Hi. In this lesson, we'll be talking about animal behavior. Now behavior is defined as the actions an 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 going to be interested in the ecological pressures that influence it. Behavioral ecologists are really going to be interested in asking two types of questions. They're going to want to know about what they term 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, you know, biochemically, physiologically develop? Now they're also going to be interested in the why of this. So proximate causation is looking at how this happens 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 of how they affected this organism's survival. Right? So we want to know how these behaviors are going to affect fitness, and how did they evolve in the sense of what pressures encouraged them and discouraged other behaviors. You know, what events led to them being the behaviors that best served this organism.
Now, here you can see an example of 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. 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 can trick a goose by putting something, that they'll think is an egg, it's 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, did this come from dinosaurs, for example? You know, birds did evolve from dinosaurs. Maybe this was a behavior that dinosaurs exhibited, and that's why these geese are showing it. It's like genetically programmed in them from long ago in their ancestors. I mean, I'm just hypothesizing here, but that would sort of be the question of how did this behavior develop. Now, in terms of how does this behavior affect fitness, it should be fairly apparent that if the goose returns the egg to the nest, that egg is going to have a higher chance of survival, meaning more offspring. So, behavior like this will obviously increase fitness because it will lead to a higher rate of offspring reaching viability.
In terms of how did it evolve, what pressures led to this, it could have been a variety of things, but perhaps it was something like the nature of the nests caused eggs to fall out regularly or something as simple and seemingly silly as that. Now, I said that this was an innate behavior, and behaviors actually run on a spectrum from learned to innate. And innate behaviors are genetically programmed. They are going to just happen automatically, though it should be noted that some innate behaviors will require an organism to learn aspects of it, or fine-tune aspects of it, and that's why it's better to think of behaviors as existing on a spectrum from learned to innate rather than existing in these two clearly defined categories. Now a great example of an innate behavior is 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 cue, which we'll 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, a fixed action pattern that is elicited by a sign stimulus is going to be something like the behavior of the male stickleback fish.
Now, these fish will, 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 of attacking anything they see that has a red belly. And the red belly, we know to be the sign stimulus because you can put an 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 doesn't look anything like a fish, but has that redness to it, and the male stickleback will attack it. So that is an example of a sign stimulus, this red belly, and it's going to elicit that fixed action pattern of the fish attacking it. With that, let's go ahead and flip the page.