male, called a silverback for the distinctive patch of silver-gray hair on his back, along with several adult females and their offspring. Group sizes range from about five to thirty individuals, with most groups on the smaller end.
The silverback is not just the biggest animal in the group. He serves as its social anchor. Research on mountain gorillas has found that young gorillas spend the most time near the alpha silverback and interact with him most frequently, particularly during the stage when infants are becoming more independent from their mothers but are still vulnerable.1PubMed. Male-immature relationships in multi-male groups of mountain gorillas (Gorilla beringei beringei) When a silverback dies, the consequences for the group are dramatic. A study at Zoo Atlanta documented a significant spike in aggressive display behaviors among the remaining group members in the three months following the death of their silverback, alongside a noticeable intensification of mother-offspring bonds.2International Zoo Yearbook. Behavioural response of a Western lowland gorilla Gorilla gorilla gorilla group to the loss of the silverback male at Zoo Atlanta Without the stabilizing presence of that one individual, the social fabric frays quickly.
Some mountain gorilla groups include more than one silverback, usually related males such as a father and his adult sons. In these multi-male groups, the alpha silverback still tends to attract the most attention from immatures, but the social dynamics get more complicated. Close to half of female mountain gorillas leave their birth group before they reach breeding age, and about half of males disperse before they become dominant, creating groups with surprisingly high levels of kinship among the remaining members.3PubMed Central. Multiple mechanisms for inbreeding avoidance used simultaneously in a wild ape
Chimpanzee and Bonobo Communities
Chimpanzees and bonobos, our two closest living relatives, live in something called a fission-fusion social system. Members belong to a larger community that can number anywhere from about 20 to more than 150 individuals, but they do not all travel together. Instead, they form temporary parties that change in size and composition over the course of hours or days.4PubMed Central. Ecology rather than psychology explains co-occurrence of predation and border patrols in male chimpanzees You might see a party of four males patrolling the territory boundary in the morning and a mixed group of fifteen sharing a fruiting tree in the afternoon. The community itself is the stable social unit, but the “group” you would observe at any given moment is always shifting.
Within these communities, social relationships are not random. A study of male chimpanzees in Uganda’s Budongo Forest found that the males in one community organized into a core-periphery network, where core individuals were most likely to be connected to one another, and connections between core and peripheral males were more common than connections among peripheral males alone.5PubMed Central. Flexibility in the social structure of male chimpanzees (Pan troglodytes schweinfurthii) in the Budongo Forest, Uganda The composition of the core shifted from year to year, so the structure is real but flexible rather than locked in place.
Bonobos, sometimes called pygmy chimpanzees, use a broadly similar fission-fusion system but with important social differences. Female bonobos hold more social power than female chimpanzees do. Observations at the Lola ya Bonobo Sanctuary found that adult male bonobos are rarely aggressive toward offspring whose mothers are present, and some juveniles raised by their mothers achieve social rank higher than adult males.6Bonobos. Bonobo baby dominance: Did female defense of offspring lead to reduced male aggression? The “group” in bonobo society is not just a collection of individuals; it is a web of maternal alliances and cross-sex relationships that looks quite different from the male-dominated coalitions of chimpanzees.
Orangutans and the Limits of “Group”
Orangutans are the outlier among the great apes. They are often described as semi-solitary, and for good reason: an adult male orangutan typically travels alone, and adult females spend most of their time with only their dependent offspring for company. If you are looking for a “group” of orangutans in the traditional sense, you will mostly be disappointed.
But calling orangutans solitary oversimplifies things. Female orangutans form loose clusters of relatives with highly overlapping home ranges and show preferential association with one another. Neighboring mothers with similarly aged offspring have been found to show disproportionately high annual overlap in their space use, regardless of how closely related they are or how much fruit is available. Rather than shifting or expanding their ranges, these mothers intensify their use of shared areas within existing boundaries, a strategy that appears to give their offspring opportunities for social play.7PubMed. Sex-biased dispersal and volcanic activities shaped phylogeographic patterns of extant Orangutans (genus: Pongo) So while you would rarely see a “troop” of orangutans, there is a social network operating beneath the surface, expressed through overlapping territories and deliberate proximity rather than constant togetherness.
