Behavioral Ecology Exam 1

What's the difference between an ethogram, a time budget, and stereotypic behavior?

Ethogram:

• A catalog of an animal's behaviors, each with a clear operational definition.

• Purpose: Observers code behavior objectively and consistently.

Time Budget:

• The proportion of time an individual or group spends on each activity (e.g., foraging, resting, grooming).

• Usually built from scan sampling data.

• Purpose: Shows how animals divide their time and energy across competing needs.

Stereotypic Behavior:

• Repetitive, unvarying, apparently functionless behaviors (e.g., pacing, crib-biting, head-weaving).

• Cause: Chronic stress, confinement, barren environments, or frustration of natural motivated behaviors.

• Often used as an indicator of poor welfare. See Rees (2009) on elephants.

Memory hook: Ethogram = the dictionary. Time budget = the percentages. Stereotypy = the red flag.

What are stereotypic behaviors, and what did Rees (2009) find about feeding and stereotypy in captive Asian elephants?

• Stereotypic behavior: Repetitive, invariant, functionless actions (e.g., swaying, weaving, pacing), linked to confinement, frustration, and restricted natural behaviors.

• Rees (2009):

  • Method: Scan sampling of captive Asian elephants every 5 minutes.

  • Finding: Stereotypy was strongly negatively correlated with feeding time. More time eating went with less stereotypy.

• Management implication: Replace predictable, clumped feedings with small amounts at unpredictable times, such as through automated feeders, to restore natural foraging time budgets.

• Exam punchline: Enrichment that restores natural foraging time is expected to reduce stereotypic behavior.

• Watch out: The core finding is a correlation, so it doesn't by itself prove that feeding time causes the drop.

Define the null and alternative hypotheses, directional vs. non-directional hypotheses, and how to interpret negative results.

• Null hypothesis (H₀): Observed patterns are due to chance alone, with no real effect or difference between treatments.

• Alternative hypothesis (H_A): The tested factor has a real effect.

  • Directional: predicts a specific direction (e.g., more food → more territorial defense). This uses a one-tailed test.

  • Non-directional: predicts an effect in either direction. This uses a two-tailed test.

• Negative results: The data don't reach statistical significance (usually p > 0.05).

  • Conclusion: Fail to reject H₀. This never "proves" H₀ true, only that the evidence for an effect is insufficient.

  • They're still valuable, since leaving them unpublished causes publication bias.

Scientific Theory vs. Anthropomorphism

• Scientific Theory:

  • A broad, explanatory framework that has been repeatedly tested across independent studies and diverse empirical systems, receiving extensive empirical support without being falsified.

  • Contrasted with "Hypothesis": A hypothesis is a specific, testable prediction for a single question; a theory is an overarching, heavily corroborated model that unifies multiple lines of evidence.

• Anthropomorphism:

  • The practice of projecting human emotions, conscious motives, feelings, or cognitive intentions onto non-human animals.

  • Why It Undermines Science: Yields subjective, untestable interpretations of behavior that cannot be empirically measured, masking the true proximate and ultimate evolutionary drivers.

Correlation vs Causality & Rohr et al. (2008)

• Core Principle: Correlation does not equal causation. Two variables can look related because both are tied to a third factor, here time, rather than because one causes the other.

• Prior Claim (Pounds et al. 2006): Climate warming caused mass die-offs of Atelopus harlequin toads by creating conditions that favored outbreaks of chytrid fungus (Batrachochytrium dendrobatidis).

• Rohr et al. 2008 Reanalysis (Why It Was a Misleading Correlation):

  • The correlation was confounded by time:

    1. The fungus was spreading across the landscape like a wave, reaching new areas year by year.

    2. Over those same years, temperatures were also rising.

  • Key evidence: Once the time trend was accounted for, the temperature link didn't hold up. The timing of declines fit the spread of the fungus better than it fit warming.

• Core Takeaway: Two variables rising together over time don't necessarily cause each other. The evidence pointed to a spreading pathogen as the main driver, not warming.

What does the Kokko & Morrell (2005) mate-guarding model predict about when males should guard, and which males guard most?

Optimality model: Males should guard only when the paternity protected outweighs the costs of time, energy, and missed extra-pair matings.

Guarding vs. female infidelity (hump-shaped curve):

• Always faithful: Paternity is already secure, so guarding is wasted effort.

• Always unfaithful: Guarding can't prevent enough infidelity to be worth it.

• Intermediate infidelity: Guarding actually changes paternity, so it peaks here.

Guarding vs. male attractiveness:

• Unattractive males guard most. They have few extra-pair opportunities, so guarding costs them little (low opportunity cost), and their social mate is their main source of offspring.

• Attractive males guard less. Time spent guarding means missed extra-pair matings, so seeking other females pays off more.

Memory hook: Guard when it can make a difference (middle infidelity) and when you have little else to lose (unattractive male).

Horowitz (2009): The "Guilty Look" in Dogs & Anthropomorphism

• Question: Does a dog's "guilty look" reflect actual guilt, or is that an anthropomorphic interpretation?

• Design: Owners told dogs not to eat a treat and left. The experimenter controlled whether the dog actually ate it and what the owner was told (correctly informed or misinformed).

• Findings:

  • The guilty look appeared whether or not the dog ate the treat.

  • It was strongest when owners scolded the dog, especially when the dog had actually obeyed.

