Change topic

• Enough on Proximate causes, interesting and a lot of work.

• Basics: Stimulus: effector: in between: behavior• What we will look at now is the behaviors

themselves! Will drift back to proximate causes but main focus will be behaviors

• First distinguish between two major categories of behavior: Innate (instinctive) vs Learned

Innate behaviors

• Used to make sharp distinction between innate and learned behaviors.

• Innate: as instinctive indicates, behavior that is “born with you” and can manifest itself without learning it.

• First proposed by Konrad Lorenz early 1900’s

Fixed action pattern

• One of the standbys of innate behavior was the “fixed action pattern”

• Defined as a behavior, once stimulated to start will continue to its end, even if the original stimulus (innate releasing mechanism)removed.

• Greylag goose of Lorenz. Used to be the Classic example!

• Now, hardly heard of!!

Innate behavior

• Why??• Lot of controversy over this concept and in fact

can’t even be found in many new books!• Here we touch on it for both historical reasons

and just in case it becomes in fashion again!• Fairly stereotypic behaviors within species and

across species. • Would manifest itself in isolation, no outside

environmental influence, or at least we think so!

Innate Learning

• Many argued that can’t isolate from all possible environmental influence, so can never be sure….

• A lot of circular arguments made: graduate students trying to make a name for themselves!

• U.S. vs Europe (reductionist vs holistic)• Yet we do recognize that behavior has a

genetic basis!

Innate behaviors

• And that where it stands to day, so far… most accept that behavior has genetic basis (or at least control!!), just arguments as to how much!!

• What are you to do?

How to view innate vs learning

• Best visual model is: all born with a framework (skeleton) of behaviors or behavioral capabilities: a lot due to anatomy and physiology: a dog may want to climb a tree but it will never learn how to do it!

• This defines the range of possibilities. The actual behavioral repertoire (fleshing out of skeleton) individual develops depends on experiences (learning) it has.

Phenotypic plasticity

• Some equate it to “phenotypic plasticity”• Ability to change phenotype under different

environmental conditions.• Example Bryozoans (spines in presence of

predators but not in absence)• Example Locust (solitary vs migratory types:

different structure AND different behaviors!)• Maybe Lamarck was right!!!

Behavioral plasticity

• Behaviors are more changeable than anatomy or physiology!

• Although the behavior itself may not be genetically transmitted, the ability to do so is AND as we will see, can be transmitted socially.

• Still all quite confusing!! Mental gymnastics!!

Blah Blah Blah….

• What we do know for sure is that behaviors CAN change with experience, animals can learn.

• So now looking at those modification from experience: learned behaviors (Chap. 4)

Learned BehaviorsWhat is learning

• First must address the question of what do we mean when we talk about learning?

• Or definition of learning:• A relatively permanent change in behavior as

a result of experience.• One could argue: where did that original

behavior come from?? Innate, Genetic?• Lets not go down that road!!!!

Learned behaviors (chap 4)

• Best to start with the behavior that enables many others: Learning behavior

• Identified earlier as a source of gaining behaviors

• Is a behavior in itself!

Individual learning

• Make a distinction between how an individual learns from experience and social learning, learning from other individuals.

• Here we deal with individual learning• Three interrelated question:• 1) How do animals learn• 2) Why do animals learn• 3) What do animals learn

How do animals learn??

• Psychologists: processes underlying learning.• Three types of experiences that lead to

learning• 1) single stimulus• 2) Stimulus-stimulus• 3) response-reinforcer

Single Stimulus

• Single stimulus given an animal:• E.g. blue stick to a rat in a cage.• Rats will notice because of novelty.• If consistently notice it: call sensitization to

the stimulus• If eventually ignores it: called habituation.• Two possible learned responses to a stimuls

Single Stimulus

• Sensitization is good If stimulus is important and may help animal associate this stimulus with other cues.

• Habituation is good in that it helps reduce the background “noise” (bombarded with stimuli constantly) and enable response only to those of importance

• Can be disadvantage if become habituated to a cue that later becomes important! Predation e.g.

Stimulus-stimulus

• Here we see how an animal related TWO stimuli

• Example: pair blue stick with odor of a cat.• Cat reacts to odor initially but…• Eventually will hide just when blue stick is

spotted: associates blue stick with cat..• Pavlovian or classical conditioning.

