Archived lectures from undergraduate course on animal behavior given at Arizona State University by Ted Pavlic
In this lecture, we discuss the upcoming two-stage final exam and review important topics from each of the previous units. Topic highlights:
This lecture introduces students to use of behavioral ecology to study social behavior (and thereby opens the door to the field of sociobiology, the topic of a follow-on course). The lecture starts with a discussion of conspicuous social behaviors seen in collective motion, as in starling murmurations, and discusses how the "selfish herd" hypothesis provides an explanation for these patterns based entirely on benefits to individuals (and not benefits to the group). This discussion motivates a description of the grid of social behaviors that mix costs and benefits to actors with costs and benefits to recipients, including altruism, spite, by-product mutualism, and selfishness. The bottom half of the lecture focuses on introducing inclusive fitness theory (kin selection) as an explanatory framework for understanding some forms of (apparent) altruism, where an individual pays an appreciable cost to perform an action that provides an appreciable benefit to a relative. This allows for introducing the Prisoner's Dilemma from game theory and using it to derive Hamilton's rule, which is a theoretical framework for predicting when benefits to relatives are strong enough to outweigh the costs to the individuals doing them. We then close by applying Hamilton's rule to a parental–investment problem considered by Trivers (first discussed in a prior lecture on parental care) that ends up predicting that offspring may evolve behaviors that lead to over-investment by parents relative to the investment strategy that is best for the reproductive success of the parents.
Topic highlights:
Important terms: murmuration, selfish herd, domain of danger (or “Voronoi cell”), social exploitation, positive externalities, public good, by-product mutualism, negative externalities, common-pool resources (or open-access goods), Tragedy of the Commons, selfishness, altruism (or cooperation), spite (or altruistic punishment), Prisoner’s Dilemma, inclusive fitness theory (or kin selection), relatedness, direct fitness, indirect fitness, inclusive fitness, Hamilton’s rule, Generalized Hamilton’s rule
In this lecture, we return to the notion that different amounts of physiological reproductive investment can lead to different behaviors. However, whereas we focused on mating behaviors and sexual selection in the previous lecture, we pivot to parental care behaviors here. Parental behavior involves interactions with a wider range of individuals – from multiple offspring (both current and future) as well as other individuals that share in parenting or the fitness consequences of parenting – as well as many more degrees of freedom of behavior. Life history theory, which we introduce in this lecture, provides a framework for understanding consistent behavioral patterns that tend to emerge from different environments. After discussing life history theory, highlight different forms parental behavior and the kinds of opportunities and conflicts that can emerge from them. After discussing topics surrounding infanticide in biparental care, we close with an introduction to classical theories in parent–offspring conflict.
Topic highlights:
Important terms: anisogamous species, spermatophore, nuptial gifts, Syngnathidae, brood pouch, breeding sail, parental care, parental investment, life history traits, life history strategy, life history theory, 𝑟-selected, 𝐾-selected, sibling conflict, sibling rivalry, insurance egg hypothesis, parent–offspring recognition, external fertilization, egg guarding, mouth brooding, fry, alloparental care, uniparental care, biparental care, maternal care, paternal care, altricial young, joey, precocial young, sexual conflict, infanticide, concealed ovulation, The Bruce effect, parent–offspring conflict, begging, weaning
In this lecture, we discuss sexual reproduction and how asymmetries in investment can lead to asymmetries in mating behavior among the sexes. We open the lecture with preliminaries and definitions related to the biological description of sexual behavior. We then introduce Bateman's principle and the various downstream predictions of it related to animal behavior. We then pivot to cases which may appear to contradict Bateman's principle. We then close with a discussion of the likely reason why sex evolved and the different functions that mate choice has to provide.
