Chapter 35 Behavioral Adaptations to the Environment

Natural Selection

Environmental pressures select for advantageous traits (one important mechanism driving evolution)

Sexual Selection

prospective mates select for advantageous traits (another important mechanism driving evolution)

Phenotype

physical traits (acted on by selection)

Genotype

genetic makeup (code for phenotype/physical traits)

Evolutionary traits

the fittest individuals have the largest number of viable, fertile descendants (thus pass on the greatest number of their alleles)

being able to have viable offspring that can reproduce themselves and pass on adapted traits

Relative fitness

success in contributing to a population’s gene pool relative to the contributions of other individuals

What is behavior in animals?

the sum of an animal’s responses to internal and external environmental cues

What is behavioral ecology?

the study of behavior in an evolutionary context, considering both proximate causes and ultimate causes

How do proximate and ultimate causes of behavior differ?

proximate causes are immediate and ultimate causes are evolutionary

What are two types of selection that contribute to ultimate causes of behavior?

sexual selection and natural selection

Habituation

an animal learns not to respond to a repeated stimulus that is not of critical importance

“tuning something out”

stimulus is still detected but the animal does not respond to it

Imprinting

learning that is irreversible and limited to a sensitive item period in an animal’s life

What is learning in nature?

modification of behavior as a result of specific experiences

Spatial learning

use of landmarks to learn the spatial structure of the environment

Associative learning

Behavioral change based on linking a stimulus or behavior with a reward or punishment; includes trial and error learning

Social learning

learning by observing and mimicking others

Problem solving

inventive behavior that arises in response to a new situation

How does fitness relate to the persistence of adaptive traits/behaviors over time?

adaptive traits/behaviors that enhance fitness are passed on in gene pool

Imprinting

learning that is limited to a specific time period in an animal’s life and that is generally irreversible. vital for infant development (ex. a young bird learning to identify its parents, song development)

Sensitive period

the limited phase in an animal’s development when it can learn certain behaviors

How are whooping cranes an example of imprinting and conservation?

population got down to 22, tried captive breeding.. wanted another species of crane to teach them how to migrate. use a puppet head to teach these birds how to feed and fly with the help of a plane

Altruism / Altruistic behavior

behavior that reduces an individuals fitness while increasing the fitness of others in the population

Inclusive fitness

an individuals success at perpetuating its genes by producing its own offspring and/or helping close relatives, who likely share many of those genes, to produce offspring

Kin selection

natural selection favoring altruistic behavior that benefits relatives

How does taxis differ from kinesis?

a kinesis is a random movement in response to stimulus whereas a taxis is a response directed toward (positive taxis) or away from (negative taxis) a stimulus

What is phototaxis?

taxis towards light (positive) or away from light (negative)

What is chemotaxis?

taxis towards chemicals (positive) or away from chemicals (negative)
salmon have positive chemotaxis towards chemicals

Planarians move directly away from light while seeking dark places. What type of movement is this?

Negative phototaxis

What is spatial learning?

animals establish memories of landmarks in their environment
ex. locations of food, nest sites, prospective mates, and potential hazards

How do digger wasps relate to spatial learning?

the arrangement of landmarks led the digger wasps to the nest, it was the arrangement of landmarks in space and not the type of landmark

What is migration and why does it happen?

directed movement of animals between two geographic areas (usually seasonal)
places are optimal for finding food in one place over another

What type of cue features prominently in ocean migrations of sea turtles and salmon?

magnetic cues feature prominently in sea turtle migration, some organisms have magnetic type crystals in their tissue to direct movement

landmarks in the ocean when looking above the water

Semelparous

pacific salmon (5 species) all die after spawning once

Iteroparous

Atlantic salmon (1 species) may spawn multiple times

How does salmon navigation/migration work? How does imprinting assist this process?

Imprinting: odors of natal stream/river

Spatial learning: navigation through rivers

Magnetic cues: help navigate through ocean to find locations on coastline (river entrance)

once they are in freshwater they use visual learning and smell to get back to where they need to spawn

use vision and smell to find spawning ground (place of birth)

What animal makes the longest migration?

Arctic tern.. pole to pole then all the way back

can sleep while gliding, 1k miles day

How does the generational timing of monarch migration work? What plant supports monarch eggs and caterpillars?

they complete a multi-generational migration, travel up to 3000 miles to overwinter in California and Mexico

Migration is carried out by multiple generations, no single organism completes the full migration

one generation flies south, overwinters, and reproduces early in northward migration

subsequent generations needed to finish northward migration and complete summer growing season

planting milkweeds supports monarch reproduction

How might the fact that many bad-tasting, toxic, or stinging species have conspicuous color patterns benefit both those individuals and the animals that may prey on them? What is the term for this coloration? How does (Bayesian) mimicry take advantage of this?

associative learning is the ability to associate an environmental feature with an outcome, the conspicuous color patterns on bad tasting, toxic or stunning species is aposematic coloration, this benefits the bright colored animals because they don’t get messed with and benefits predators so they don’t eat poisonous animals

Bayesian mimicry takes advantage this by resembling an animal that is typically avoided by predators.

What is social learning?

learning by observing the behavior of others

(ex. vervet monkey infants give calls and adults will only repeat it if they have identified the correct threat)

What is cognition?

the process of perceiving, storing, integrating and using information

What is a search image, and what is its purpose?

a mental picture of the desired food enables an animal to forage efficiently

What does the optimal foraging model predict?

How do wagtails exemplify this in nature?

predicts that feeding behavior will maximize energy gain and minimize energy expenditure and risk

eating the intermediate size of the bug, less energy exertion, smaller flies are easy but less nutrition provided, big lies require too much energy

Social behavior

interactions between two or more animals

Signal

stimulus transmitted by one animal to another

communication

includes sending, receiving, and responding to signals

What type of communications are used for different animals (nocturnal, diurnal)

nocturnal mammals use odor and sound

diurnal birds use visual and auditory signals

fish use visual signals, electrical signals and sound

What is the purpose of the honeybee waggle dance?

signal the location of food source to other bees

What are the 3 critical components of the honeybee waggle dance?

repetition of dance - more exciting food source

direction of waggle - direction of food source

duration of waggle - how far away

How is social learning involved with the honeybee waggle dance?

interested in other foragers, learn waggle dance from older bees before trying to do it themselves, young bees learn from old bees

How are imprinting/sensitive period involved in the honeybee waggle dance?

space inside the brain that is open for that period of time to learn it, learning the waggle dance from elders is critical

need to learn all 3 components from an older bee, if they didn’t have a teacher they would dance too long and it would not fix over their lifetime

How does the red-capped manakin courtship ritual exhibit a dominant hierarchy?

courtship ritual - the ritual confirms that individuals are of the same species, of the opposite sex, physically primed for mating, and not threats to each other

physical characteristics are linked to quality

What is a territory?

an area that one or more individuals defend and from which other members of the same species are usually excluded

What are the benefits of defending a territory?

territories protect access to feeding, mating, rearing young, or a combination of these activities

familiarity with a specific territorial area may help avoid predation; forage more efficiently

benefits outweigh energy costs of defending territory

What is agnostic behavior?

threats, rituals, and sometimes combat that determines which competitor gains access to a resource

usually shows of strength, as violent combat can reduce fitness for both parties

Why are ritualistic shows of strength more commonly selected for than violence?

dominance hierarchy allows individuals to rank themselves from most to least dominant based on social interactions, dominant males monopolize fertile females