23.2 Animal Societies
Key Takeaways
Group living can provide more eyes for predators and cooperative hunting or defense, at the cost of competition, disease, and conspicuousness.
A honeybee colony has a queen, workers who are usually her daughters, and drones, which are males; workers perform the waggle dance.
The waggle dance communicates direction relative to the sun and a code for distance.
Bird societies use song, territorial display, and biparental care; social monogamy is more common in birds than in mammals because the young often need two parents.
Primate troops use grooming, dominance hierarchies, and alliances, with long juvenile periods of learned social behavior; a hierarchy is not a fixed action pattern.
23.2 Animal Societies
A society is a group whose members communicate and hold different roles. The societies here are honeybee colonies, bird breeding groups, and primate troops.
Costs and benefits
More eyes for predators means that some animals can feed while others watch. A goose at the edge of a flock, or a monkey that gives an alarm call, can warn the rest. One animal's chance of being taken can also fall when a predator removes a single prey from a large group. Cooperative hunting lets wolves and lions take prey that one hunter cannot hold. Cooperative defense works the other way: small birds mob an owl, and honeybees meet an intruder at the nest entrance. An animal that has already found food can also signal the others.
Competition rises because neighbors want the same food, mates, and shelter. Disease and parasites spread when animals touch, share food, or sleep in one nest. Conspicuousness means a moving flock or a troop in the open is easier for a predator to notice than a solitary animal in cover. Group life is favored when vigilance, hunting, or defense outweighs those costs.
Honeybee society
A honeybee colony divides labor among three castes. The queen is the reproductive female. She lays the eggs and releases chemical signals that keep workers gathered on colony tasks. Workers are females, and they are usually daughters of the queen. They clean cells, nurse brood, build comb, guard the entrance, and forage. A worker's jobs often shift with age, from indoor tasks toward foraging. Drones are males. They develop from unfertilized eggs and leave the hive to mate. A drone is not the worker who dances.
The waggle dance
Foragers report a rich patch with the waggle dance. On the vertical comb, the dancer uses straight up in place of the sun's position. The angle between the waggle run and vertical matches the direction of the food relative to the sun. The duration of the waggle run is a code for distance: a longer waggle stands for a farther source. Nestmates follow the dancer and leave with both pieces of information. When food is nearby, a round dance arouses foragers without that solar direction. The dancer is a worker.
Division of labor assigns egg laying to the queen, nest work and dancing to the workers, and mating flights to the drones. Kin selection, already introduced in evolutionary ecology, applies in one step. Workers are usually the queen's daughters, so rearing her young can spread shared genes even though those workers rarely found nests of their own.
Bird societies
Bird societies are often built on a breeding territory. Song advertises who holds a space and can attract a mate. Territorial display adds postures and chases that defend the nest area. Many chicks hatch helpless and need a steady food supply. Biparental care, feeding by both parents, is common for that reason. Social monogamy, a breeding bond between one female and one male at a nest, is more common in birds than in mammals because the young often need two parents.
Cooperative breeding goes further in some species. Helpers at the nest, such as young Florida scrub-jays that stay and feed their parents' next brood, are often relatives of the chicks they aid. That help can be tied to kin selection: the helper raises the survival of kin when its own chance to breed that season is small. Many songbirds also memorize an adult song during a sensitive period, so bird society can mix a territorial pattern with a learned vocal signal.
Primate societies
Primate troops emphasize relationships learned over a long life. In baboons or macaques, grooming removes parasites and also maintains bonds. Animals groom allies more than strangers. A dominance hierarchy ranks members so higher-ranking animals have priority at food, resting places, and mates. Rank is shown by threats, submissive postures, and who gives way. Once the order is known, many disputes are settled with signals.
Alliances sit inside that rank order. Two animals may support each other against a rival, and relatives often back one another. Chimpanzee males form coalitions that can change who holds high rank. These tactics are learned. Primates have long juvenile periods: infants stay dependent for years, watch grooming and fights, and use play to rehearse adult signals. A dominance hierarchy is a learned rank order. It is not a fixed action pattern released by one sign stimulus and run to completion.
| Feature | Honeybees | Birds | Primates |
|---|---|---|---|
| Reproduction | A queen lays the eggs; workers are usually her daughters | A social pair is typical, and both parents often feed the young | Several adults may breed, and rank affects access to mates |
| Males | Drones are males and do not perform the waggle dance | The male of a pair commonly shares care | Males may hold rank, form alliances, and compete |
| Main signal | Waggle dance: direction relative to the sun and a code for distance | Song and territorial display | Grooming and postures that maintain a hierarchy |
| Kinship and learning | Daughter workers divide labor and rear the queen's brood | Helpers at the nest can raise the survival of kin | Long juvenile periods of learned social behavior |
Warning
A drone is a male honeybee, not the worker who dances. Workers, usually daughters of the queen, perform the waggle dance. A dominance hierarchy is not a fixed action pattern. Rank is a learned order inside a troop, not a stereotyped sequence released by a sign stimulus and run to completion.
How to read a society item
Name the animal, then the role. In a bee colony, separate queen, worker, and drone before you interpret a dance. At a bird nest, look for song, a territory, and care from two parents. A helper can be explained by kin selection as aid to relatives. In a primate troop, look for grooming, rank, and alliances learned during a long juvenile life. More eyes and cooperative hunting or defense are benefits. Competition, disease, and conspicuousness are costs.
A honeybee returns from flowers and performs a waggle dance on the vertical comb. Nestmates then depart toward that patch. What does the dance communicate?
The direction of the food relative to the sun, and a code for distance.
A dominance hierarchy that ranks every bee in the hive.
Only that a drone is ready to mate, with no information about food.
The egg-retrieval sequence of a graylag goose, performed on the comb.
Which statement best states the costs and benefits of living in a group?
The benefits of grouping are limited to primates, while insects and birds receive none.
Group living removes competition and disease, leaving a fixed action pattern as the only remaining issue.
More eyes for predators and cooperative hunting or defense can outweigh competition, disease, and conspicuousness.
Conspicuousness is a benefit, and cooperative defense is a cost paid only by solitary animals.
Which description of roles in these societies is accurate?
Helpers at the nest are unrelated drones, and their dance replaces care by bird parents.
Social monogamy is rarer in birds than in mammals because young birds never need care from two parents.
Drones perform the waggle dance, and a primate dominance hierarchy is a fixed action pattern triggered by one sign stimulus.
Honeybee workers, usually daughters of the queen, dance and forage, while drones are males; a primate dominance hierarchy is a learned rank order.
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