Topic highlights:
Important terms: sex, meiosis, mating/sexual reproduction, physiological and anatomical differences correlated with the production of different types of gamete, including, primary sexual characteristics, secondary sexual characteristics, somatic cells, gametic cells (or gametes), diploid, haploid (or sometimes monoploid), sperm (or spermatozoa), eggs, “cost of meiosis”, haplodiploid sex-determination system, Bateman’s principle, polygyny, monogamy, polyandry, sperm competition, spermatophore, nuptial gifts, Syngnathidae, brood pouch, breeding sail, Red Queen Hypothesis, anisogamous species, hermaphrodite, protandrous hermaphrodites, protogynous hermaphrodites, isogamous species
In this lecture, we discuss fundamentals of self defense from predators. We start with an introduction to mimicry, which allows prey with significant defenses to converge on signals that are easier for larger predators. We also describe prey that do not have significant defenses but can deceptively mimic those organisms that do in order to make themselves appear to be less palatable than they are. This gives us an opportunity to discuss the how mimicry can lead to mimicry complexes embedded in ecological communities. We also discuss other forms of crypsis, including camouflage and hiding, and strategies for providing more time to evade a predator, such as startle behavior and vigilance. We close with an exploration of agonism more broadly and how individuals in agonistic interactions may sometimes choose to fight and other times choose to flee. We use the Hawk–Dove game from game theory to illustrate the balance in such choices and explore a special case of predator–prey oscillations related to a similar negative frequency-dependent selection phenomenon.
Topic highlights:
Important terms: mimicry, mimic, model, Müllerian mimicry, Batesian mimicry, mimicry complex, aposematism/aposematic signaling, crypsis, camouflage (a form of crypsis), startle behavior, vigilance, agonistic behavior, correlated asymmetries, uncorrelated asymmetries, negative frequency-dependent selection, Hawk–Dove game ("game of chicken"), pure Nash equilibrium, mixed Nash equilibrium, co-evolutionary arms race, three different categories of self-defense strategies
In this lecture, we pivot from thinking about optimal group size when animals have positive externalities to using the same logic to better understand how animals distribute themselves within a habitat. We introduce interference and scramble competition as mechanisms that couple animal decision making, and then we introduce the Ideal Free Distribution (IFD) as a concept that can predict the likely location of animals under these competitive pressures. The IFD is a natural extension of the matching law from psychology. There can be variations of the IFD due to differences in competitive ability (which are modeled by the ideal despotic distribution, IDD) as well as due to non-foraging-related conspecific attraction (which can lead to colony life). The IFD does give us an opportunity to introduce the Nash equilibrium, which we then use to discuss another important model in social foraging, the stag hunt game. Closing with the stag hunt game lets us introduce concepts such as social efficiency, payoff and risk dominance, and coordination and assurance games.
Topic highlights:
Important terms: habitat choice/selection, interference competition, scramble competition, ideal free distribution (IFD), matching law (from psychology), ideal despotic distribution (IDD), conspecific attraction, colony, Nash equilibrium, stag hunt game, socially efficient, payoff dominant, risk dominant, coordination game, assurance game
In this lecture, we introduce social foraging as an opportunity for exploitation by conspecifics to either: (a) exploit positive externalities from the foraging behaviors of others, or (b) make foraging choices that reduce the benefit to others around them (imposing negative externalities). We discuss how these pressures complicate understanding the foraging group sizes observed in nature – such as densities of socially foraging bats and sizes of wolf packs. In particular, we introduce the tragedy of the commons (and open-access/common-pool resources) as a conceptual framework for understanding group sizes. We then pivot to focusing on within a group, how do individuals decide whether they should search for food or pay attention to others who are searching for food (and then parasitize the discovered food locations). This gives us an opportunity to use basic game theory to make predictions about behaviorally stable strategies (i.e., strategies that can change dynamically but will have consistent outputs in consistent contexts).