• Takeaway: The look responds to owner cues (scolding tone and posture), likely as an appeasement display, not as evidence of guilt.

• Watch out: This doesn't prove dogs can't feel guilt. It shows the look isn't reliable evidence of it, so intuitive interpretations need testing.

What are Darwin's 3 conditions for natural selection, and what happens when all are met?

• The 3 conditions:

  1. Variation: Individuals differ in a trait. This is the raw material for selection.

  2. Heritability: Those differences are at least partly genetic and passed to offspring (h² > 0).

  3. Differential fitness: Individuals with different trait values differ consistently in survival and reproduction.

• Outcome: When all 3 are met, advantageous traits increase in frequency over generations (adaptive evolution).

• Exam trap: Without heritability, selection can still happen within a generation (who survives), but the population won't evolve. Purely environmental differences aren't passed on.

What are the 5 causes of behavioral variation in a population? Which generate it, and which maintain it?

How variation is generated (1–3):

1. Genetic differences: Different alleles influence behavior (e.g., rover vs. sitter alleles of the foraging gene).

2. Environmental differences: Different conditions trigger different behaviors through phenotypic plasticity (e.g., predator cues, diet).

3. Learning and experience: Individuals change behavior based on experience (e.g., naive bumblebees learning to handle flowers).

Why selection doesn't eliminate it (4–5):

4. Neutral variation: Variants have equal fitness (W₁ = W₂), so selection doesn't favor either (e.g., screech owls dispersing in random directions).

5. Negative frequency-dependent selection: A morph's fitness drops as it becomes more common, so rare morphs have the advantage and both persist (e.g., birds attacking the common salamander morph).

How did Dingemanse et al. show that exploratory behavior in great tits is heritable? Name both methods.

• Question: Does exploratory personality (fast/bold vs. slow/cautious) have a genetic basis (h² > 0)?

• Setup: Wild great tits (Parus major) were placed in a novel room with artificial trees, and their movements (hops and flights) were scored as an exploration measure.

• Two tests:

  • Parent-offspring regression: a positive slope, so fast-exploring parents tended to have fast-exploring offspring. The slope estimates h².

  • Artificial selection: breeding fast × fast and slow × slow made the lines clearly diverge within about 4 generations.

• Takeaway: Exploration is partly heritable. It has an additive genetic basis and responds quickly to selection, but the environment still matters.

Directional Selection & Miles (2004): Tree Lizard Locomotion

Directional selection: individuals with an extreme trait value at one end of the spectrum have the highest fitness.

Miles (2004), juvenile ornate tree lizards:

• Methods: tested locomotor performance on a 2 m raceway, measured body size and mass, marked and released the lizards, and tracked survival for 6 months.

• Result: locomotor performance depends on stride length.

• Conclusion: strong directional selection on limb length in juveniles enhances survivorship.

Punchline: Longer limbs → longer strides → better performance → better survival. Selection favors one extreme.

Disruptive vs. stabilizing selection: what does each favor, and how does it change the distribution?

Disruptive selection

• Favors: both extremes. Individuals at either end of the spectrum have the highest fitness.

• Distribution: the middle gets removed, and the population splits toward two peaks.

Stabilizing selection

• Favors: intermediate trait values.

• Distribution: the extremes get removed, and the population narrows around the middle.

• Example: your slides give only the definition and graph, with no featured study. Know the definition and the shape.

Punchline: Disruptive = extremes win, the middle loses, and the curve splits (spadefoot tadpoles). Stabilizing = the middle wins, extremes lose, and the curve narrows.

Frequency-Dependent Selection (Fitzpatrick 2009)

• Negative Frequency-Dependent Selection: Fitness is inversely related to a phenotype's frequency, so the rarer morph has higher fitness.

  • Result: Maintains a stable polymorphism BECAUSE THEY SWING BACK AND FORTH (both morphs persist).

• Fitzpatrick et al. (2009), Clay Model Salamanders:

  • System: Clay models of striped vs. unstriped red-backed salamanders, with the common morph varied between plots.

  • Finding: Birds attacked whichever morph was common more often.

  • Likely mechanism: Predators form a search image for the common form, so the rare morph escapes attack. As a morph becomes common, it loses that advantage, which keeps both morphs in the population.

Individual Selection vs Lemming Suicide Fallacy

• The Core Evolutionary Rule:

  • Natural selection acts on individual differential reproductive success, not for the "good of the group" or "survival of the species."

  • Self-sacrificing alleles cannot spread because non-sacrificing "cheaters" survive, reproduce, and outcompete them.

• The Fallacy (Wynne-Edwards / Group Selection):

  • Myth: Lemmings commit mass suicide by jumping off cliffs to reduce population density and save the species from food starvation.

• The Reality (Individual Selection):

  • High-density dispersal: When population density explodes, local food depletes and competition skyrockets.

  • Individuals migrate to find food and survive for themselves.

  • Drownings occur accidentally when attempting to cross large water barriers (rivers/fjords), not as intentional suicide.

Kin Selection, Inclusive Fitness & Multilevel Selection

Kin selection: individuals can increase their fitness by helping close relatives.

Inclusive fitness: individual fitness + fitness gained by helping close relatives.

Multilevel selection: selection on both groups and individuals.

