Animal Behavior

Hi. In this lesson, we'll be talking about animal behavior. Now. Behavior is defined as the actions and organism will take in response to stimuli. And this can include interactions with other organisms and the environment. Now, behavioral ecology is going to study animal behavior, and it's gonna be interested in the ecological pressures that influence it. Behavioral Ecologist. They're really going to be interested in asking two types of questions. They're gonna want to know about what they termed proximate causation, which is how behaviors occur in mechanistic terms, like what genetic factors control this behavior or what neurological factors are involved. So they want to know what causes the behavior. And how does this behavior develop, you know, genetically evolutionarily, How did this biochemically physiologically develop now? They're also going to be interested in the why of this. So proximate causation is looking at, like literally, How does this happen? Step by step. In a mechanistic sense, ultimate causation is why these behaviors occur. What function do they serve and how did they evolve? Not in a mechanistic sense, but in terms off how they affected this organisms survival. Right? So we want to know how these behaviors air going to affect fitness. And how did they evolve in the sense of you know what pressures encouraged them and discouraged other behaviors? What events led to them being the behaviors that best served this organism. Now, here you can see an example of, uh, very well studied behavior which is exhibited by geese. When one of their eggs rolls out of the nest, the mother goose will go out and with her head, basically roll the egg back into the nest. Now, this is what we would call an innate behavior. Uh, the goose just does this automatically, and in terms of what causes this behavior, well, it's the stimulus of seeing the egg outside of the nest. And in fact, you could trick a goose by putting something that, you know they'll think is an eggs not actually their egg. But you can fool them into thinking it's their egg, and they'll exhibit this behavior. Now, how did this develop? You know, uh, did this come from dinosaurs, for example? You know, birds did evolve from dinosaurs. Maybe this was, ah, behavior that dinosaurs exhibited, and that's why thes geese air showing it, you know, it's like genetically programmed in them from long, long ago in their ancestors. I mean, I'm just hypothesizing here, but, you know, that would sort of be how did this behavior developed kind of question. Now, in terms of how does this behavior effect fitness? It should be fairly apparent that if the goose returns the egg to the nest, that egg is gonna have a higher chance of survival, meaning more offspring. So ah, behavior like this will obviously increase fitness because it will lead to a higher rate of, you know, offspring reaching viability in terms of how did it evolve? You know what pressures lead to this, You know it. You know, it could have been a variety of things. You know, I could only really hypothesize here, you know, But perhaps it was something like a the nature of the nests caused eggs to fall out regularly or something. You know, it could be something Azaz, simple and silly, seeming as that. Now I said that this was an innate behavior, and behavior is actually run on a spectrum from learned to a Nate and innate behaviors air genetically programmed. Um, they are going to just happen automatically though it should be noted that some innate behaviors will require organism existing in these two clearly defined categories. Now, a great example of an innate behavior is this yawning, and you can see that this behavior has very little variation between the organisms that exhibit it. And we actually would call that a fixed action pattern. Now, some fixed action patterns will be the result of an external que which will call a sign stimulus. Now, obviously, yawning is going to come from internal cues. However, I'm suspicious that yawning is contagious. I don't know if you've ever experienced that. I certainly have. However, in a more serious sense, uh, a fixed action pattern that is elicited by a science stimulus is going to be something like the behavior of the male sticklebacks fish. Now, these fish will, uh, they have red bellies. The males have red bellies, the females don't. So here you can see a male. This is a female no red belly, and the males have this fixed action pattern off attacking anything they see that has a red belly and the red belly. We know to be the sign stimulus because you can put a UN object that looks just like the male fish in there, but without the red belly on it, it's not going to respond to it at all. You could also put an object just like this that you see here that doesn't look anything like a fish but has that readiness to it, and the male sticklebacks will attack it. So that is an example of a sign stimulus, this red belly, and it's going to illicit that fixed action pattern of the fish attacking it. With that, let's go ahead and flip the page.

