Today is Tuesday,September 23rd, 2014

Pre-Class:What are those ants doing?

I know it’s a little hard to see, but really, why would ants pile onto each other like that…especially with nothing supporting them?

Also, get a paper towel for you/your partner.

In This Lesson:Unit 2

Animal Behavior(Lesson 1 of 3)

Today’s Agenda

• Behavioral manifestations of evolution.

• Where is this in my book?– Chapter 51.

By the end of the lesson…

• You should be able to distinguish between proximate and ultimate perspectives when analyzing behavior.

• You should be able to separate innate behaviors from learned behaviors, and taxis from kinesis.

• You should be able to describe social behaviors, including examples.

Quick Heads-Up

• Just a quick note to let you know that we’ll be interrupting these notes to do our Animal Behavior lab (Investigation 12) and to learn Chi-Squared data analyses.

Before we start…

• Challenge questions!

The first thing you need to know…

• Let’s be honest: You’ll never know exactly what it’s like to be your dog, for example.

• So, when people talk for their dog, or even just feel a need to ascribe human emotions/thoughts to them, they’re anthropomorphizing.

• Anthropomorphosis is the ascription of human behavior to animals. It’s wrong. Don’t do it.

Think this dolphin is smiling?

http://www.marineland.net/images/DolphinHeader.jpg

Think this gorilla is sad?

http://upload.wikimedia.org/wikipedia/commons/b/b1/Eyes_of_gorilla.jpg

Think this bluebird is angry?

http://www.songbirdgarden.com/store/ProdImages/EK6600-1.jpg

Then you’re anthropomorphizing!

The second thing you need to know…

• Just like Mendelian geneticists studies the phenotypes that emerge from a certain genotype, behaviorists study the behavioral phenotypes that emerge from those same genotypes.– Just like other traits, behaviors that improve

successful reproduction chances will also be selected for.• That ended in a preposition and I have no idea how to

fix it.

The Basic Behavior

• Before we even define behavior, let’s take a quick look at the most basic behavior out there: movement.

• Movement is often a simple response to a stimulus. We call it either taxis or kinesis.– Taxis is a directional response, like how a trout will turn

itself so that it’s facing upstream to catch food as it drifts downstream.

– Kinesis, on the other hand, is non-directional movement.• It’s still in response to a stimulus, just not directed.• Woodlice, for a common example, move less when humidity goes

up. Non-directional.

Taxis or Kinesis?

• A photosynthetic microorganism swims toward the light side of its petri dish.– Taxis (phototaxis)

• Ants exit their colony and wander in search of food.– Kinesis

• Once food is found, other ants follow the trail of pheromones to the first ant.– Taxis (chemotaxis)

• Pillbugs under a recently overturned log run for darkness.– Taxis (phototaxis)

With that in mind…

• Behavior is quite simply anything an animal does in response to a stimulus from its environment.– A stimulus is simply a “cue,” which could be internal or

external.• An internal stimulus might be hunger.• An external stimulus might be a baseball thrown at your face.

• These behaviors can be broken down into two general categories:– Innate behaviors are those with which an animal is born. They

are automatic and do not depend on experience.– Learned behaviors emerge during an animal’s lifetime. They

are variable (they change) and depend on the present stimuli of the environment.

Innate vs. Learned

• Mother birds will feed, almost uncontrollably, the gaping beak of a nestling bird.– They just do it…– …even if the image is

printed on a piece of paper.• However, a learned

behavior is something that can often be trained.– Dog house-breaking, for

example.– More on this later.

http://britishwildlifehelpline.com/Chicks.JPG

Nature vs. Nurture

• All of this hints at the age-old debate of nature vs. nurture.– Is it something genetic, or is it learned?– Homosexuality is, unfortunately, often brought up in this

context.• To that end:– Nurture: Male migratory birds kept in an outdoor aviary in

view of their migrating (free) male counterparts will begin to exhibit homosexual behaviors like allopreening (basically cuddling and grooming).

– Nature: Removing a particular gene in male fruit flies causes them to attempt to mate with other males.

You observe a singing songbird:

• What can you ask about the behaviors observed? You might ask…– How does the bird sing?– What prompts the singing?– Why does the bird sing?

• Ask Maya Angelou that one.

– Numbers 1-2 are proximate questions. They concern the present or near past.

– Number 3 is an ultimate question. It concerns the evolutionary history of the bird.

Proximate vs. Ultimate

• Proximate or Ultimate?– How does photoperiod (day length)

affect breeding in cranes?• Proximate. It’s a “small picture” sort

of question.

– Why do cranes perform a courtship dance?• Ultimate. It’s asking about

something that must have taken generations to evolve.

– Why do cranes breed in spring?• Ultimate. It’s the “big picture”

evolutionary question.