Topic highlights:
Important terms: positive externality, negative externality, open-access resource/common-pool resource, tragedy of the commons, “G star” (intake-maximizing group size), “G hat” (open-access equilibrium group size), finder’s advantage, Stable Equilibrium Frequency (SEF), Behaviorally Stable Strategy (BSS)
In this lecture, we continue using an opportunity cost perspective to predict optimal foraging behavior of predators. We pivot from a review of the marginal value theorem (and the patch model for patch residence times) from the last lecture to an introduction of the prey model of optimal diet choice. This allows us to introduce the profitability-ranking solution of the prey model. After exploring experimental evidence for the validity of this solution, we turn attention to how physiological constraints and shift animals to other diet portfolios. We give examples from sodium limitation in moose, water limitation in spiders, and ballast constraints in shorebirds. Overall, we come to the conclusion that there are many drivers of foraging behavior, and behavioral ecologists choose different model organisms specially to allow for focusing on the effect of each one.
Topic highlights:
Important terms: patch, patch residence time, diet choice/prey choice, marginal returns/gain, diminishing marginal returns, opportunity cost, optimal foraging theory, rate maximization, Marginal Value Theorem (MVT), The Prey Model, diet choice, zero–one rule, profitability, profitability ranking, gizzard, partial preferences
In this lecture, we focus on adaptations to foraging that are shaped by opportunity cost and risk of starvation. Before getting to that, we open with a short discussion of different trophic strategies and the time pressures on each of them. After discussing the ways in which sit-and-wait/ambush predators can use lures and special placement to alter the rate at which they encounter prey, we then switch our focus to mobile predators that make decisions about how long to stay in patches of prey items that they encounter in a heterogeneous, clumpy environment (i.e., how to balance instantaneous rewards of local exploitation with the costs of lost opportunity from continuing to search more broadly). This discussion lets us introduce the Marginal Value Theorem (MVT) of optimal foraging theory and interpret it as a biological version of the equimarginal principles used in economic analysis of consumer behavior. We then shift to thinking not about opportunity cost so much as the risk of starvation for foragers that must reach a minimum threshold for energetic gain by a certain time in order to survive. This lets us introduce risk-sensitive foragers (including risk-prone and risk-averse foragers), the notion of a "stretch goal," and the notion of "bet hedging."
Topic highlights:
Important terms: predator saturation/swamping/starvation, trophic strategies, carnivory, hematophagy, herbivory, frugivory, folivory, omnivory, scavenging, carrion, predation, sit-and-wait/ambush predators, pursuit predation, parasitism, parasitoid, parasitoid oviposition, micro-predator, kleptoparasitism, active hunter/predator, foraging, central-place forager, handling time, opportunity cost, optimal foraging theory (OFT), patch, marginal returns, patch residence time, marginal value theorem (MVT), equimarginal principle, optimal diving models, risk-sensitive foraging, risk prone/risk averse, stretch goal, bet hedging
In this lecture, we introduce the foundations and key motivations behind the study of foraging behavior, including some of the foundations of (optimal) foraging theory. We start by highlighting how the key difference between plants and animals comes down to energy acquisition and movement and thereby establish foraging (the search for food) as a key driver of movement behavior in "animated" animals (as opposed to "planted" plants that do not have to search for their source of energy but do have to compete for access to it). We note that movement is also needed for other contributors to reproductive success, such as fighting, fleeing, and reproduction, and so foraging strategies must balance the direct gains of those strategies against the opportunity costs of other things that could be done with that time. Toward that end, we introduce fitness proxies and give a rationale for why energetic rate of gain is a common proxy used that encapsulates the opportunity cost of other activities. We then discuss motivational examples from the study of quail foraging behavior and nutrient-constrained foraging in sloths.
Topic highlights:
Important terms: autotroph (primary producer), heterotroph (consumer), foraging, opportunity cost, fitness proxy/fitness surrogate/currency, functional response (type-I, type-II, type-III), Holling’s disc equation, handling time, instantaneous rate of capture of each prey
In this lecture, we continue to discuss navigation in the context of homing and migration and then move on to discuss dispersal movement. We use examples from a few key model organisms (such as Cataglyphis ants, homing pigeons, wolf spiders, and monarch butterflies) to highlight different ways that odometry can be used to update idiothetic information used in navigation as well as different external cues that can serve as allothetic information for navigation. We transition from a detailed discussion of homing to an overview of key topics in migration (and navigational tools used there). We then close with a discussion of the function and mechanisms of dispersal.
