Behavior & Ecology: Nervous System, Learning, Social Structures, and Migration

biological definition of behavior

Coordinated response of an organism to internal/external stimuli, including feeding, reproduction, locomotion, predator avoidance, communication.

not deterministic behavior

The same stimulus can lead to different responses depending on experience, energy reserves, and context.

Broca's area

Brain region that controls speech in humans; damage impairs speech production but not comprehension.

PET/MRI studies on behavior

Distinct brain regions activate during specific tasks, showing neural basis of behavior.

Fixed Action Pattern (FAP)

An innate, stereotyped behavioral sequence triggered by a specific stimulus, performed the same way each time.

examples of FAPs

Gull chicks pecking red spot → feeding; Greylag goose egg retrieval; Spider web construction.

learning in behavioral biology

A long-term change in behavior resulting from experience.

imprinting

Irreversible learning during a critical period (e.g., Lorenz's goslings imprint on him).

Darwin's finches song learning timing

Must hear their father's song between 10-40 days old, critical for mate attraction.

finch song learning and species boundaries

Prevents cross-mating; maintains reproductive isolation.

indigo buntings orientation learning

Learn orientation for migration by learning the North Star as a stationary point relative to rotating night sky.

experiment confirming buntings' star learning

Planetarium trials showing they orient by whichever star appears stationary.

maternal licking effects on rat offspring

High licking → calm, exploratory, reduced stress hormones. Low licking → anxious, high corticosterone.

phenotypic plasticity

The ability of one genotype to produce different behaviors depending on environment; locust solitary vs. swarming phases.

trigger for locust swarming behavior

Crowding → increased serotonin → gregarious phase.

frog vs. toad escape physiology

Frogs use anaerobic metabolism → short, fast bursts, fatigue quickly. Toads use aerobic metabolism → slower, longer endurance.

male elk antler growth

To compete for mates during rutting season.

young hyenas jaw/muscle development

Needed before effective feeding to compete in dominance-based access to carcasses.

physical trait influencing sound frequency in animals

Body size; larger = lower/deeper calls.

honest signals in animal calls

They're constrained by physical traits (e.g., body size), making them reliable indicators of fitness.

difference between orientation vs. navigation

Orientation is the ability to determine one's position relative to the environment, while navigation involves planning a route to a specific destination.

Orientation

positioning relative to cues

Navigation

finding a path to a specific destination

Path integration

dead reckoning: step counting + direction memory

Sun compass in pigeons

A functional circadian clock to adjust for sun movement

Polarized light in orientation

Insects detect skylight polarization, useful even in cloudy conditions

Species using Earth's magnetic field

Sea turtles, pigeons, fish

Night-migrating birds orientation

Constellations (star compass)

Honeybee waggle dance communication

Direction (angle relative to sun) and distance (duration of waggle run) to food

Migration example: godwits

Bar-tailed godwits fly 10,000 km nonstop Alaska → New Zealand

Migration example: sea turtles

Loggerhead turtles navigate a multi-year Atlantic circuit guided by magnetic fields

Society in animals

A group of individuals living and interacting in an organized, coordinated manner

Benefits of social living

Predator detection, dilution of predation risk, cooperative foraging, thermoregulation

Costs of social living

Competition, parasite/disease spread, higher visibility to predators

Equal-status social structure example

Fish schools, bird flocks (no hierarchy)

Hierarchical social structure example

Impalas (dominant male monopolizes breeding), vervet monkeys (dominance hierarchy)

Hallmarks of eusociality

Division of reproductive labor (queen vs. workers), overlapping generations, cooperative brood care

Animal examples of eusociality

Bees, ants, termites, naked mole rats

Altruism in animal behavior

A costly act that benefits another individual (e.g., ground squirrel alarm calls)

Kin selection explanation of altruism

By helping relatives, an individual increases its inclusive fitness (passing on shared genes)

Behavior maintaining reproductive isolation

Species-specific courtship signals prevent interbreeding (e.g., Darwin's finch songs, mice habitat preferences)

Territory vs. home range

Territory = defended space with exclusive resources. Home range = used area that may overlap with others

Costs and benefits of territoriality

Benefit: exclusive resources, familiarity. Cost: time and energy defending

Optimal foraging theory

Animals maximize net energy gain (benefits - costs)

Example of optimal foraging study

Heinrich's bumblebees: forage on rhododendron (high reward, worth cold cost), avoid cherry blossoms (low reward, not worth cold)

Temporal niche partitioning

Different activity times reduce competition/predation risk

Example of temporal partitioning

Bats feed at night, diurnal insects during day → avoids overlap