learning is going to involve the acquisition or modification of a behavior, and it's gonna be due to the result of experiences. Learn behaviors usually involve some type of choice and a cost benefit analysis in that choice. Now, spatial learning is a special type of learning that establishes a spatial memory of the organisms environment. This is sometimes referred to as a cognitive map, a mental representation of the spatial information, and usually it involves relative space between objects. And we could see a nice example of that behind me here in this water maze where you basically put a mouse in it and you give it some type of landmark, and you have a hidden platform that it constabulary in the water, and it's basically just gonna swim around until it finds that platform. But then, based on where it knows that platform is relative to that visual landmark, the next time you put it in the tank of water, it'll swim right to the platform because it will know that it's there based on its spatial memory or rather, its cognitive map. Now there's a special type of learning called imprinting, and this is a time in an animal's life when it's gonna learn the characteristics of a stimulus. Usually you see this in the form of a child imprinting their parent. So they're going to learn the stim stimuli associated with that parent, be it experience, appearance, smell, sound, that sort of thing. And this is usually Onley possible during what's known as a sensitive period. And generally this is a very young age for the organism, and the result, as you can see, is the child will know what its parent looks like, or what its parent is based on certain stimuli. And you know, for example, in the case of thes ducklings will follow the mother duck around because they've imprinted the mother duck. Now this can sometimes go awry in some funny ways, and you'll see examples of ducklings, imprinting humans or even inanimate objects. Actually, and you know, that's that's basically this system kind of going haywire. However, it's supposed to work like this. Now, a signal is going to be a stimulus that is transmitted from one organism to another and one type of signal that we've looked at in other areas. Pheromones, thes air chemical signals released to the environment that allow organisms to communicate with one another. And you'll very often see these used by insects like bees to communicate with each other. Now communication is just the transmission and reception of signals between animals, and these don't just have to be chemical signals. They can be visual signals, auditory signals, uh, olfactory signals like smells, all that sort of stuff. Now there's an interesting type of communication behavior that you'll see, for example, in fruit fly courtship behavior. It's called a stimulus response chain, and basically here the communication behavior is such that each signal that's sent by an organism is going to serve as the stimulus for the next response by the other organisms. So, essentially, here you can see in the courtship the, you know, female fly is going to sort of Orient itself. And then these two flies they're going to do kind of like a dance, and they're going thio, uh, send these signals to each other that act as stimuli for the next behavior. The next action in the behavior. And this will eventually lead Thio. Yes, well, extensively anyways, mating as you can see here Now, it should be noted that not all communication is what we might call honest communication. Some is intentionally deceitful with the intention of fooling and organism. For example, you'll see, uh, possums playing possum, right, pretending that they're dead. That is a deceitful type of communication. However, it should be noted that deceitful communication tends to be most effective within a species as opposed to between species. And you'll see this in a bunch of really funny ways, especially with mating behaviors where, for example, they'll be, you know, some males that will be like big and strong and kind of like push away the other males from a female. But then there'll be some males that are deceitful, and they'll sidle up to like the female organism and pretend toe look like a female themselves, so that the the big, tough male, who's kind of throwing his weight around doesn't realize that they're actually a male and they'll mate with the female right under the big guys knows. I mean totally awesome funny stuff that you see in nature. Alright, with that, let's go ahead and flip the page

foraging is the term for food seeking behaviors, and these can include searching for food, identifying food, capturing food and actually eating the food. So it's quite a comprehensive umbrella term for basically all things food related. Now I want to give you an example of a very interesting genetic mechanism that controls Cem foraging behavior. And this involves it's kind of gross, but fruit fly larva. Now they're gonna have this gene called four for Forage, and this is going to control their foraging behavior. There's going to be to a Leal's for this gene for our which is the rover Leela's. It's called in four s, which is the sitter Lille. Now, the way this gene controls behavior is that Rovers, as they're termed dudes with these wheels, will travel twice the distance for food as sitters will, and you can see a model of that here. The rovers are gonna move around a lot further than will the sitter's now, in terms of natural selection, low population densities will actually favor the four s Jean because in low population densities, you don't need to bother expending this much energy to find your food. However, Rovers will do better in other situations. For