Topic highlights:
Important terms: navigation, homing, Cataglyphis ants, homing pigeons, path integration, home vector, idiothetic information, odometer (and odometry), step counting, visual odometry (optical flow), allothetic information, landmarks, displacement experiments, snapshot orientation, magnetic maps, magnetic compass, celestial cues (and the sun compass), cognitive map, migration, stopover, dispersal
In this lecture, we introduce key concepts in the study of animal movement related to movement during search and navigation. We start with a motivating examples from fiddler crabs -- homing and path integration as well as search (both for food and for displaced burrows). Ending those examples with search allowed us to discuss other more general search-related topics, such as kinesis, taxis, and triangulation. We then close coming back to path integration, but this time in Cataglyphis desert ants and their step-counting odometer.
Before starting into movement and navigation in this lecture, we discuss the expectations for the final team project.
Topic highlights:
Important terms: navigation, homing, path integration, search, Lévy flight/walk, orientation, directional movements, random movements. odor-plume tracking, kinesis (plural kineses), klinokinesis, orthokinesis, taxis (plural taxes), klinotaxis, tropotaxis, telotaxis, anemo-, chemo-, geo-, magneto-, photo-, skoto-, triangulation, sequential triangulation, simultaneous triangulation, stereopsis, allothetic information, idiothetic information, odometer (and odometry)
In this lecture, we discuss the upcoming two-stage midterm exam and review important topics from each of the previous units.
Topic highlights:
In this lecture, we discuss more complex topics in communication, such as: the quantification of information in multi-modal, multi-channel signals, the shaping of signal characteristics by sexual selection, and the role of cost in the maintenance of honest signals (both for intraspecies communication and interspecies communiction). We also discuss how different methods of communication exploitation that are categorized under deceitful or "dishonest" signaling (both in intraspecific and interspecific interactions).
Topic highlights:
Important terms: encoding, code, bit, information theory, honest signal, handicap principle, bower, extended phenotype, dishonest/deceitful signal, supernormal stimulus, brood parasitism, cleaner fish
UNFORTUNATELY, THERE WAS SOME PROBLEM WITH THE RECORDING SETUP IN THE ROOM. IRONICALLY, THE AUDIO DOES NOT SEEM TO BE WORKABLE IN THIS VIDEO ABOUT ACOUSTIC COMMUNICATION.
In this lecture, we discuss the major modes of communication and spend some time discussing how animals use these different modalities to signal each other. This lecture focuses on a variety of communication mechanisms across the modalities and how they might have been co-opted from existing mechanisms that were adapted for other functions. After discussing tactile, chemical, acoustic, visual, and electric communication, we close with a brief discussion of multi-modal signals.
Topic highlights:
Important terms: communication mode/modality, antennae, semiochemical, pheromone, allomone, kairomone, synomone, volatile pheromones, headspace, contact/non-volatile pheromones, cuticular hydrocarbon (CHC), primer, releaser, stridulation, frequency, complex sound waves are viewed as sums of many different frequencies of simple oscillating sound waves, amplitude, tymbal, multi-modal communication
In this lecture, we will introduce basic theories of communication and the evolution of communication in animal behavior. We focus on the relationship between communications and signals as well as how signals can evolve from cues and then be further elaborated with stereotypy and redundancy (possibly leading to multi-modal communication). This also gives an opportunity to introduce autocommunication, public information, and eavesdropping.