• A > B: within a group, selfish (A) individuals beat altruists (B)

• BB > AA: between groups, altruistic groups beat selfish groups

Related terms:

• Individual selection: natural selection at the level of individuals

• Group selection: selection favoring some groups over others of the same species

Punchline: Cooperation can evolve by helping relatives (kin selection → inclusive fitness) or because cooperative groups beat selfish groups, even though selfish individuals win within a group.

Optimality theory vs. ESS: what's the difference?

Cost-benefit approach (optimality)

• Key question: What's the best trait when your payoff depends only on the environment?

• Assumption: selection tends to favor the trait with the highest fitness. It doesn't always reach it, because of constraints and trade-offs.

• Optimal trait value: the trait value with the highest fitness in a given environment.

• Method: compare costs and benefits and pick the highest net benefit (benefit − cost).

• Example: crows drop whelks from about 5 m, the height that breaks shells with the least total flying.

Game theory / ESS

• Key question: What's the best behavior when your payoff depends on what others do?

• Maynard Smith & Price (1973) first applied game theory, borrowed from economics, to animal behavior.

• Animals are players; strategies are behaviors.

• Frequency-dependent: a strategy's payoff depends on how common each strategy is.

• ESS: a strategy that, once most of the population uses it, can't be invaded by any rare alternative. It's stable, but not necessarily best for the group.

• Example (Hawk-Dove): in a population of all Doves, Hawks win, so Hawks spread. In a population of all Hawks, Doves avoid injury, so Doves spread. The population often settles at a stable mix, which is the ESS.

Punchline

• Payoff depends only on the environment → cost-benefit → optimal trait.

• Payoff depends on others → game theory → ESS, a strategy that once common can't be invaded.

Sexual Selection & Hill (1990, 1991): Carotenoid Plumage in House Finches

• Definition of Sexual Selection:

  • A form of natural selection acting directly on traits that increase mating success (rather than survival), frequently driving sexual dimorphism.

• The Hill Experiment (House Finches — Haemorhous mexicanus):

  • Observation: Male finches display variable red/yellow plumage derived entirely from dietary carotenoids.

  • Manipulation: Experimentally altered male breast plumage colors using non-toxic dyes to control for potential confounding behaviors.

  • Results: Females showed a strong, active mate preference for males with the brightest red coloration.

• Evolutionary Takeaway (Honest Indicator):

  • Proves bright red plumage is maintained via female choice (intersexual selection).

  • Carotenoid coloration serves as an honest signal of quality, reflecting nutritional condition, foraging efficiency, and parasite resistance.

Tinbergen's 4 Questions: Proximate Explanations (HOW)

Definition: Proximate explanations focus on the immediate causes of behavior.

Q1. Mechanism: What mechanism caused the behavior?
e.g., new dendritic spines in mice; Gp-9 gene in fire ants

Q2. Development: How does the behavior develop?
e.g., closed- vs. open-ended song learning; imprinting

Punchline: Proximate = how a behavior happens, through its mechanism and development.

What are Tinbergen's two ultimate ("why") questions, and how do they differ?

Definition: Ultimate explanations focus on the evolutionary or fitness consequences of a behavior.

Q3. Function: What is the function of the behavior? How does it affect survival, reproduction, or fitness?
e.g., longer limbs improve juvenile lizard survival (Miles 2004)

Q4. Evolution: How did the behavior evolve?
e.g., mapping burrowing onto the mouse phylogeny (Weber & Hoekstra 2009)

Punchline: Ultimate = why a behavior exists, through its fitness function and its evolutionary history.

Observational Sampling: Focal vs Scan

• Focal Animal Sampling (one individual, continuous):

  • How: Pick one individual (ideally at random) and record everything it does for a set block, such as 15 minutes.

  • Best for: Exact durations, frequencies, sequences, and rare behaviors.

  • Trade-off: Very detailed, but covers few animals and misses what the rest of the group is doing.

• Scan Sampling (whole group, snapshots):

  • How: At fixed intervals, such as every 30 seconds, sweep the group and record what each visible individual is doing at that instant.

  • Best for: Time budgets, like the percentage of time spent feeding vs. resting vs. traveling.

  • Trade-off: Covers many animals, but misses brief or rare behaviors between scans and is biased toward conspicuous behaviors and easily seen animals.

• Exam punchline: Focal gives depth on one animal, scan gives breadth across the group. Durations and sequences point to focal; proportions of time point to scan.

The Comparative Method & Weber & Hoekstra (2009): Deer Mouse Burrows

Comparative method: linking phylogenies with differences between species to understand how behaviors evolved.

• Ancestral (plesiomorphic): present in the common ancestor

• Derived (apomorphic): in more recent species, not in the common ancestor

• Sister species: more closely related to each other than to any other species

Weber & Hoekstra 2009:

• Methods: built a phylogeny of 7 species, classified burrowing (none, simple, complex), and mapped it onto the tree

• Ancestral state: no burrows

• Sister species often differed (e.g., Aztec vs. plateau mouse)

• Conclusion: burrowing evolved independently across species

Punchline: The ancestor didn't burrow; burrowing is derived and evolved independently in different lineages.

What are Morgan's Canon, classical conditioning (Pavlov), and operant conditioning (Skinner), and how do you tell the two conditioning types apart?

Morgan's Canon (C. Lloyd Morgan, 1894): interpret an animal's behavior using the simplest psychological process possible. It pushed for a more scientific approach, in reaction to Romanes' anecdotal, anthropomorphic style.

Classical conditioning (Ivan Pavlov): a novel stimulus is paired with an existing stimulus.
e.g., a bell paired with food, so the dog drools at the bell

Operant conditioning (B. F. Skinner): learning to associate a behavior with a particular consequence, positive or negative. Studied in Skinner boxes.
e.g., a rat presses a lever and gets food

How to tell them apart:

• Classical: stimulus + stimulus. The animal doesn't have to do anything.

• Operant: behavior → consequence. The animal's own action earns the outcome.

Punchline: Morgan's Canon = choose the simplest explanation. Classical = two stimuli get linked. Operant = an action gets linked to its consequence.

How did ethology differ from behaviorism, and what did Lorenz, von Frisch, and Tinbergen each contribute?

Behaviorism (comparative psychology)

• Studied behavior without reference to mental states

• Lab-based, using a stimulus-response paradigm

• Pavlov (classical conditioning), Skinner (operant conditioning)

Classical ethology

• Studied wild animals in nature, through observation and experimentation

• Studied behavior for its own sake

• Focused on instinct

The 1973 Nobel Prize trio:

• Konrad Lorenz: imprinting (goslings followed his boots)

• Karl von Frisch: honeybee sensory perception and communication (waggle dance)

• Niko Tinbergen: fixed action patterns (e.g., goose egg-rolling) and releasers (e.g., red triggers stickleback aggression); also the four questions

Punchline: Behaviorists studied learning in the lab through stimulus-response; ethologists studied instinct in wild animals. Lorenz = imprinting, Von Frisch = bees, Tinbergen = fixed action patterns and releasers.

What are the Three R's of animal research ethics, and what does each one mean?

• Replacement: Substitute live animals with alternatives such as computer models, cell cultures, or less sentient organisms.

• Reduction: Use the minimum number of animals needed for valid results and adequate statistical power.

• Refinement: Modify procedures and care to minimize pain, suffering, and distress.

Statistical Confounders: Third Variable vs History Effect

• Third Variable Problem (Confounding Variable):

  • Two variables appear correlated, but both are actually driven by an unmeasured underlying factor.

  • Classic Example: Ice cream sales and drowning rates correlate, but both are driven by hot summer weather (or city size driving both church count and crime rates).

  • Correction: Controlled experiments or holding confounding variables constant.

• History Effect:

  • An experimental confound where an uncontrolled event or natural change over time (e.g., season shifts, weather, daylight cycles) alters the outcome, but is mistakenly credited to the experimental treatment.

  • Correction: Simultaneous, identical control groups run alongside treatment groups.

• Exam Trigger: Questions testing why correlation does not equal causation, or experiments lacking proper time-matched controls across seasons.

QTL Analysis & Gene Linkage Maps

• QTL (Quantitative Trait Locus): A chromosome region containing or linked to genes that influence a continuous, polygenic trait (e.g., behavior, height).

• Linkage Map: The order and relative spacing of genetic markers based on recombination frequency, not physical base-pair distance.

• QTL Mapping: Cross distinct lines, then correlate markers with trait variation in the offspring to find which chromosome regions affect the trait.

  • Example: deer mouse burrowing (Weber et al. 2013).

• Exam trigger: Locating the genetic basis of complex, continuous behaviors that don't follow simple Mendelian ratios.

• Watch out: QTL mapping finds regions, not the exact gene. Pinpointing the specific gene takes further work.

What is a gene knockout study, what can it show about behavior, and what are its limits?

Knockout: a procedure that eliminates the expression of a gene. Compare knockout animals with wild-type animals.
(Knockdown = reduces expression, as in FoxP2 zebra finches.)

Shows: a gene's function, by testing what changes when it's gone. It's experimental, not correlational.

Limit: behavior comes from genes + environment. A knockout shows a gene has a role, not that it's the sole cause.

Punchline: Remove a gene, compare to wild-type, and see what changes.

Hook: "Unplug it and see what breaks."

What did Bastock (1956) show with the yellow mutation in Drosophila, and why was backcrossing essential?

• System: Compared courtship and mating success of wild-type vs. yellow mutant male Drosophila melanogaster.

• Critical control (backcrossing):

  • The yellow mutation was repeatedly backcrossed into a wild-type background, so the flies differed essentially only at the yellow locus.

  • Purpose: Attribute any behavioral difference to the yellow gene, not to other genetic differences.

• Findings:

  • Wild-type males: vigorous courtship (e.g., wing vibration) and higher mating success.

  • Yellow males: weaker, less frequent courtship and lower mating success.

  • The deficit came from the males' behavior, not from females rejecting the yellow color.

• Exam takeaway: One of the first demonstrations that a single gene can alter a complex behavior and reduce reproductive success.

Ross (1997): Fire Ants & The Gp-9 Gene

• System (Solenopsis invicta):

  • Monogyne: Exactly one queen per colony (rivals are executed).

  • Polygyne: Multiple queens tolerated in the same colony.

• Genetics at the Gp-9 Locus:

  • BB (Homozygous dominant): Monogyne only. Workers execute any queen lacking the B allele and reject extra queens.

  • Bb (Heterozygous): Polygyne. Workers accept multiple reproductive queens.

  • Note on bb: Lethal recessive (dies before reproducing).