Terms…Terms..Terms!

• Things getting complicated so need terms to keep it straight!

• 1) First stimulus: Conditioned stimulus (in itself, does not elicit a response

• 2) Second stimulus: Unconditioned stimulus (this is one that would normally elicit a response, even without training.

• 3) Conditioned response: This is reaction of animal to conditioned stimulus AFTER it has associated it with unconditioned stimulus

Terms…terms…and more terms!

• A few more terms associated with this.• 4) Appetitive stimulus: stimulus that is

considered positive, pleasant, or rewarding, e.g. food, potential mate, safe haven, etc.

• 5) Aversive stimulus: Opposite – unpleasant, e.g. shock, noxious odors, etc.

• 6) Excitatory conditioning: positive relationship – first stimulus leads to or predicts the occurrence of the second

And more…..

• Inhibitory conditioning: If first predicts second event will not occur: Huh?

• E.g. if blue stick becomes associated with NOT getting food when rat would normally get it.

• No blue stick, will get food.• Blue stick, no food.• Can add second and even 3rd and 4th

conditioning stimuli!!!

What does this all mean!!???

• Basically it means that animal can associate one stimulus with others AND to predictable outcomes (presence of cat, getting food or not….)

• Through this association it “learns” how to modify its behavior

• So the ability to associate stimuli with outcomes is important part of learning behavior.

Response-Reinforcer

• This associate ability becomes more evident in third type of experience.

• Commonly called: Instrumental conditioning or Operant or Goal-directed learning.

• Response of animal is reinforced by a reward or punishment

here

How different from Pavlovian?• Animal takes some action first, stimulus comes

second. Associates outcome with stimulus rather than stimulus with outcome

• Classic is rat pushing lever to get food.• Can get complicated!• Law of effect: If response in presence of stimulus =

satisfying event: association between stimulus and response strengthened. And visa versa!

• Skinner and “Skinner box” biggies in this area

Summary on how they learn

• Why is this all important?• We know animals (us!) learn from experience.

What we need to know is how is that accomplished?

• This then helps us understand how, why, and when certain behaviors may occur

Summary

• Results so far: A feedback system where, • 1) animal does something and gets a result

and it remembers this• 2) something happens to animal and it

remembers circumstances (stimuli) under which it happened

• So two biggies: association AND Memory!• How memory works, is anyone’s guess!!

Memory

• Without it learning is impossible• Still don’t know exactly how we physically

store info, some three dimension electro-physical process!!??/

• What we do know is:• Memory is selective! (extinction curves)• Memory capabilities vary intra and inter-

specifically: some better than others

Memory

• Brain-memory-learning is the main genetic link between genes and behavior.

Why animals learn

• Ok, some idea of learning process: carrot and stick!

• Why do they learn?• Simple answer is that it has a “survival

advantage”• But not as simple as that or is it??

Why learn

• The fact that memory is selective can provide clues:

• - Receive thousands/millions of stimuli• - Make thousands of associations• - Some we remember/others we forget• - Some we remember longer than others• Reflects importance of the associations with

environment

Why animals learn?

• Behavior is interface of animal with its environment: a changing environment!

• With this interface, animal needs to capture energy and avoid loosing it!

• In capturing energy (food), learning important way of increasing foraging efficiency – reduce foraging time

Why animals learn

• In capturing “new energy” (reproduction), learning increases chance you will participate. (not just trees releasing pollen!).

• In avoiding loosing energy, it is helpful to learn what are safe vs dangerous areas!

So why do they learn?

• Helps maintain the energy capturing machine under environmental conditions.

• Indeed if they do not learn, they are dead meat!!!

What do they learn?

• Ok, out of those millions of stimuli and associations, which, if any, are important to learn about??

• Obviously rest of book is on the different behaviors that have developed based on stimuli received!

• Here is a general treatment of the major categories, which we will then look in detail later.

What do they learn?

• List of things important to their survival!• 1) learning where home is located!

• What this involves is all the various behaviors we will cover in Chapter 13!

• As mentioned, behaviors are interface of animal with its environment

Call Home!!!

• Animals live in the environment and so it is important to learn about it.

• Bird and other migrations: learning migratory routes

• Habitat selection: learning what is the appropriate habitat to live in!!

