Animal behavior Study Guide

📖 Core Concepts Ethology – the scientific discipline that studies animal behaviour. Instinct – inherited, unchangeable tendency to produce a complex response to a stimulus, without reasoning. Learning – behaviour change through experience; lets animals adapt to their environment. Fixed Action Pattern (FAP) – a stereotyped, species‑specific behavioural sequence that, once triggered by a releaser, runs to completion. Releaser (Sign Stimulus) – the external cue that initiates a FAP. Social Group – a collection of conspecifics that interact under defined rules (food sharing, role assignment, reciprocity). Altruism – a behaviour that lowers the actor’s fitness while raising a recipient’s fitness; explained by gene‑centred (inclusive‑fitness) theory. Dilution Effect – as group size increases, each individual’s chance of being preyed upon falls (predator attack rate stays constant). Selfish Herd Theory – individuals at the centre of a group are less likely to be taken by predators than peripheral ones. --- 📌 Must Remember Instinct vs Learning – Instinct = hard‑wired, no experience needed; Learning = requires experience. Habituation – loss of response to a repeatedly presented, irrelevant stimulus. Classical Conditioning – pairing a neutral stimulus with an unconditioned stimulus produces a conditioned response (e.g., Pavlov’s dogs). Imprinting – a brief, critical‑period learning event that establishes species‑specific recognition. Pecking Order – linear dominance hierarchy in chickens; higher‑ranked birds can peck without retaliation. Dilution vs Selfish Herd – both reduce predation risk, but dilution is a statistical effect of group size, while selfish herd is a spatial positioning strategy. Optimal Group Size – the size that maximises net benefits (predator avoidance, cooperative hunting) and minimises costs (disease, competition). --- 🔄 Key Processes Classical Conditioning (Pavlovian) Present CS (neutral) + US (e.g., food) → UR (salivation). Repeat pairing → CS alone triggers CR (conditioned salivation). Imprinting Occurs during a critical period shortly after hatching. Animal forms a template of parental traits → later preferentially approaches conspecifics matching template. Fixed Action Pattern Activation Detect releaser → neural circuit triggers FAP → behaviour runs to completion (e.g., egg‑rolling in geese). Social Learning Chain Demonstrator performs behaviour → Observer experiences stimulus enhancement (interest in object) → local enhancement (focus on location) → observational learning → possible imitation. Group Size Regulation Benefits (predator dilution, cooperative hunting) increase with size → costs (disease, competition) rise sharply after a threshold → individuals may disperse to achieve optimum. --- 🔍 Key Comparisons Instinct vs Fixed Action Pattern Instinct = broad tendency; FAP = specific, invariant sequence once triggered. Habituation vs Sensitization Habituation: response decreases with repeated irrelevant stimulus. Sensitization (not in outline): response increases after a strong or harmful stimulus. Observational Learning vs Imitation Observational learning: acquire new behaviour by watching; may not copy exactly. Imitation: precise replication of the demonstrator’s actions. Dilution Effect vs Selfish Herd Theory Dilution: statistical reduction of individual risk as group grows. Selfish herd: individuals actively move to centre to lower personal risk. Teaching vs Simple Social Learning Teaching: experienced individual modifies its behaviour to facilitate naive learner’s acquisition of a target skill. Social learning (e.g., observation) may occur without any intentional modification by the demonstrator. --- ⚠️ Common Misunderstandings “All learning is conscious.” – Many forms (habituation, imprinting) occur without conscious intent. “Instinctive behaviours cannot be altered.” – Even strong instincts can be overridden by strong learning (e.g., predator avoidance training). “Altruism always reduces fitness.” – Kin selection and reciprocal altruism can increase inclusive fitness. “Larger groups always equal safer groups.” – Beyond the optimal size, disease spread and competition outweigh predation benefits. “Releaser = stimulus that causes the behaviour.” – It only triggers the pre‑programmed FAP; the animal does not evaluate the stimulus. --- 🧠 Mental Models / Intuition “Trigger‑Run” Model – Think of a FAP as a mousetrap: the releaser is the snap; once set, the trap (behaviour) fires to completion. “Cost‑Benefit Slider” – Visualise group size on a slider: moving right adds benefits (dilution, cooperation) until a tipping point where costs (disease, competition) rise sharply. “Critical‑Period Clock” – Imprinting is a timer that starts at hatching; once it ticks out, the window closes—no later learning of that specific template. --- 🚩 Exceptions & Edge Cases Ectotherms & Light – For temperature‑dependent species, light may act as a seasonal cue rather than a direct behavioural trigger. Fixed Action Patterns in Variable Environments – Some species retain FAP flexibility (e.g., alternative mating displays) when environmental conditions change dramatically. Teaching in Non‑human Animals – Rare, but observed in certain mammals (e.g., meerkats) and birds (e.g., scrub jays). --- 📍 When to Use Which Identify Behaviour Origin If the response appears without prior experience → label Instinct/FAP. If the response changes after repeated exposure → consider Learning (habituation, conditioning, imprinting). Choosing a Learning Category Simple decline in response → Habituation. Association between two stimuli → Classical Conditioning. Time‑limited early‑life learning → Imprinting. Observer watches and later performs a similar but not identical action → Observational Learning. Observer copies the exact motor pattern → Imitation. Assessing Group Benefits Predation pressure high → prioritize Dilution and Selfish Herd considerations. Resource competition severe → weigh Disease/Competition Costs more heavily. --- 👀 Patterns to Recognize Repeated, irrelevant stimulus → no response → likely habituation. Presence of a demonstrator + increased attention to object/location → stimulus/local enhancement. Behaviour that, once started, cannot be stopped → classic fixed action pattern. Linear dominance interactions (pecking order) → look for consistent “winner‑loser” hierarchies. Group size vs. predator attack data – a plateau in predation risk suggests optimal group size. --- 🗂️ Exam Traps Confusing “releaser” with “reward.” – Releasers trigger FAPs; rewards are outcomes of learning processes. Assuming all social learning is imitation. – Many animals learn without exact copying; the distinction is tested. Choosing “larger group = always better” – Questions may ask for the point where costs outweigh benefits. Mixing up “habituation” with “sensitization.” – Remember habituation = decreased response; sensitization = increased response. Attributing altruism to “selfish motives.” – Exams often test inclusive‑fitness explanations versus true self‑interest. ---