• Exam Punchline: Social structure (single vs. multiple queens) is governed by alleles at a single major gene locus (Gp-9 encodes an odorant-binding protein that regulates queen recognition pheromones).

What is broad-sense heritability (H²), what does it include, and when is it the useful measure?

• The Big Idea: The proportion of phenotypic variance due to all genetic variance.

• $$H^2 = \frac{V_G}{V_P} = \frac{V_A + V_D + V_I}{V_P}$$

  • V_A (Additive): Independent allele effects that work alone.

  • V_D (Dominance): Allele interactions at the same locus (Aa).

  • V_I (Epistasis): Gene interactions across different loci (Gene B + Gene C).

• The Big Trap:

  • In sexual reproduction, meiosis tears allele combinations (V_D and V_I) apart.

  • In sexual species, H² overestimates the response to selection. Use h² instead.

• When H² applies: When whole genotypes are shared intact, as in clonal or asexual reproduction, or in identical-twin comparisons.

• Rule: H² ≥ h² always.

What is narrow-sense heritability (h²), why does it exclude dominance and epistasis, and how is it measured?

• The Big Idea: h² is the proportion of total phenotypic variance that's due to additive genetic variance.

  $$h^2 = \frac{V_A}{V_P}$$

• Why drop Dominance (V_D) and Epistasis (V_I)?

  • They depend on combinations of alleles (Aa at one gene, or gene B + gene C together).

  • Meiosis breaks these combinations apart, since each gamete carries only one allele per gene.

  • So a parent's special combo gets scrambled, and the offspring may not inherit its effect.

  • Additive effects don't depend on partners, so each allele's effect is passed on consistently.

• How to Measure: Slope of the parent-offspring regression. The midparent slope equals h², and a single-parent slope equals ½ h².

• Exam Rule: Response to selection is predicted by h² (V_A), via the breeder's equation, R = h²S.

Closed-Ended vs. Open-Ended Learners

• Closed-Ended Learners (e.g., zebra finch):

  • Learn song only during an early sensitive (critical) period, and must hear a conspecific tutor as a juvenile.

  • Song crystallizes and stays fixed in adulthood.

• Open-Ended Learners (e.g., canary, starling):

  • Keep vocal plasticity for life and can modify or add songs as adults. Canaries revise their song seasonally.

• FoxP2:

  • Its expression in Area X (a song-learning brain region) is needed for accurate song learning. Knockdown leads to incomplete, inaccurate copying of the tutor.

Reaction Norms: Main Effects (V_G, V_E) vs. Interaction (V_GEI)

Reaction norm: how one genotype's behavior changes across different environments.
→ On the graph, each line = one genotype's reaction norm.

The graph:

• x-axis = environment (e.g., fed vs. starved)

• y-axis = behavior

• one line per genotype (e.g., rover, sitter)

Ask 3 questions:

1. Is one line higher? → genes matter (VG)

2. Are the lines tilted? → environment matters (VE)

3. Are the lines NOT parallel? → GEI: the environment affects one genotype more than the other (VGEI)

Kent's flies: fed = lines together; starved = rover drops, sitter stays flat → not parallel → GEI.

Formula: VP = VG + VE + VGEI (total variation = genes + environment + their interaction)

What did Kent et al. (2009) find about rover and sitter flies when fed vs. starved, and why is it a gene–environment interaction?

• Flies: Rovers and sitters have different versions of the foraging gene. The names come from a larval crawling test.

• Test: How often adult flies left sugar to explore a maze, when fed vs. starved.

• Fed: rovers ≈ sitters (~40%). The gene makes no difference.

• Starved: sitters ~30%, rovers ~18%. The gene makes a big difference.

• Why: Rovers burn energy faster, so when starving they stay and eat instead of exploring (like a hyper friend who skipped meals parking at the snack table).

• GEI: A gene's effect depends on the environment. Here it's zero when fed and large when starved.

• Graph: The lines start together and spread apart. Non-parallel = GEI. They don't need to cross.

• Memorize: Fed = same. Starved = rovers drop more. Gene effect depends on environment = GEI.

Behavioral Syndromes / Animal Personalities

• Animal Personality: Consistent individual differences in behavior across time or contexts (e.g., always bold vs. always shy).

• Behavioral Syndrome: A correlated suite of different behaviors across contexts (e.g., bold toward predators also goes with aggressive toward rivals and fast at foraging).

• Limited Plasticity: Behaviors are linked, often through shared genetic or physiological mechanisms, so animals can't just flip a switch to behave optimally in every scenario.

• Maladaptive Carryover: A trait that helps in one context hurts in another.

  • A very bold fish eats more food but is more likely to be eaten by a predator.

  • Aggressive female fishing spiders sometimes eat males before mating, because their aggression toward prey spills over into courtship.

• Exam trigger: Why animals show "suboptimal" behavior instead of adjusting perfectly to every situation.

What did Wolf et al. (2007) propose about animal personalities, and how does the asset protection principle explain them?

The Question: Why are animals locked into consistent personalities (bold vs. shy) instead of being flexibly adaptive to every situation?

The Study (Wolf et al. 2007): A theoretical model showing that life-history trade-offs between current and future reproduction can produce consistent personalities.

The Mechanism (Asset Protection Principle):

• Bold individuals: Prioritize current reproduction. They take bigger foraging and mating risks today because they have less future fitness to lose.

• Shy individuals: Prioritize future reproduction. They have higher residual reproductive value, meaning more future fitness to lose, so they play it safe today ("protect their assets").

Why Both Persist: Neither strategy is universally better. Both can achieve similar lifetime fitness through different paths.

• Bold: High payoff now, shorter lifespan.

• Shy: Lower payoff now, longer lifespan.

Exam Trap: Personalities exist not because one is superior, but because future reproductive expectations shape current risk-taking. It's a model, so it predicts this rather than proving it in real animals.

Habituation & Owen and Perrill (1998): The Dear-Enemy Hypothesis

Habituation: the simplest form of learning: a reduction and then lack of response to a stimulus over time.

Dear enemy hypothesis (as tested): a territorial male's aggression toward a rival varies with familiarity, because he habituates to familiar neighbors.

Methods:

• Territorial male green frogs at 4 ponds

• Played synthesized rival calls (350 Hz and 450 Hz) from speakers 1–2 m away

• Recorded the focal male's calls and movements toward the speaker

• Key fact: aggressive calls are lower-frequency than advertisement calls

Results:

• Males moved toward the speaker less and less after the first broadcast, which is habituation

• Call sequence: advertisement → aggressive (when the rival first calls) → back to advertisement (after habituating)

• A new rival (the 350 Hz call) triggered aggressive calls again

Conclusion: males habituated to rival calls, which supports the dear enemy hypothesis.

Punchline: Frogs get aggressive at a new rival's call, then habituate and calm down. A new rival restarts the aggression, so the calm is specific to the familiar one.

How does classical (Pavlovian) conditioning work? Define the US, UR, CS, and CR.

The Core Idea:

• A neutral cue is repeatedly paired with a biologically meaningful stimulus until the cue alone triggers an involuntary response.

• No choice and no trial and error, just an automatic bodily reaction.

• The cue works best when it comes just before the US, so it predicts it.

The 4 Terms:

• US (unconditioned stimulus): naturally triggers a response (food, predator, mate).

• UR (unconditioned response): the unlearned reflex to the US (salivating at food).

• CS (conditioned stimulus): starts as a neutral cue (bell, odor, cage) and becomes the CS after pairing.

• CR (conditioned response): the learned response to the CS alone (salivating at the bell).

Key points:

• The UR and CR are often the same behavior. What differs is what triggers it.

• Extinction: presenting the CS repeatedly without the US makes the CR fade.

• Fitness link: In quail, a CS+ cage increased fertilization success (Adkins-Regan & MacKillop).

What did Adkins-Regan & MacKillop (2003) show about classical conditioning and reproductive success in Japanese quail?

The Question: Does Pavlovian conditioning actually increase reproductive success, not just behavior in the lab?

The Experiment:

• Male Japanese quail were conditioned to associate a cage context with mating:

  • CS+ cage: paired with access to a receptive female.

  • CS− cage: never paired with a female (control).

• Test: Males mated in either the CS+ or the CS− context. Eggs were incubated to measure fertilization.

Results:

• Matings in the CS+ context fertilized more eggs than matings in the CS− context.

• Likely mechanism: The predictive cue triggers anticipatory physiological priming (e.g., more sperm released), improving fertilization.

The Pavlov Connection:

• US: receptive female → UR: sexual response (arousal, sperm release).

• CS: CS+ cage → CR: anticipatory physiological priming.

Exam Punchline: Classical conditioning isn't just a lab trick. It can increase a component of fitness (fertilization success) by preparing the body for reproduction.

What is operant conditioning, what does its learning curve look like, and how does it differ from classical conditioning?

Operant conditioning: trial-and-error learning. Through repetition, the animal learns which actions lead to a reward.
e.g., dogs trained with food rewards; bumblebees learning that yellow flowers hold nectar

Learning curve: errors decline over time. The curve starts high, drops, then levels off, and it varies between individuals (e.g., macaques, bee colonies).

Classical conditioning: a novel stimulus is paired with an existing stimulus, linking the new cue to an innate response.
e.g., Japanese quail and mating cages; toads avoiding chytrid cues

Punchline: Operant = learn which actions pay off, with errors dropping over time. Classical = learn that one cue predicts another.

How is learning linked to brain structure at the micro level (dendritic spines) and the macro level (hippocampus)?

Core idea: Learning and memory are tied to physical brain structure at two scales.

Micro level: dendritic spines and motor learning

• Spines are small protrusions on dendrites where synapses form.

• Mice trained on an accelerating rotarod formed more new spines in the motor cortex than untrained controls.

• New spine formation correlates with learning, and spines that stay stable are linked to long-term retention of the skill.

Macro level: hippocampus and spatial memory

• The hippocampus supports spatial memory and navigation.

• Food-caching birds (e.g., chickadees, nutcrackers) have a larger relative hippocampus than non-caching relatives.

• This is a comparative, across-species correlation, not an experiment.

Pigeon Responses in the Monty Hall Dilemma

Setup: pick 1 of 3 doors (1 prize, 2 duds). One dud is revealed.

Stay or switch?

• Stay wins 1/3 of the time

• Switch wins 2/3, the optimal move

Results (repeated trials with rewards):

• Pigeons: switched about 36% on Day 1, then about 96% by Day 30

• Humans: switched about 56% in the first block and only about 65% in the last block

Takeaway: through trial-and-error (operant) learning, pigeons learned the optimal strategy almost perfectly. Humans improved only slightly and stayed far from optimal.

Punchline: Pigeons learned to switch almost every time; humans didn't. Trial-and-error feedback led pigeons to the best strategy.

What's the difference between local enhancement and public information, and how did the stickleback experiments distinguish them?

The distinction:

• Local enhancement: Drawn to a location simply because others are there. It points you to a spot, not to how good that spot is.

• Public information: Judging patch quality by watching others' feeding success (reward rate).

Stickleback experiment:

• Only group size visible: The observer goes to the larger group (6 fish over 2), which is local enhancement.

• Feeding rate visible: The observer picks the smaller group that's feeding faster, which is public information.

Memory hack:

• Local: location and bodies (following the crowd).

• Public: performance and bites (watching them eat).

Exam trap: Responding to others' presence is local enhancement. Tracking their feeding success is public information.

Insight learning vs. operant conditioning: what's the difference, what's the Kandula example, and how does forebrain size relate to cognition?

Cognition: the ability to generate and store mental representations of the physical and social environment to motivate behavior or solve problems.

Forebrain size (Lefebvre et al. 1997): across 322 reports of bird feeding innovations, foraging innovation positively correlated with relative forebrain size. Cognitive ability appears linked to forebrain size (a correlation).

Insight learning: spontaneous problem solving without trial-and-error learning.

• Kandula (Asian elephant): with no experience, he moved a large cube under hanging fruit and stood on it to reach the food.

Operant conditioning: trial-and-error learning through repetition that leads to rewards. The learning curve shows errors declining over time.

Key difference: operant = gradual improvement over many tries; insight = sudden solution with no trial and error.

Punchline: Operant is a slow climb; insight is an instant jump. Birds with bigger forebrains invent more new foraging tricks.

What counts as a behavioral tradition or culture in animals, what must be ruled out, and what are the classic examples?

Behavioral tradition: differences in behavior among populations, transmitted across generations through social learning (using others as a source of information).

Animal culture: differences in multiple behavioral traditions among populations.

Must rule out: differences caused by environmental variation (or genetic differences) instead of social learning.

Examples:

• Song dialects: learned songs vary geographically (yellow-naped Amazon parrots).

• Chimp nut-cracking: neighboring groups use different tools (wooden vs. stone hammers). Being neighbors makes a purely environmental explanation unlikely.

• Dolphin sponging: dolphins use marine sponges to dig up prey on a seafloor strewn with sharp rubble.

• Also on slides: chimp grooming style varies by community; orca and dolphin hunting techniques are culturally transmitted.

Punchline: A tradition is a population difference passed down by social learning, not by genes or environment. Multiple traditions = culture.

What did Riley et al. (2005) show about whether recruit bees use the waggle dance vector or just follow odor?

Waggle dance: a scout's dance conveys the direction and distance to food.

Question: Which matters more for finding food, odor or the waggle dance?

Methods:

• Feeding station 200 m due east of the hive

• Recorded wind speed and direction

• Tracked recruits with radar transponders

Results:

• Most recruits flew east, the direction the dance indicated

• They even corrected for crosswind instead of just drifting downwind

• After about 200 m, they switched to circling (search) flights

• Wind data showed no odor from the station reached them

• Only 2 of 19 recruits actually found the food

Conclusion: the dance does communicate distance and direction, since bees flew the right vector without odor. But bees need additional cues (odor) to pinpoint the exact spot.

Punchline: Recruits follow the dance's vector to the right general area, then need odor to find the exact food. The dance gets them close; the nose closes the deal.

What did Nicholls & Goldizen (2006) find about habitat density and satin bowerbird call frequency, and what hypothesis does it support?

The Question: Does vegetation density shape the pitch (frequency) of bird calls?

The Hypothesis: Acoustic Adaptation Hypothesis

• Signals evolve to transmit well in the habitat where they're used.

• High frequencies scatter off leaves and branches and attenuate (fade) quickly in dense vegetation.

• Low frequencies have longer wavelengths, pass around obstacles, and attenuate less.

The Study:

• Recorded male satin bowerbird advertisement calls across 18 sites in Australia.

• Measured tree stem density (stems > 5 cm wide) at each site.

The Result:

• Denser sites → calls with lower minimum and dominant (loudest) frequencies.

• More open sites → higher-frequency calls.

Exam Punchline:

• Habitat structure shapes signal design to reduce attenuation. Dense forest favors lower frequencies.

• Watch out: It's a correlational field study across sites, not an experiment.

What did Kuchta, Krakauer & Sinervo (2008) show about Batesian mimicry in Ensatina salamanders?

Batesian mimicry: a palatable mimic resembles an unpalatable model.

Question: Is the yellow-eyed salamander (Ensatina eschscholtzii xanthoptica) a Batesian mimic of toxic Taricha newts?

• Most Ensatina are cryptic; the yellow-eyed form is bright, like the aposematic newt (yellow eyes, orange underside).

Methods: Western scrub jays

• Day 1: fed an edible salamander

• Day 2: fed a toxic newt

• Days 3–4: fed the yellow-eyed mimic or a cryptic, palatable Ensatina

Results:

• 7 of 10 jays never touched the toxic newt

• All jays approached the cryptic Ensatina faster than the mimic

Conclusion: the yellow-eyed salamander is a Batesian mimic of the toxic newt.

Punchline: After tasting the toxic newt, jays hesitated to attack its harmless look-alike, so the mimicry works.

How did Schmidt & Ostfeld (2008) use giving-up densities to show that gray squirrels eavesdrop on blue jays?

The Core Logic: Squirrels cache nuts for winter, but blue jays steal caches. If thieves are nearby, caching food is less worth it.

The Setup:

• Unshelled nuts: carried off and cached, so they can be stolen later.

• Shelled nuts: eaten on the spot, so they can't be stolen.

• Blue jay calls were played near (25 m) vs. far (125 m).

Findings:

• Jays near: Squirrels left more unshelled nuts behind (higher GUD), because cached food is worth less when thieves are around.

• Shelled nuts: GUD didn't change, since food eaten immediately can't be stolen.

Vocabulary:

• GUD (giving-up density): food left in a patch when the animal quits.

• Quit early → more food left → high GUD → higher perceived cost.

Exam Punchline: Squirrels eavesdrop on jay calls (signals not meant for them) to assess theft risk, and they reduce only the foraging that produces stealable food.

How do vervet monkey and tufted titmouse alarm calls differ in the information they convey?

Vervet monkeys (Seyfarth, Cheney & Marler 1980): predator type

• A different call for each predator, each triggering its own escape:

  • Leopard → run up into trees.

  • Eagle → look up and dive into bushes.

  • Snake → stand up and scan the ground.

• Key evidence: Playing the calls back with no predator present still triggered the matching escape, so the call itself carries the meaning (referential calls).

Tufted titmice (Courter & Ritchison 2010): threat level

• Calls include more "D" notes when the threat is higher, and mobbing lasts longer.

• The twist: Smaller raptors (e.g., screech owl) are more dangerous, since they're agile in dense cover. Larger raptors (e.g., great horned owl) are less maneuverable and less of a threat.

• So a smaller predator gets more D notes.

Memory hook: Vervets = a name tag for the predator. Titmice = a danger meter.

Exam trap: Don't assume a bigger predator means more alarm. For titmice, smaller = deadlier = more D notes.

Why are most animal signals honest, and when can dishonest signals persist?

Core idea: Signals stay honest when faking them is impossible or too costly, or when sender and receiver share interests.

3 ways honesty is maintained:

1. Shared interests: both sides benefit from the truth (e.g., honeybee sisters dancing for the colony).

2. Index signals (unfakeable): body size physically limits the signal (e.g., only large toads can produce deep croaks).

3. Costly signals: only high-quality individuals can afford the signal.

   • Wolf spiders: only well-fed males can sustain fast leg-drumming displays.

   • Betta fish: gill flaring interrupts breathing, and flaring drops in low-oxygen water, so it reflects real aerobic stamina.

When dishonesty can evolve:

• When sender and receiver interests conflict (rivals, or predator vs. prey).

• Examples: Batesian mimicry (your Ensatina card) and fireflies that mimic other species' mating flashes to lure prey.

• Key rule: Cheating works only while rare. If lying becomes common, receivers stop responding, so the cheater's success drops as it becomes more common (negative frequency-dependent selection).

Memory hack:

• Honesty = too costly or impossible to fake.

• Dishonesty = works only while rare.

What's the difference between aposematism, Batesian mimicry, and aggressive mimicry? Give an example study for each.

1. Aposematism (honest warning):

• Bright colors advertise toxicity or distastefulness.

• Evidence (Saporito et al. 2007): Clay models of poison frogs were placed in the field, and brown models were attacked about twice as often as brightly colored red-and-blue ones.

2. Batesian mimicry (defensive):

• A harmless prey species copies a toxic model to avoid being eaten.

• Example (Kuchta et al. 2008): The edible yellow-eyed ensatina copies a toxic orange-bellied newt.

3. Aggressive mimicry (offensive):

• A predator or parasite copies a harmless or beneficial model to get close to victims.

• Example (Côté & Cheney): The fangblenny mimics the cleaner wrasse, then bites scales and tissue from client fish that approach expecting to be cleaned.

Exam trap:

• Batesian = defense (prey fakes danger).

• Aggressive = offense (predator fakes friend).

• Müllerian = two harmful species share the same warning signal, so both are honest.

How do capuchins and topi use false alarms, and what's the difference between a bystander (eavesdropper) and an audience effect?

False alarms are cheap, inaccurate signals used when the signaler's and receiver's interests differ.

Capuchins (Wheeler 2009) → for food

• False alarms came mostly from subordinates, when food was clumped, and when the caller was close to the food

• Others reacted to the fake alarm, and the caller got the food

Topi (Bro-Jørgensen & Pangle 2010) → for sex

• Males gave false alarm snorts when an estrus female was about to leave their territory

• The fake snorts were acoustically identical to real ones

• The female stayed, so the male got more matings → supports the sexual deception hypothesis

Bystander (eavesdropper): a third party that picks up a signal meant for someone else. The listener changes its behavior.
e.g., squirrels eavesdropping on jay calls

Audience effect: the presence of bystanders changes the signaler's behavior.
e.g., male fighting fish displayed more aggressively when a female watched, but not a male

Punchline: Topi lie to keep mates; capuchins lie to get food. Eavesdropper = the listener changes. Audience effect = the signaler changes.