• Will see this is one of THE most important behaviors to learn for many species!

What else?

• 2) Learning about your mate!!!

• Obviously important for the capture of future energy for the species!!

• Two chapters devoted to this!! (6 & 7)• Need I say more??

Next on the list…

• 3) Learning about familiar relationships (Chap 8 & 9)

• Related to the previous one.• Getting into social behaviors• Interfacing with others of the same species.• Recognition, cooperation, etc.

• We have to “deal” with relations!!

Next?

• 4) Foraging!! Looking for the energy that keeps us alive!! (chap 10).

• 5) Closely related is anti-predatory and predatory behavior (Chap 11). Learning how to avoid being eaten can come in handy!

Still more

• 6) Aggression: (Chap 14). Learning how to be and when to be aggressive has survival advantages!

• 7) Fear! Not listed but is a very helpful behavior to learn, especially in anti-predator context!

• 8) Play (chap 15) what is its role?

So there

• As mentioned, these cover in a broad sense all that an animal learns and as we will see all play a role in aiding in the survival of the individual and the species.

• Before we go to these behaviors, need to cover that other form of learning: Cultural transmission

Cultural transmission (chap 5)

• Talked about how an individual learns from external stimuli

• What good is learning something new if you can’t share it!!

• Why share it? Can aid in survival of relatives!! So sharing info has a survival advantage for your genes!!

Cultural transmission

• This sharing of information is cultural transmission.

• Defined: Transfer of information from one individual to another via social learning or teaching (can be within or across generations)

• As mentioned: this is a form of evolution without genes!

Cultural transmission

• Form of learning: social learning• Obviously similar to individual learning in

terms of pathways, etc. • But involves learning from others• Lots of non-human examples:• Japanese macaques most noted• First was when one female learned how to

wash her potatoes to remove sand and dirt

Cultural transmission

• Others followed suit and began to wash their potatoes.

• Since then many more incidences noted.

• Characteristics of cultural transmission:• 1) can spread quickly• 2) more likely to spread to younger ones• 3) seems to be some resistance to adapt in

older individuals!!

here

Importance of cultural transmission

• How does it differ from individual learning?• Individual is often trial and error• In cultural transmission, emphasis is:

individual to individual• Way of transmitting individual learned

behaviors, even after initial learner has died• Way of building on experiences: one learns

and transmits a behavior, others improve it

Social learning

• As mentioned, basis of cultural transmission is social learning.

• Various forms of social learning, two common ones are Imitation and copying

Imitation

• Must involve new behavior learned from others and must involve new spatial manipulation: Macaque and potatoes.

• The keys are a new behavior and then undertaken by learner elsewhere

Copying

• One animal repeats what it sees the other do.

• Differs from imitation in that need not be a new behavior.

• Subtle difference but…

Teaching in animals

• So far, talking about an animal being observed doing something and then it is imitated or copied by others

• No intent on the first animal (the model) in transmitting this information, passive role

• Evidence that many animals take active role in transmitting information: Teaching

• Implies one acting as instructor and others acting as students.

Teaching in animals

• Teacher must provide immediate benefit to students but not to itself.

• Must “teach” only to naïve individuals• Must impart new information faster that

students might otherwise receive it.

Examples of teaching

• Female cat bringing live prey to young• “helper” meerkats removing stingers from

scorpions and then letting young catch and eat them

• Many more usually females “teaching” their young.

• This is a common theme found

Other commonalities?

• Usually are either “opportunity teaching” or “coaching”

• Opportunity teaching: teacher places student in situation conducive to learning

• Coaching: Teacher directly alters behavior of students by incentives.

What next?

• Modes of cultural transmission (direction of the transmission)

• 1) Vertical• 2) Horizontal• 3) oblique

Vertical cultural transmission

• Information is transmitted across generations from parent to offspring.

• Examples: Lots! All that “kids” learn from parents

• Male birds learning song from good old dad• Females learning song preferences from

mom!

Horizontal cultural transmission

• Learning from your peer group: Many animals segregate based on age (like humans!) and information is passed among them.