Genetic studies confirm that male orangutans disperse much farther than females. Deep geographic structure is visible in maternal DNA lineages but not in the male population history, pointing strongly to male-biased dispersal.7PubMed. Sex-biased dispersal and volcanic activities shaped phylogeographic patterns of extant Orangutans (genus: Pongo) Females tend to settle near where they grew up, forming those kin-based clusters, while males roam widely. The result is a social system that looks solitary on the surface but has a quiet structure underneath.
Gibbons and the Family Unit
Gibbons and siamangs, collectively known as the lesser apes, were long considered the textbook example of primate monogamy. The standard picture was a mated pair living together on a defended territory with their offspring, singing elaborate duets at dawn. This description is not wrong exactly, but it turns out to be incomplete.
Long-term field studies have shown that pair-bonding and two-adult groups are not universal among gibbons. Some populations include groups with extra adults, and the social organization is better described as variable communities that arose from ecological pressures rather than a strict monogamous mating system.8PubMed. Hylobatid communities: Changing views on pair bonding and social organization in hominoids The pair bond itself also varies in strength across species. A comparative study found that siamangs appear to have a stronger pair bond than pileated gibbons, based on the physical distance partners maintain from each other. Interestingly, siamang males invest more into maintaining the pair bond through grooming than females do, while the opposite pattern holds in crested gibbons and pileated gibbons.9IntechOpen. Taxon-Specific Pair Bonding in Gibbons (Hylobatidae)
So a “group” of gibbons is typically small, just two to six individuals in a family unit, but the internal dynamics of that tiny group are more nuanced than they first appear. The collective noun “shrewdness” feels particularly ill-fitting here, since you would almost never see gibbons in a large gathering.
What Holds an Ape Group Together
Across all the ape species that do form groups, the social glue is remarkably consistent: physical contact, especially grooming. Grooming is not just about hygiene. In primates, it triggers endorphin release, creating a neurochemical reward that reinforces social bonds. These bonded relationships form the foundation for coalitions and alliances within groups.10PubMed Central. Bridging the bonding gap: the transition from primates to humans
Experimental work with both chimpanzees and bonobos has confirmed that grooming and play function as a kind of social currency that can rapidly reshape relationships, especially between individuals who do not know each other well.11Behaviour. Experimental evidence that grooming and play are social currency in bonobos and chimpanzees A newcomer to a group who grooms the right individuals can build alliances faster than one who does not. This helps explain why ape groups, despite their frequent internal tensions, manage to hold together at all. The endorphin hit from being groomed is a small but powerful incentive to tolerate your neighbors.
For orangutans, which lack the constant proximity of group living, these bonding mechanisms still operate but on a slower, sparser schedule. When orangutan mothers do encounter each other, their offspring play together, and the social interactions that occur during those meetings may be compressed versions of what happens continuously in a chimpanzee community.
Who Leaves and Who Stays
One of the less obvious things that shapes ape group composition is dispersal: which sex leaves the birth group and which stays. The pattern differs across species and has major consequences for how related the members of any given group turn out to be.
In chimpanzees, females typically leave their birth community at adolescence and transfer into a neighboring one, while males stay put. This means male chimpanzees within a community are often related, which helps explain their willingness to cooperate in territorial defense and hunting. Bonobos follow a similar pattern of female dispersal, though the dynamics after transfer are different because immigrant females can build strong bonds quickly, partly through sexual behavior that is far more frequent and varied than in chimpanzees.
