ANIMAL BEHAVIORPaige, Emily, and Lily :)

51.1-ethology- the scientific study of how animals behave, particularly in their natural environments -Understanding Behavior requires answering four questions, two about proximate causation, asking how a behavior occurs or is modified, and two about ultimate causation, why a behavior occurs in the context of natural selection.

1.What stimulus elicits the behavior, and what physiological mechanisms mediate the response?

2.How does the animal’s experience during growth and development influence the response?

3.How does the behavior aid survival and reproduction?

4.What is the behavior’s evolutionary history?

Proximate Causation Example: How do seasonal changes influence when red-crowned cranes mate?

Ultimate Causation Example: Why do red-crowned cranes reproduce in spring and summer?

Fixed Action Patterns

-fixed action pattern- a sequence of unlearned acts that is essentially unchangeable and, once initiated, usually carried to completion.

One example of a fixed action pattern is prominent in male stickleback fish. The male sticklebacks have red bellies and they attack any other males that invade their territory. Scientists observed that male sticklebacks acted aggressively when a red truck was passing a tank of them. As it turns out, the males will not attack fish lacking red coloration, but they will attack anything, even unrealistic models, if they contain any red at all.

The trigger of this aggression is known as a sign stimulus.__________________________________________________Kinesis and Taxis: -Kinesis is a change in activity or turning rate in response to a stimulus An example of kinesis is when sow bugs become more active in dry areas and less active in humid areas. Note: they do not move toward or away from a specific condition. They are more likely to leave a dry area and encounter a moist one.

Taxis-Taxis is an oriented movement toward or away from some stimulus. An example of taxis is when trout automatically swim or orient themselves in an upstream direction (toward the current).

-MIGRATION- a regular, long-distance change in locationHow do animals find their way? -Some animals track their position relative to the sun -Problems with this approach come about when clouds cover up the sun (and the north star for nocturnal animals) -However, evidence suggests that some animals have circadian clocks, internal mechanisms that maintain a 24-hour activity rhythm or cycle.-There are two competing hypotheses for another way that animals find their direction: -Earth’s pull on magnetite-containing structures triggers transmission of nerve impulses to the brain. (pigeon study-by sensing their position relative to the Earth’s magnetic field, pigeons and other animals can navigate without solar or celestial bodies) -Animals are guided by the effects of Earth’s magnetic field on photoreceptors in the visual system. (birds require light of particular wavelengths in their daytime or nighttime environments to orient themselves)

Animal Signals/Communication-A stimulus transmitted from one animal to another is called a SIGNAL. -Example- a male fiddler crab generates a stimulus in female crabs by waving his claws. - Four types of communication (in a stimulus-response chain) are necessary for fruit flies to mate. 1. Visual communication2. Chemical communication3. Tactile communication4. Auditory communication

51.1 Questions

1.Give an example of Kinesis. 2.What is one hypothesis of how animals

find their way when migrating? 3.Name two of the four types of

communication necessary for fruit flies to mate.

51.2 Learning establishes specific links between experience and behavior

● Innate behavior- developmentally fixed this way, ex. smiling, walking, nursing

● Tinbergen’s second question “How does the animal’s experience during growth and development influence the response?”

● An approach to answer this question is a cross-fostering study.

● Babies from one species are placed in the care of another, the amount of change in the babies’ behavior helps measure how much environment influences behavior.

● Example- mice, one species is aggressive the other less so

Learning: modification of behavior based on specific experiences

● Imprinting- includes both innate and learned behavior, formation at a specific stage in life of a long-lasting behavioral response to a particular individual or object.

● Diff. from other types of learning- has a sensitive period

● In this period, the babies imprint and learn basic behaviors of their species and the parent learns to recognize their babies

● If the bonding doesn’t occur the parent will not care for the baby

Who is my mommy? How do babies know what to imprint on?

● Experiments of different types of waterfowl show that they don’t innately recognize a “mother”. They identify with the first thing encountered with key characteristics. ex. the imprinting stimulus for greylag geese is a nearby object moving away.

● These goslings imprinted on Konrad Lorenz. They showed no recognition of the biological mother.

Spatial Learning and Cognitive Maps

● Every natural environment is different- nest locations, food, hazards, mates etc.

● An organism's fitness is enhanced by it’s ability for spatial learning.

● the memory that reflects the environment's spatial structure. ex. digger wasps, knew which burrow was theirs by landmarks

● A sophisticated form of spatial learning is cognitive mapping

● A representation in the nervous system of the spatial relationships of objects in a animals surroundings. ex. Clark’s nutcracker bird- seeds hidden halfway between

Associative Learning

● Bluejay eats a monarch butterfly, because of milkweed the bird vomits soon after. Bluejay learns not to eat monarch butterflies.

● This is called associative learning- ability to associate one environmental feature with another.

● Laboratory studies use it, involves classical and operant conditioning.

● Classical- ring bell before feeding, salivates when bell is rung

● Operant- trial and error, animal learns to associate a behavior with a reward or punishment, and avoids or repeats it.

Cognition and Problem Solving

● Most complex forms of learning involve cognition● The process if knowing that involves awareness,

reasoning, recollection, and judgement.● Many groups of animals, like insects, show cognition

in controlled studies. ex. Bees, rewarded for choosing same as stimulus,when pattern changed, still chose same as stimulus, samefor different.

Cognition and Problem Solving cont.

● Problem solving- the cognitive ability of devising a method to proceed from one state to another in the face of real or apparent obstacles.