example, in certain high density population situations, foraging further will actually potentially lead to greater success in finding food because of all the competition with the other organisms. Now the optimal foraging model basically says that because natural selection favors foraging behavior that, uh, that is going to minimize costs and maximize benefits, we're going to see organisms perform their foraging in this way. You know, food is gonna be such a strong factor in natural selection because it's so essential to survival. So behavior surrounding obtaining food are going to be heavily, heavily shaped by natural selection. And so we're really going to see thes, you know, patterns that optimize thief, forging behaviors of organisms that allow them to minimize their costs and maximize their benefits. And that's what this graph here is trying to represent. Ease for energy. So we want Thio maximize the energy we obtain and, you know, for the amount of, uh, you know, expenditure. We have to dio in terms off finding that food. So you know that's going to involve putting yourself at risk and, you know, actually expending energy to find the food, like if you're predator and you have tow, run and jump and bite this animal in the neck a bunch of times before you get to eat. So there's always really gonna be this risk reward balance between energy expenditure and energy gain for organisms. And it should be noted that predation is gonna pose a great risk for a lot of animals when they're foraging and it's going to influence their behavior. For example, there are this, uh, this type of deer mule deer. Now, you know, dear, they're like the rats of the woods. They just just gonna go eat vegetation and stuff just everywhere. And they can really eat vegetation wherever they want. They could eat it in the forest. They could eat it at the edge of the forest, but they tend to eat it in the edges because of the influence of predation. Thes mule deer are at a far lower risk of being eaten by mountain lions when they're on the edges of the forest, as opposed to when they're in the forest. So even though there's food in all of these places, they're actually going to selectively forage in those edge environments. Now the main point to take away here is that animals are always going to maximize their feeding efficiency and balance their risk. And this is going to involve the risk of, you know, injury, the risk of predation and the risk of wasting a bunch of energy, you know, to get the optimal result. All right, let's go ahead and flip the page.

mating behaviors include attracting mates, competing for mates and caring for offspring. Mating systems described the way in which mating and sexual behavior is structured. Two examples of this are monogamy and polygamy. You can see an example of monogamy right here with these albatross, and this is when one male mates with one female and they stick together. Polygamy, on the other hand, is when an individual of one sex will mate with many individuals of the opposite sex, and this could go both ways. This could be a male mating with many females or a female mating with many males. Now, sexual selection is the type of natural selection in which members of one sex choose mates. This can involve one sex choosing a mate of the opposite sex, for example, what you see here in this mating display put on by this bird of paradise, where this very plain looking female is basically going to see whether or not she's impressed with this dude's stuff and shoes, whether or not she wants to meet with him now, this can also take the form of competition between members of the same sex, for example, Uh, Rams, you know, which will smash heads to compete for who gets to mate. Now females tend to choose their mates when they're the ones doing the choosing, based on signs of fitness and health. Now, even though this bird's dance and its feathers might not seem like obvious signs of fitness and health, the plumage, color and its ability to perform those types of you know precise movements can actually be indicators. In a sense, a new, indirect sense of this animal's health and fitness Now mate choice copying is an interesting phenomenon. Seen Sometimes we're individuals in a population are more likely to mate with an individual who's previously made it. So, for example, you'll see this in, uh, certain species like guppies, where, you know, one if a female witnesses a male mate with another female, that female that watched them. No, it sounds kind of creepy, but let's just forget about it for a second. Don't think about it. The female that watched them is going to then be more likely to mate with that male, and that is an example of mate choice copying. Now, parental care is important because it can help improve the chances of raising viable offspring. Males actually will tend to help with parental care in species that require a lot of attention and help feeding. And it seems that the certainty of paternity that is how certain the mail is that those offspring are its offspring seems to have an effect on male parental care. And you'll actually see ah, higher rates of male parental care in species with external fertilization. Because the males, it's thought, have a greater certainty of paternity because they'll go right up to the eggs and fertilize them right there is supposed to internal fertilization, where some other organism could. Some other male could have internally fertilized this organism and, you know it could be its offspring. Just it's harder to know. So here you see an example of some parental care where these little chicks kind of gross looking chicks, to be honest, are going thio, get fed by the parent here. And of course, here you can see a wonderful example off human parental, and that is paternal care. All right, let's flip the page