Topic highlights:
Important terms: communication, signal, cue, ritualization, stereotypy, redundancy, autocommunication, co-option, exaptation, noise, semaphore/sempahoring, public information, eavesdropping, concealment, private information, multimodal communication
In this lecture, we address perspectives on animal behavior that explain animal motivation by use of latent, unobservable structures. We start by exploring drive theory and the hydraulic models of drive from early ethology and use that to pivot to an introduction of cognition and the separation of the physical "brain" and the metaphorical "mind." Such a "mind" can do things like: being aware of itself in context of a larger world, be aware of the mind and motivation of others and use this information to drive its own behavior, predict future events based on past experience, and so on. We present cognition as an unobservable mechanism behind behavior, but we also discuss the risks of this approach to confounding proximate and ultimate explanations of behavior as well as the risks of false conclusions about animal intelligence due to a lack of ecological relevance in some standard tests of cognition and intelligence. Ultimately, we recognize that despite the risks, cognitive models can be formative in the process of forming research questions, and they provide one way to incorporate animal motivation into hypotheses about behavior (which would otherwise be difficult to do based on what can be outwardly observed alone).
Topic highlights:
Important terms: drive theory, displacement behavior, redirected behavior, self-directed behavior, stereotyped behaviors, cognition, theory of mind, time–place learning, gaze following, cache thievery, the mirror test, motivation
In this lecture, we use the foundations of learning from the previous lecture as a lens to provide perspective on several different forms of complex learning observed in animals.
Topic highlights:
Important terms: trial-and-error learning, taste-aversion learning, cache retrieval, social learning, observational learning, scatter hoarding, larder hoarding, reforaging, searching-by-rule, pilferage, tandem running
NOTE: UNFORTUNATELY, THE AUDIO CUTS OUT AROUND 36:45.
In this lecture, we provide foundations for discussing an important form of plasticity in animal behavior – learning. The response an animal has to its environment can be innate, or it can be modified by experience with its environment, resulting either in short-term changes (short-term learning) or long-term changes (long-term learning) with the possibility of very long-lasting changes (long-lasting learning). We discuss the different benefits and costs of these different forms of learning, which will also involve a brief description of the neural mechanisms underlying learning in animals. We then move to methods of measuring learning in behavioral experiments as well as categorizations for different forms of learning. This will allow us to introduce both non-associative learning (habituation and sensitization) and various forms of associative learning.
Topic highlights:
Important terms: learning, forgetting, extinction, learning/forgetting/extinction curve, innate behaviors, short-term/working memory, long-term memory, long-lasting memory, periodic reinforcement, memory consolidation, stimulus, response, imprinting, habituation, sensory adaptation, sensitization, conditioning/associative learning, operant conditioning, prepared/unprepared/contraprepared, reinforcement (positive and negative), punishment (positive and negative), classical conditioning, unconditioned/conditioned stimulus/response
In this lecture, we pivot from describing behavioral methods for disentangling nature (genetics) from environment (nurture) and turn toward more quantitative approaches to assessing heritability and the contribution of genes to phenotype. First, we return to the topic of "heritability" as a measure of the contribution of genetic variance to observed phenotypic variance and define two different forms of heritability – broad-sense heritability (which includes non-additive genetic effects) and narrow-sense heritability (which only includes additive genetic effects). We show how to use parent–offspring phenotypic analyses to measure narrow-sense heritability ("h squared"). As heritability will vary in a population if the corresponding trait is under selection, we then discuss how to use genetic analyses to infer whether a population is at equilibrium or currently in the process of evolving through selection or by other means. This gives us an opportunity to discuss the "Hardy–Weinberg equilibrium" and discuss some practical ways to use it. We then conclude with an introduction to QTL mapping and GWAS for understanding which combinations of genes contribute to a particular behavior (and how).
Topic highlights:
Important terms: heritability, narrow-sense heritability, broad-sense heritability, Hardy–Weinberg equilibrium, quantitative traits, quantitative trait loci (QTL), QTL mapping, genetic markers, single-nucleotide polymorphisms (SNPs), linkage map, genome-wide association study (GWAS, GWA study)
In this lecture, we continue our discussion of the combined role of genetics and the environment in the expression of a phenotype. We start by focusing on concepts from molecular genetics related to testing for the role of a single "candidate gene" using techniques like RNA knockdown. We then consider the role of epigenetics in the expression of a phenotype and discuss DNA methylation, cell differentiation, behavioral epigenetics, and genomic imprinting. Ultimately, this leads us back to seeking methodological ways to identify when a behavior has a strong genetic or environmental basis (before we look into which genes are playing the largest role). So, we introduce cross fostering, twin studies, and common gardening, which are three different ways to test whether a behavior is being determined more by the environment or by the genes.