Expanding the debate…• Niko Tinbergen proposed the following “four

questions” of animal behavior.– Let’s use singing songbirds as an example again:

Dynamic View Static View

Proximate ViewOntogeny

How did the bird’s anatomy change as it grew to allow

song?

MechanismHow does a bird’s

anatomy allow it to sing?

Ultimate ViewPhylogeny

How did the bird’s evolutionary ancestors

sing?

AdaptationHow does song allow a

bird to survive and reproduce?

Four Questions of Animal BehaviorCase in Point

• BBC – Vogelkop Bowerbird

The Study of Behavior

• Let’s take a look at the history of ethology, which is a fancy word for the study of behavior, in biology.– At some point we needed to get to the typical cast of

old white guys in biology.• The Big Names:– B.F. Skinner– Ivan Pavlov– Karl von Frisch– Konrad Lorenz

B.F. Skinner: Operant Conditioning• Creator of the Skinner box.

– Sounds violent.• A mouse learns that when it pushes a

lever, it gets a reward – positive reinforcement.– Learned behavior, obviously.

• If the mouse doesn’t push the lever, it may receive an electric shock.

• So operant conditioning is training to associate a voluntary behavior with a certain response.– Operant conditioning has a large share

of trial-and-error learning as the mouse must learn about the lever’s function by simply trying it.

Operant Conditioning Words

• Reinforcement: A reward.– Positive Reinforcement: Giving you something good.• Example: A cookie!

– Negative Reinforcement: Taking away something bad.• Example: If I play a screeching loud sound until you do

something I want.

• Punishment: A change that decreases the likelihood of a certain behavior continuing.

• Example: An electric shock.

Operant Conditioning Demo

• I needs me a volunteer.• This volunteer will have to exit the room briefly.• When s/he returns, s/he will have to guess the

desired behavior determined by the class by doing different things in order to get rewards.

• This is often termed “clicker training” because trainers will make a click sound when the desired behavior is performed, thus edging into a different kind of conditioning.

Ivan Pavlov: Classical Conditioning• Give a dog some food and it’ll salivate

automatically.– An innate, unconditioned behavior.

• Ring a bell near a dog and it probably won’t care for more than a second or two.

• Ring a bell and give a dog food enough times, however, and the dog begins to associate the bell with food.

• Suddenly, you can simply ring a bell and get a dog to salivate.– That’s a learned, conditioned response.

• So, classical conditioning is pairing an innate behavior with a neutral stimulus.

Operant vs. Classical Conditioning

• TED: Peggy Andover – The Difference Between Operant and Classical Conditioning

Learning

• Another principle in learning is habituation/sensitization.

• Habituation is when the response to a stimulus decreases with exposure to that stimulus.– “The Boy Who Cried Wolf”

phenomenon, minus the actual wolf at the end.

http://www.kcet.org/news/rewire/assets_c/2013/10/owl-pigeon-10-25-13-thumb-600x600-62607.jpg

Learning

• Sensitization, on the other hand, is the opposite.– Suppose every 30 seconds you don’t do a behavior I

want, I turn on a red light, then deliver a small electric shock.

– Soon, the sight of a red light may be such a powerful stimulus that it almost seems to cause pain anyway!

• Sensitization is an increased response to a stimulus.

Learning

• One last example of learned behavior: tool use.

• Using tools is NOT an innate behavior. Individuals need to learn to use them by trial-and-error or from other individuals.

• Tool use was originally considered a primate-only thing, until…– New Caledonian Crow video!

Just kidding!

• Here’s the real last example:– The Big Bang Theory

Conditioning

• What do the works of Pavlov and Skinner have in common?– They both concern learned behaviors.– Collectively, they form what’s known as associative learning – the

pairing of stimuli with actions.• Lorenz and von Frisch spent their time more with innate

behaviors.– Lorenz: Birds.– Von Frisch: Bees.

• Before I tell you a little story about the birds and the bees, I need to tell you about the fixed action pattern.

• And before that I need to tell you about the chi-squared test. And other stuff.

Fixed Action Pattern

• The Fixed Action Pattern (FAP) is like the holy grail of innate behaviors.

• FAPs are so deeply rooted that they are automatic behaviors that must be completed once started.

• Case in Point: Niko Tinbergen’s Sticklebacks.

Stickleback FAPs

• Male sticklebacks are highly territorial.• Introduce a sign stimulus into their

territory and they will react predictably.– A sign stimulus is a simplified version of a

more complicated stimulus.• Putting a slender oval model, made of

wood, that has a red “half” is the only stimulus needed to communicate an intruding male to the stickleback.– The stickleback will attack the model.

Stickleback FAPs

• If, instead, that sign stimulus is slightly…uh…distended, and has a greenish belly, it presents to the stickleback as a female.– The stickleback will court the

model.– A lot like what we mentioned

before – momma birds instinctively feeding the shape of a gaped nestling beak.

Other Fixed Action Patterns

• Egg Rolling– Greylag Geese– Move an egg out of Mother Goose’s nest and

she’ll instinctively roll it back.– Remove the egg while she’s rolling it and she’ll

keep making the rolling motion, even without the egg.• After she completes the FAP, she’ll look for the egg

again, but she can’t stop the behavior once started.

– Video!

Other Fixed Action Patterns:Humans

• Yawning:– Once started, a yawn cannot be stopped. Further,

reading the word yawn, hearing a yawn, or seeing someone yawn may induce a yawn FAP.

• Eyebrow Flashing:– Upon seeing someone familiar, humans often

quickly raise and lower their eyebrows. It’s an involuntary reaction to someone familiar.

The Supernormal Stimulus

• A supernormal stimulus is one that is exaggerated beyond natural occurrence.

• Examples:– Mother birds that feed models with the reddest

and widest beaks.– Lipstick in humans being even more attractive

than realistically red lips (?).– Birds that prefer to incubate the largest and most

gray-speckled eggs (Tinbergen again).

Soler, M., Martinez, J. G., Soler, J. J., & Møller, A. P. (1995). Preferential allocation of food by magpies Pica pica to great spotted cuckoo Clamator glandarius chicks. Behavioral Ecology and Sociobiology, 37(1), 7-13.

http://obsidianwings.blogs.com/.a/6a00d834515c2369e2017eea7923fc970d-pi

Konrad Lorenz

• Lorenz noticed that baby birds frequently would imprint upon whatever moving object they saw first, animate or not.

• Imprinting is when juvenile organisms come to see another…thing…as a parent.– In the wild, typically they first saw their

mother in the nest.– Lorenz demonstrated that baby birds might

follow humans or even inanimate objects if they saw them first instead.

– Imprinting is also irreversible.

Imprinting’s Value

• Today, biologists often use imprinting as a means of conservation.

• Cranes, for example (why do they keep coming up?), have been imprinted on pilots wearing crane costumes and taught migratory routes that would keep them out of danger.

Imprinting in Film

• Even the 1996 movie Fly Away Home, starring a very young Anna Paquin, depicted the same thing!– Don’t ask if we can watch it.

http://www.teachwithmovies.org/guides/fly-away-home.html

Critical Period• Imprinting is also a great example of a behavior that is learned, yet

also time sensitive.– Imprinting only occurs in the first few moments of a nestling’s (visual)

life.• Therefore, imprinting only occurs during a critical period, before

or after which no imprinting can happen.– In humans? Language learning. In birds? Songs.

Critical Period: Case in Point

• The cuckoo is a brood parasite.– Mama Cuckoo lays her eggs in other birds’ nests to let them take

care of the young.– Because of the surrogate mother bird’s fixed action pattern, she

doesn’t know the egg isn’t hers. She’ll incubate it just the same.• Cuckoos, once hatched, don’t really have a “song.” They

learn the song of their surrogate mothers!– Weird Fact: Cuckoos also lay eggs that nearly precisely match the

surrogate’s eggs, and parasitize the surrogate breed’s nests only.• There are, in a way, different “versions” of female cuckoos.

– Tying it all together: Because cuckoos are actually taking advantage of another bird’s FAP, they are engaged in what’s known as code-breaking.

Cuckoo Photos

http://whyevolutionistrue.files.wordpress.com/2011/03/f2_hauber_egg.jpg

http://upload.wikimedia.org/wikipedia/commons/5/5c/Reed_warbler_cuckoo.jpg

One last thing on cuckoos…

• Cuckoos also provide us an opportunity to discuss the concept of cross-fostering.– This is an elegant method of determining whether something

is genetically or behaviorally driven.• Shortly after birth (or as eggs), switch the young around

and have them raised by different parents.– Cuckoos automatically do this, remember?

• So a cuckoo’s appearance, which is consistent with all cuckoos, is genetic (“nature”).

• But, a cuckoo’s song is learned (“nurture”) because it varies based on its environment.

Classic Experiment: Cross Fostering• Rat pups that are licked by their mothers grow up to be

calm adults.• Rat pups that are not licked grow up to be anxious

adults.– Is it that mother rats with poor social skills passed on their

poor social skills to their high-anxiety pups?– Alternatively, is the licking behavior the sole determinant of

rat “well-adjustedness?”• Cross-foster!– Sure enough, if you take rats born to a mother that does not

lick her young and have them raised by a mother that does, they grow up to be calm just the same.

• Rat lickin’ video!

Back to innate behaviors…

• Unlike birds, a lot of bee behaviors are innate.• Insect song (like crickets) is often completely

fixed.– You can cross-foster all you want. Genetics

determines their patterns.• Additionally, many innate behaviors are also

social behaviors, and this is where Karl von Frisch comes in.– Social behaviors are those that are exhibited

between individuals.

Social Behavior Summary Slide

• Communication and Language• Agonistic Behavior• Dominance Hierarchies– This is the one your teacher studied in college.• Represent!

• Cooperation• Altruism

Communication and Language

• Bees (as discovered by Von Frisch) do a “waggle dance” to communicate food locations.– Waggle dance video!

• Whales communicate via low-frequency sound across ocean basins.

• Communications are sometimes learned (humans, birds), sometimes innate (bugs).– Case in point: French crows and

American crows have different alarm calls.• FYI, that photo is a blackbird.

Communication and Language

• There are other forms of communication too, besides the auditory.– Visual (fireflies, for example)– Chemical (pheromones – hormones released

outside the body)

Pheromone Examples

• Female mosquitoes use CO2 concentrations to locate victims by their exhalations.

• Spiders sometimes use moth sex pheromones (allomones, since they’re from a different species) to lure prey.

• Big cat territory marking.

Agonistic Behavior

• Agonistic behaviors are any fighting-related behaviors, whether it’s aggression or submission.– Think males head-butting each other for a mate.

• That’s how I met my wife.

– Typically, agonistic behaviors don’t result in long-term harm (but they can).

– Typically, agonistic behaviors occur among males (but they can be among females too).

Agonistic Behavior Example

• Here’s a gorilla doing the classic chest-beating agonistic behavior.

• Many times, animals will simply intimidate one another and not actually fight.

• For another example…TRANSFORMER OWL! (Southern White-Faced Owl)

http://hoothollow.com/Image%20Super%20Folder/Images%20-%20Gorilla%20and%20Rwanda%20Superfolder/2010%20Joe/Mountain_Gorilla_5x3.jpg

Dominance Hierarchies

• Dominance hierarchies are social rankings.– Also called a “pecking order”

(for quite literal reasons).– Typically among males.– Most dominant males often

have the best access to food/mates.• Why am I painting the bird’s beak

in that picture?• We set out to determine whether

males respond to supernormal stimuli, but instead found stable dominance hierarchies.

Cooperation

• Like the word suggests, cooperation is working together for a common goal.

• Importantly, all cooperating individuals will share in the benefit, so each has a personal interest as well.

http://www.factzoo.com/sites/all/img/mammals/canids/wild-dogs-hunting.jpg

Altruism

• Okay, this is a weird one. Let’s slow down a bit.• Altruistic behaviors are those in which the

“performer” of the behavior incurs a negative impact on fitness, while the “receiver” of the behavior gains fitness.– WTF?

• Altruism is at first quite a dilemma for evolutionary biologists as there’s no reason for this to exist.– Why would anyone lower their own fitness?

Altruism

• Let’s add a couple more examples:– Vampire bat allofeeding.• Not all vampire bats successfully enjoy a blood meal each

night.• Those that did feed will sometimes regurgitate some of

their meal and feed a neighbor in their group.

– Ground squirrel guard duty.• Some individuals act as lookouts.• Doing so puts them at additional risk, and making an alarm

call further calls predatorial attention to toward them.Roberts, G. (1998). Competitive altruism: from reciprocity to the handicap principle. Proceedings of the Royal Society of London. Series B: Biological Sciences, 265(1394), 427-431.

Sherman, P. W. (1985). Alarm calls of Belding's ground squirrels to aerial predators: nepotism or self-preservation?. Behavioral Ecology and Sociobiology, 17(4), 313-323.

http://images.nationalgeographic.com/wpf/media-live/photos/000/005/cache/common-vampire-bat_505_600x450.jpg

So…why do they do it?

• It’s called kin selection.• Although the altruism “giver” slightly lowers

his/her chances of survival, the animals that behave altruistically usually live in groups of closely-related individuals.

• In other words, they’re still helping to ensure the survival and passing-along of their genes, even if they’re slightly different.

Aside: Altruism and Morals?

• What if there’s something else at play here?• Recent research is indicating there may be

something “higher” going on.– Altruism – NOVA

Chi-Squared Analysis

• Now that you know all these cool behavior-related things, you’ll also need to know whether you’re actually seeing a change in behavior.

• This is when we will explore the idea of a statistical test that will quantify whether a result is significant. Remember that?– This is not just an animal behavior thing.– This test can be extended to many different studies to

determine whether you’re actually getting a real change or if just chance is at work.

– Here’s where I switch PowerPoints to “Chi-Squared Tutorial,” found in the “Fact Sheets” section of the website.

Closure

• If I train my dog by putting up an invisible fence (one that delivers a small electric shock when the dog passes a certain point), what kind of training am I using?– Operant conditioning.

• If, instead, I train the dog by offering rewards periodically whenever the dog remains within the yard, what kind of training am I using?– Still operant conditioning.– Classical conditioning would have me pairing another stimulus

to a natural one, like if I made a click sound prior to giving the food.