animals will generally choose where to live based on food and mates. Now, some organisms will actually in their lifetime, move very great distances. This is known as migration. This is a long distance movement of a population, and it's usually associated with seasonal changes. However, organisms will migrate for a variety of reasons, like availability of food sources, differences in climate or for mating purposes. Now we'll actually see three interesting types of migration what we call piloting, which is basically the use of familiar landmarks to find their way. Compass orientation, where the organisms will actually have their movement oriented to a specific direction. And true navigation, which is the ability of animals to find their way as if they were looking at a map as if they had GPS or something. And one example of this is with sea turtles that have a no ability to sense the magnetic field of the earth, and they use that sense of the magnetic field to orient themselves. So you can basically, you know, blind full to sea turtle driving around, taking a bunch of back streets for a while. Throw it in the ocean and it'll still find its way because it has that ability of true navigation. And here you can see a herd of wildebeests migrating, and here you can see some migratory patterns of birds, and hopefully you realize how astounding some of these distances are that these birds will travel. Now. Altruism isn't very interesting type of behavior because it seems counterintuitive. In some ways it's a behavior that actually has a fitness cost to the actor that exhibits it. So the organism that exhibits the behavior receives a fitness cost, meaning there's a detriment to their fitness. And the recipient of this behavior will actually receive a fitness benefits. So why would an organism do this? Ifit's not seemingly in its own self interest. Well, Part of the explanation to this is something known as kin selection, which is an evolutionary strategy that favors the reproductive success of an organism's relatives. And you can see this in organisms like bees, for example. Now Hamilton's rule is a way of looking at altruistic behavior, and it basically says that when certain conditions are met, you're more likely to have an altruistic behavior, and those conditions are that the benefit to the recipient is going to be high. The cost to the actor is gonna be low. And it's also going to factor in something known as coefficient of related nous, which is the average number of genes that are shared between the individuals. So this is represented with the equation that I'm writing out here, and the idea is that the benefit is high enough and the coefficient of relatedness is high enough that it outweighs the cost to the actor. So if you're still wondering why, you know, we would see this type of behavior, why we'd see altruism. This guy Hamilton developed this idea. It's sort of ah, a different way of looking at fitness. And he calls it inclusive fitness. And this is basically, uh, a way of looking at fitness, where you're looking at the evolutionary success of an organism based on the number of offspring it produces, which is pretty standard and how we look at fitness. But it also includes how that individual helps its relatives produce mawr offspring than they otherwise would be able thio on their own. So this is basically a uhh sort of expanded view of fitness that takes into account the Ultra is ultra Ristic behavior that increases the offspring and the survival of the offspring of relatives of the organism. And so it's believed that these behaviors are seen because they might not directly spread on organisms genetics. But because it's happening with relatives, you know, those relatives air going to share a portion of that organism's genes. And so in this, uh, you know, in this sense, the organism is helping to pass on a portion of its own genes by helping its relatives, you know, though it's not directly passing on all of its genes. Now, an interesting idea that has sort of been extrapolated from this thinking is the idea of reciprocal altruism, and this is going to be seen between organisms that are not related. So, uh, you know, no relation there, Uncle Ruckus, no relation. And this is when an actor is going to temporarily reduce its fitness to benefit the recipients under the assumption that the recipient will return the favor some day. And this is, uh, for example, seen in communities of chimpanzees, and it's thought to in part explain some aspect of human behavior and altruism amongst humans. Now, one nice example that I want to leave you with of, uh, you know all of this altruism. All of this thinking is with prairie dogs. Prairie dogs arose. They live in big communities with lots of relatives and prairie dogs exhibit this behavior you see here where they kind of like scream basically to alert their community of the presence of a predator. And I don't know if you could tell, but there's some feathers back here. Prairie dogs have toe watch out for birds of prey, which love to eat them. So this is an example of altruistic behavior. Because by alerting their community by making this noise, these prairie dogs actually draw attention to themselves. So they put themselves at risk of predation at greater risk of predation, in fact, but it helps warn all their brows. And so that means their brows are more likely to survive. And so this is going to help with their inclusive fitness. That's all I have for this one. I'll see you guys next time