Topic highlights:
Important terms: molecular genetics, candidate gene" RNA knockout, epigenetics, DNA methylation, behavioral epigenetics, genomic imprinting, cross fostering, twin studies, common gardening/transplant experiments
In this lecture, we cover foundational topics in modern synthesis of behavioral genetics. The lecture starts with the nature-versus-nurture debate and its historical roots in tensions between American psychologists and European ethologists (fueled in part by geopolitical contexts at the time), including a brief mention of the emergence of EO Wilson's "Sociobology" and the response to it. Ultimately, we cover the more modern, integrative, "nature-via-nurture" perspective where phenotype reflects effects of both genes (potentially many genes) and their interaction with the environment ("GxE"), and biologists are interested in understanding the relative contributes of both (e.g., with "heredity" quantifying the relative contribution of genotypic variation to phenotypic variation in a population). We then discuss different historical fields that have contributed to the modern synthesis and examples of what they have contributed. That gives us an opportunity to discuss phenomena identified in evolutionary biology that help to explain the counterintuitive observation that, for reasons unrelated to genetic drift, many traits that have an apparent fitness cost are still maintained (or at least not purged) in a population. We close looking forward to a unit on behavioral genetics that will introduce methods that behavioral ecologists use to try to separate genetic and environmental effects as well as quantitative tools for better understanding which genes contribute in complex ways to any particular phenotype/trait.
Topic highlights:
Important terms: G by E (GxE), G by E to P (GxE->P), GxGxE, epistasis, ecotype, gene, allele, genotype, character, trait, phenotype, expression, genotypic variance, phenotypic variance, heredity, quantitative trait, artificial selection/breeding, phylogeny, cladogram, correlated characteristics, phenotypic inertia, disruptive selection, handicap principle
In this lecture, we consider the different historical approaches that have led up to modern behavioral ecology, including ethology and behaviorism. This gives us an opportunity to discuss von Uexküll's "umwelt" and give various examples of animals whose sensory and perceptual experience is notably different than the experience of a human. This sets us up to discuss how important it is to consider the physiological mechanisms and constraints that can limit what kinds of behaviors are able to evolve, and we use ring dove mating as an example of this. We close by looking ahead to the next unit on behavioral genetics and discuss how the four different mechanisms of evolution (natural selection, genetic drift, mutation, and migration) also can shape the patterns of behaviors that can evolve. Overall, this lecture helps to draw boundaries around what is the field of behavioral ecology while also establishing that those boundaries are necessarily porous and permeable and must both be influenced by and influence surrounding fields from physiology and evolution.
Topic highlights:
Important terms: behaviorism, ethology, umwelt, genetic drift, mutation, migration, natural selection
In this lecture, we review the scientific foundations of animal behavior. We define a causal question, a hypothesis, a theory, an experiment, and a prediction and how they all relate to each other. We also cover Tinbergen's four questions (the four different levels of analysis in biology and behavioral ecology). This is all done in the context of talking about the cephalopod eye (with an octopus and a cuttlefish example) and its comparison to the vertebrate/human eye. We end with a short discussion of how to define "behavior" most generally and with the most utility.
Topic highlights:
Important terms: causal question, hypothesis, prediction, experiment, theory, Tinbergen's four questions (or causes), function/adaptation/utility, phylogeny/evolution, ontogeny/development, mechanism, chronogram
This lecture introduces BIO 331 (Animal Behavior) and its policies. Most of the lecture covers administrative and structural aspects of the course, but in the middle there is an examination of the "stotting" behavior that occurs in many ungulates where students propose different hypotheses for the phenomenon. The stotting example is meant to motivate the kinds of things that will go on in the course.
Topic highlights:
