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In This Lesson: Unit 2 Animal Behavior (Lesson 1 of 3). Today is Tuesday, September 23 rd , 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?
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In This Lesson: Unit 2 Animal Behavior (Lesson 1 of 3) 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.
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
The second thing you need to know… • Just like Mendelian geneticists studies the phenotypes that emerge from a certain genotype, behaviorists study thebehavioral 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 taxisor 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 automaticand 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:
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). http://obsidianwings.blogs.com/.a/6a00d834515c2369e2017eea7923fc970d-pi Soler, M., Martinez, J. G., Soler, J. J., & Møller, A. P. (1995). Preferential allocation of food by magpies Pica pica to great spotted cuckoo Clamatorglandarius chicks. Behavioral Ecology and Sociobiology, 37(1), 7-13.
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://upload.wikimedia.org/wikipedia/commons/5/5c/Reed_warbler_cuckoo.jpg http://whyevolutionistrue.files.wordpress.com/2011/03/f2_hauber_egg.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.