● ex. chimpanzee is in a room with boxes on the floor and a banana hung out of reach. Chimp will stack boxes to reach food. Is highly developed in some mammals, and also varies with individual experience and abilities.

Social Learning

● Many animals learn to solve problems by watching other individuals.

● This is called social learning, ex. Mr. Wahl and math problems, chimps learning how to crack open pine nuts

● Social learning forms the roots of culture.● Defined as a system of information transfer

through social learning or teaching that influences the behavior of individuals in a population.

● Cultural transfer can alter behavioral phenotypes and influence the fitness of an individual.

51.2 Questions

1. What’s an example of a cross-fostering study?

2. What are two ways associative learning is used

in laboratory studies?

3. How does social learning changes human

behavior?

51.3 Selection for individual survival and reproductive success can explain most behaviors

Natural selection refines behaviors that enhance feeding efficiency.● Optimal foraging model-maximize benefits minimize energy

expended and danger● example: northwestern crow cracking whelk(sea snails)

they drop the whelk until its shell breaks, higher expendsmore energy but better chance of a break. Results: there is an optimal drop height, 5 m, the lowest height that stillbreaks the shell.● Predators: Some easy, close food will not be taken advantage of

because of predators in the area-cost benefit

Mating Systems and Sexual Dimorphism

● Promiscuous mating-no strong pair-bonds● monogamous-mates remain together for a long time (1 male, 1

female)● polygyny-single male mates with many females ● polyandry-single female mates with many males

● Sexual dimorphism-the extent males and females differ in appearance, often depends on their mating system.

1. monogamous-very alike,ex seagulls2. polygynous-dimorphic, males are showier and larger, ex elk3. polyandrous-dimorphic, females are showier, ex Wilson’s

phalaropes(bird

Mating Systems and Parental Care

Why do certain animals use certain mating systems?● Monogamous- the young need both parents to care for them so

there is a greater benefit for the male and female to stay together than to separate. ex: most birds

● polygyny- the young do not need the parents to care for them so it is a greater benefit for the males to seek other mates.

● certainty of paternity- young born to a female have to contain her genes but a different male could be the father. It explains why exclusively male parental care in birds is rare. Their mating uses internal fertilization.

● External fertilization-ex fish- COP is higher so males often take full parental care.

Sexual Selection and Mate ChoiceMate Choice by Females1. The female’s mate preferences help determine the evolution of

male behavior and anatomy. ex: selecting based on a showy feature- the males over time will be showier

2. imprinting influence-females take cues from their fathers for choosing mates. ex: if father has is ornamented, daughter will prefer an ornamented mate. If father is not ornamented, daughter will not have a preference.

3. Mate-choice copying-an individual in a pop. copies the mate choice of others. ex: female guppy with no other females present will pick a showy orange guppy. A female guppy with model female guppies present that pick the less showy will also pick the less showy.

4. Why mate choice copying? If other females prefer a certain male that female also wants to mate with him because that means his offspring will be desirable to the population

Male Competition for Mates

Males also can diminish male variation.● Agonistic behavior: a contest between males often based on

strength and size to determine who gains food, mates, and resources.

Game Theory● evaluates alternative strategies in situations where the outcome

depends on the strategies of the individuals involved.Ex: side blotched lizards-males can have an orange throat,blue throat, or yellow throat. Each color means a different thing. Orange- aggressive. Blue-less aggressive. Yellow-sneaky. The success of each depends on the amount of that trait in the population(frequency dependent selection). (similar to rock paper scissors)

51.3 Questions

1.Why are certain animals monogamous? (hint: think of their young)

2.Why do females sometimes copy the mating preferences of other females in their population?

3.Give an example of a species that uses game theory to compete for mates.

51.4- Selection for individual survival and reproductive success can explain most behaviors

Foraging-food-obtaining behaviorThere are observable and interpretable evolutionary changes in behaviors in laboratory populations of fruit fly larvae when foraging for food.Fruit flies that were grown in a dense population tended to travel further than those grown in a less dense area.

Optimal Foraging Model: says that natural selection should favor a foraging behavior that minimizes the costs of foraging and maximizes the benefits Example: Northwestern crows must drop their food from a certain height in order to break the shells. Cost vs. benefits: while flying higher may break the shells faster, more energy is used. Crows have evolved to drop food from the height that minimizes energy loss but also minimizes time spent trying to break the shells.__________________________________________________________________Mating Systems/Parental Care: -Promiscuous- a mating relationship no strong pair-bonds or lasting relationships -

-Monogamous- mates remain together for a longer period of time -Polygamous- an individual of one sex mating with several of the other (often a single male and many females-called polygyny, although some species exhibit the opposite, polyandry) -If the offspring require a large, continuous food supply and attention, a male that stays with and helps a single mate may ultimately have more viable offspring than it would by going off and seeking other mates-this may explain why most birds are monogamous. However, if the offspring can get along okay without their parents, the male dreives less benefit from staying with their partner.

Sexual Selection and Mate Choice-A female that chooses a healthy male is likely to produce more offspring to survive and reproduce (male stalk-eyed flies) - Imprinting can also contribute to mate choice- Agonistic behavior- an often ritualized contest that determines which male competitor gains access to a resource, such as food or

mates. -The outcome of such contests may be determined by strength, size, or the effective use of horns, teeth and so forth.

51.4 Questions

1.What is polygyny? 2.What is an example of the optimal

foraging model? 3.What factors determine whether a

male would do better to stay with one mate or to mate with several females?