Gorillas show a more complex picture. In western gorillas, genetic analysis has revealed that males disperse farther than females, and adult females within groups are not significantly more related to each other than females across groups.12PubMed Central. No evidence for female kin association, indications for extragroup paternity, and sex-biased dispersal patterns in wild western gorillas This was a surprise, since earlier assumptions held that female gorillas would cluster with relatives. In mountain gorillas, both sexes show flexible dispersal, with roughly half of each sex leaving their natal group before reaching breeding or dominance age, leading to high levels of kinship within multi-male groups and a real risk of inbreeding that the gorillas navigate through multiple avoidance strategies.3PubMed Central. Multiple mechanisms for inbreeding avoidance used simultaneously in a wild ape
For orangutans, the pattern is male-biased dispersal, with females tending to settle near their birthplace and males ranging widely.7PubMed. Sex-biased dispersal and volcanic activities shaped phylogeographic patterns of extant Orangutans (genus: Pongo) This contributes directly to the loose female clusters described earlier. Gibbons follow yet another pattern: offspring of both sexes eventually leave the family territory to find a mate and establish their own territory, which is part of why gibbon groups stay small.
Captive Ape Groups Are Not the Same
If your main experience with ape groups is watching them at a zoo, the dynamics you see are shaped by constraints that do not exist in the wild. Captive chimpanzees, for instance, do not face food scarcity, competition from neighboring communities, or predation. Without those pressures, their social behavior can look quite different. Zoo managers also have to balance the desire for large, naturalistic multi-male groups against practical limits on space per animal and the risk of aggression that comes with forced proximity.13American Journal of Primatology. Does group size matter? Captive chimpanzee (Pan troglodytes) behavior as a function of group size and composition A “troop” of chimpanzees at a zoo is a curated social arrangement, not a naturally formed community.
Gorilla groups in captivity face similar challenges. When zoos lose a silverback, they must decide quickly how to manage the resulting social disruption, since the behavioral fallout can be swift and intense. Some facilities introduce a new male, while others allow a female-led group to persist temporarily. These management decisions have no parallel in the wild, where groups that lose their silverback typically dissolve, with females transferring to other males.
The Evolutionary Roots of Ape Grouping
Given the range of social systems across living apes, researchers have long debated what the ancestral condition looked like. A phylogenetic analysis using data from hundreds of primate populations estimated that the ancestor of all primates lived in a variable social system, with pair-living as the most common arrangement but with roughly 10 to 20 percent of social units deviating from that pattern by being solitary.14PubMed Central. Primate social organization evolved from a flexible pair-living ancestor Body size and whether a species is active during the day or night had large effects on which social organization evolved. In other words, the diversity of ape grouping patterns we see today, from solitary orangutans to fission-fusion chimpanzee communities, likely radiated from a flexible starting point rather than from a single rigid template.
Even the fossil record offers tantalizing hints. A set of Early Pleistocene hominin trackways from northern Kenya preserves footprints indicating larger-than-average body sizes. Researchers have interpreted these tracks as evidence that the group included multiple adult males, providing rare direct evidence for social behavior in ancient human relatives.15Proceedings of the National Academy of Sciences. Insights into hominin body size, locomotion, and behavior from Early Pleistocene trackways in northern Kenya Fossil footprints cannot tell us what those ancient hominins called their group, of course, but they confirm that traveling in multi-individual parties has deep roots in the ape lineage.
Why One Word Will Never Be Enough
The question “what is a group of apes called?” has a tidy answer for trivia purposes: a shrewdness. But the tidiness is misleading. A gorilla troop led by a silverback, a chimpanzee community whose members fission and fuse throughout the day, a pair of gibbons singing on their territory, and a lone female orangutan whose home range quietly overlaps with her sister’s are all “groups of apes” in some sense, yet they share almost nothing in terms of structure, size, stability, or internal politics. The English language gives us one collective noun; the apes themselves give us at least half a dozen fundamentally different ways of being social. That mismatch is worth remembering the next time the question comes up at a dinner party.