Oblique transmission

• Across generations but not parent/offspring• Young get info from nonparent adults.• Common in species with little parental care• Many of our fears seem to be acquired this

Summary• Cultural transmission is a way of passing

information on to other individuals• Avoids reinventing the wheel• Way of improving the wheel!• Can be done passively: social learning• Can be done actively: teaching

(opportunity/coaching)• Occurs along different pathways:

Vertical/horizontal/oblique

Next: communication behavior (Chap 12)

• Why we jumping ahead?• Saw that a lot is learned via cultural

transmission• This transmission includes sight AND sound!• So, logically next behavior to consider would

be communication!• Communication includes sight and sound

Communication behavior

• Defined: transfer of information from a signaler to a receiver.

• Many of the communicative behaviors are part of the larger behavior we will be looking at: stress calls are part of “anti-predator” behavior

• Will not concentrate on the overall behavior (which we will cover more in detail alter)

• But the role communication plays in it.

What is important?

• Is it honest??• Are the individuals accurately conveying

information or are they trying to manipulate others?

• Not just a problem with humans!!

Honesty

• Answer is yes and no.• Sometimes communication is “honest”,

conveying correct info• Sometimes use communication to “get what

you want”!

When to be honest?

• Classic ethological approach: both parties will be benefiting from information exchange

• With this, less exaggerated signals (conspirational whispers)

• Should be used in kinship communication

• Unrelated, often hard to envision when both would benefit.

• Should occur when impossible to fake information: Toads, only large males can make deep croaks

• When costly to fake: length of song, energy intensive and only healthy ones can do it.

When to lie!

• Dawkins and Krebs suggested: most times!!• Communication in general is to convince

recipient of something. • Advantage to “beefing up” our resume!• Selective advantage to convincing recipient

you are something more than what you are.• Typified by exaggerated signals

Recipient??

• Puts pressure on recipient!• Selection for those who can see through the

lie!• Mind readers and arms race• The better recipient gets at detecting a fake,

the better the fake has to get!

Summary on honesty

• Communication behavior is to convey info between signaler and receiver

• Honesty may not always be the best policy• If send dishonest information, initiates an

arms race• Depends on what trying to communicate• AND cost/benefit to honesty or dishonesty.

Reasons for communication

• Book: effort to solve problems that animals encounter in natural environment

• Help see costs/benefits to communication• Three main problem areas:• 1) foraging• 2) mating• 3) predation

Foraging communication

• Problem: how to coordinate group foraging?• First… Why?• Social species easy to see: work as group and

can more efficiently use a food source

• Not so social species?• Cost/benefit• Cost: you have to share food!• Benefit: if you are “recruited” to food source.• Benefit: Recruiter? Keep track of food source

if you have to leave and food source moves.

How coordinate?

• Special food calls: many species of birds signal food source by calling

• Crows: • Swallows

here

• Physical movements• Waggle dance in bees

• Chemical/vibrational communication: ants• Recruitment phermones:• Methyl 4-methylpyrrole-2-carboxylate• 3-ethyl-2,5 methylpyrazine• Placed along trails

• Vibrational communication

• Stridulation: Moving the ultimate body section (Gaster) up and down.

• Found this conveys info to others about leaf quality.

Problem: how to find a mate?

• As mentioned 2 chapters on this but here we look at it relative to communication behavior

• Two main communication pathways are:• 1) vocal• 2) tactile

Vocal communication and mating:bird songs

• Many species use vocal communication to find and attract a mate

• But birds seem to have brought it to a well defined level: frogs croak, elk bugle, but birds sing!

• Some simple but many quite complex• So will look at them as an example

Birdsongs

• Used for many things species can have one, 10, 100, a 1000 different songs.

• But here we concentrate on those used for mate selection

• Question: How songs are used to attract a mate.

• Question: Why does it work??

Genetic filter

• Thought that songs are a genetic filter females use to select mates.

• One filter may be the number of songs a male can sing! The more songs, the more successful he is!

• Why? More songs: older male or more fit to sing them! Harder to fake!

• Remember, in communication receiver is trying to detect fake!

Song complexity

• Another filter is song complexity:• Evidence suggests that it is not what you say but

how you say it!• Frequency, amplitude, rate of pauses, maximum

note length, etc. All important components that transmit information about mate suitability

• More energetically costly, more likely song is honest.

Tactile communication and mating

• Water striders: produce ripples in water with their legs.

• Like songs, produce different ripple frequencies and amplitudes for different communication.

• Calling mates; courtship: sex discrimination, etc.

Ripple communication

• Each is different, travel across the water and interpreted by females, which then respond accordingly!

• How they use these to determine whether sender is honest or not, not clear yet but likely similar to sound waves of songs

Problem: warn others about predators

• When feeding in groups is beneficial, would be nice to warn others of impending danger!

• Problem is: how, when, and why• How: mostly vocal calls (alarm calls) • Have the advantage of being very specific and

can be transmitted rapidly

When do you warn others?

• Studies of birds show not always!!• Often only intersexual: mates will warn

partner but not others of same sex!• Mate investment• Put a value on who to warn!• Indicates the potential “Why”• - when there is potential advantage to you or

your genes!

Honesty and alarm calls

• We would assume that alarm calls would be “honest”

• Most cases they are, transmitting important information

• However, in some species we find alarm calls being used in a deceptive manner

• The boy who called wolf!!

Deceptive alarm calls

• When would it be advantageous to use a deceptive alarm call?

• Vervet monkeys: low ranking males will do so in potentially dangerous intergroup encounters: to avoid a fight!

• Male swallows will do so if they see their mate with another male!!

Does it work?

• Initially yes!• But like the little boy, if you do it too often,

others will ignore you.• Ground squirrels: If not backed up by seeing

predator, will ignore calls

How many false alarms should it take!

• Obviously there is a danger in ignoring an alarm call: IF the villagers would have listened that last time….

• But how many false alarms are needed?• Depends on danger level, kind of like mimicry:• Depends on sender! Others may get to know

one is unreliable.

Summary communication behavior

• Important in transmitting information to others.

• Can be honest: what you say is what is so.• Can be deceptive: trying to manipulate• Is used to solve problems individuals face.• Depending on problem, depends on degree of

honesty.• If dishonest, can start evolutionary race!

Next: sexual selection (Chap 6)

• Ok, have basic behaviors covered, innate, learning behavior, communication, etc.

• Ready to look at “specialized” behaviors• Ones designed to deal with specific aspects of

an individual’s life.• Again, remember will be a lot of overlap and

at times may seem repetitious.• Can’t pigeon-hole behaviors

Sexual selection

• First we will deal with is behaviors aimed at acquiring more energy for your species: reproduction.

• Various aspects of it, first is selecting who you will do it with!!

• Believe it or not: don’t want to do it with just anyone!

Gene selection

• Reproduction is for passing on your genes• Evolutionary advantage to do it wisely!

• When we talk about sexual selection• Consider:• Intrasexual selection: same sex competing• Intersexual selection: selecting mate

Intrasexual selection

• Darwin: competition for mates important part of reproductive success!

• For most species: males do the competing, at least we think so!!

• Why?

Male competition

• Why:• Males produce millions of sperm and can

potentially inseminate many females at a low energy cost.

• Females: produce 1-<15 eggs/cycle and although can and do mate with more than one male, really only need one male to fertilize eggs.

• Also, energy intensive post fertilization

Bateman’s principle

• 1) females should be choosier be eggs expensive to produce and reproductive success limited compared to male

• 2) should be greater variance in reproductive success of males.

Because there is an evolutionary advantage to being a successful male, evolution would favor competing for success.

here

How do they compete?

• Many forms: familiar with many• Direct fighting is common

Male Competition

• Displays: birds good at this!

Mate choice

• However, not all just male competition.• What is the female’s role?• Used to think it was passive: waiting patiently

on the sideline to see who the winner would be!

• But females have stake in this!• More so than males: it is their ONLY chance at

passing their genes on!

So who is choosing whom?

• Answer: both really.• So we now talk more about Mate choice• we look more not just at the glamorous

battles/displays of the males but more at the often subtle reasons WHY males do what they do, which is often driven by female choice!

• Colorful male birds!

Male secondary sex characteristics

• Why do male lions have a mane?• Why do male baboons have such red butts!!

• It is because it is what it takes to convince a female! So who is doing the choosing??

• Mate choice is a male trying to convince female he is the right one and females evaluating IF that is really the case!

• So we need to look at evolutionary models of mate choice to better see how and why we males have gotten so ridiculous!!

Evolution of mate choice

• Past: looked at flashy males• Today: lots of research into female choice• Underlying assumption of most earlier work is

that female choice is under some genetic control – there is genetic variation in female mate choice behavior.

• Four evolutionary models proposed:

Evolutionary models

Direct Benefits model

• Natural selection favors females who are genetically predisposed to choose mates that provide benefits beyond just good genes.

• Female will choose mate that provide important resources: food, safe shelter, assistance, etc.

Evidence for this model

• Female scorpionflies: choose mates based on the size of prey item they bring. The bigger the better, if you don’t bring anything, you get rejected!

• Nuptial gifts: she eats while they copulate.

More

• Female determines how long they copulate based on size of nuptial gift: again, larger longer

• Longer they copulate, more sperm transferred• What does she get from all this?• Larger gift, longer copulation time, more eggs

produced.• Also provides a meal for her!

Genetic link

• Strong selection pressure on males who can bring large nuptial gifts.

• Finding large gifts is time consuming and dangerous.

• Few can do it, so they do the most mating• Some steal prey by mimicking females• Evidence that females select males based on

resources provided and how it can affect male foraging behavior.

Good genes hypothesis

• Concentrates not on resources females get from males but the quality of the sperm they receive: good genes!

• Good genes: those that code for some suite of favorable traits, which are passed on by a choosey female.

• More indirect benefits than previous• Increased survival of offspring

But…how do you tell?

• May sound good and field evidence that females selecting for other than direct benefits.

• E.g. Pronghorn, females select male based on size of harem…larger he is able to keep, more “attractive” he is.

• But how do females know this is good genetically??

Basic questions

• 1) How can females determine which males have “good” genes?

• 2) If she is using some criteria, how does she know the male is not faking this criteria?? That communication thing again!

Honest males, do they exist?

• Answer the second question first.• Saw in communication behavior• Selective advantage to a male being dishonest• But…selective advantage to female who can

tell the difference!• Arms race that should lead to Honest

indicators of gene quality…but what are they?

Honest indicators of gene fitness

• In general two major factors hard to lie about.• 1) survival capabilities• 2) physical health

• Can be related and both are energy intensive.

Survival capabilities

• How do you tell that your potential mate can give you genes that would enhance survival of offspring?

• You test them!!• Not surprising that for many species, males

have elaborate courting rituals.• Many related to health as we will see.• But some are tests of survival.

Survival tests

• Usually say brightly colored male birds are so to “attract” a mate.

• Why attractive? Assume is a good indicator of health.

• But, could be a test against predation!!

Survival test

• Elaborate courtship rituals:• Brightly colored, singing, and dancing like a

fool!!!

• If you can survive predation attempts, you may have what it takes!

Survival

• Frogs, fireflies, list goes on and on of males putting themselves in danger to attract a mate. Why?

• You would think that evolution would favor safer courtship rituals unless its demanded by the females!

State of Health

• Majority of courting rituals (usually male-male competition) can be considered ways females can judge health of potential mate.

• Not surprising that many involve physical contests.

• Definite filter regarding health of male and hard to fake.

Physical contests

• Leks in grouse, contest for preferred central areas: physical strength.

• AND safety for females for mating!

State of Health• Brightly coloring• Takes energy to produce AND maintain all this.• What is the first thing to go when you feel sick?

Personal hygiene!• So two tests:• 1) do you have genes to grow them/ 2) Are you healthy enough to maintain them?

Bright colors

• Redwing black birds:

Bright colors

• Bright colors may indicate parasite resistance; Sticklebacks

Courtship rituals

• Besides putting yourself in danger, it takes energy to dance around, hop up and down, sing, build things (bower birds).

Odors!

• Evidence some females use odors as indicators of health – good genes.

• MHC: Major Histocompatibility complex• What?• Set of genes related to disease resistance• These are “good” genes to get!!• Combination of genes in this complex result in

different body odors!

MHC

• Found males with dissimilar MHC combinations were more attractive to females

• Also, different odors related to number of genes in this complex and females attracted to males with higher numbers of genes!

Symmetry

• Symmetry of body form: similarity of left and right sides.

• Related to developmental stability• Which is related to ability to adapt to change.

here

• Obviously equating health with genetic well being.