Animal Behavior Lecture Notes PDF

 Learning Objectives Why is behavior important? Discuss the differences between proximate and ultimate causations of behaviors; identify examples Identify and explain fixed action patterns and learning Explain the optimal foraging model Distinguish between different mating...

 Learning Objectives Why is behavior important? Discuss the differences between proximate and ultimate causations of behaviors; identify examples Identify and explain fixed action patterns and learning Explain the optimal foraging model Distinguish between different mating systems What are altruistic behaviors? Discuss kin selection  Behavior Study of behavior = Ethology Behavior – the sum of an organism’s responses to external and internal stimuli; actions carried out by muscles under control of the nervous system  Behavior Behavior … – is essential for energy consumption  Behavior Behavior … – is essential for reproduction  Behavior Behavior … – contributes to homeostasis  Behavior Behavior … – influences survivability – subjected to natural selection  Behavioral Ecology Behaviors can be categorized as innate (does not require experience) or learned (requires experience)  Behavior Study of behavior = Ethology Behavior – the sum of an organism’s responses to external and internal stimuli; actions carried out by muscles under control of the nervous system Understanding behavior requires answering four questions  Behavioral Ecology Proximate Causation – “how” a behavior occurs – Stimulus and physiological response – Combination of nature (genes) and nurture (environment) in shaping behavior. Ultimate Causation – “why” a behavior occurs – Influence on survival and reproduction – Evolutionary history Understanding behavior requires answering four questions Proximate Causation Ultimate Causation  Proximate Causation Question 1: What stimuli trigger behavior? Question 2: How does experience influence behavior? – Innate & learned responses – Combination of nature (genes) and nurture (environment) in shaping learning and behavior Proximate Causation – Innate Behavior Fixed action pattern – unlearned response to external stimuli – Sign stimulus – external trigger for behavior – E.g., three-spined stickleback Proximate Causation – Innate Behavior Environmental stimuli – E.g., circadian rhythms; migration Proximate Causation – Innate Behavior Animal communication – visual, chemical, tactile, auditory – E.g., vocalizations, pheromones, dances Fig. 51.4  Proximate Causation – Learning Learning – modification of behavior based on specific experiences – E.g., imprinting – establishment of a long-lasting behavioral response to a particular individual or object. Takes place only during a specific time period in development (sensitive period) Konrad Lorenz, Austrian zoologist  Proximate Causation – Experience Learning – modification of behavior based on specific experiences – E.g., spatial learning – memory based on environmental space  Proximate Causation – Experience Learning – modification of behavior based on specific experiences – E.g., associative learning – memory based on associations between experiences Fig. 51.9  Proximate Causation – Experience Learning – modification of behavior based on specific experiences – E.g., associative learning Behavior – survivability - evolution Monarch butterfly Viceroy butterfly  Learning Learning – modification of behavior based on specific experiences – E.g., Cognition – process of knowing that involves awareness, reasoning, recollection, and judgment  Learning Learning – modification of behavior based on specific experiences – E.g., Cognition – Includes problem solving, reasoning, and tool use  Proximate Causation – Experience Learning – modification of behavior based on specific experiences – E.g., social learning – observed behaviors of other individuals Vervet monkeys give specific calls for different predators  Ultimate Causation Question 3: How does behavior affect survival and reproduction? Question 4: How has natural selection shaped behavior? Ultimate Causation – Survival & Reproduction Differing foraging strategies affect success Optimal foraging theory – maximum benefits of foraging at lowest cost Ultimate Causation – Survival & Reproduction Mating behavior and mate choice play a major role in determining reproductive success E.g., seeking or attracting mates, choosing among potential mates, competing for mates, and caring for offspring Ultimate Causation – Survival & Reproduction Mating systems – variations in mating systems and mate choice lead to different behaviors – Courtship: animals exchange signals to assess potential mates, avoid inbreeding, and ensure mating with the same species Ultimate Causation – Survival & Reproduction Mating systems – variations in mating systems and mate choice lead to different behaviors – E.g., Monogamy (single mate) Ultimate Causation – Survival & Reproduction Mating systems – variations in mating systems and mate choice lead to different behaviors – E.g., Monogamy (single mate) vs. Polygamy (multiple mates) Ultimate Causation – Survival & Reproduction Mating systems – Sexual dimorphism: males and females differ in appearance that varies with the type of mating system. – Monogamous species, males and females often look very similar. Polygamous species, the sex that attracts multiple mating partners is typically showier and larger. Ultimate Causation – Survival & Reproduction Mating systems – variations in mating systems and mate choice lead to different behaviors – E.g., parental care with altricial offspring vs. precocial offspring Ultimate Causation – Survival & Reproduction Mating systems in seabirds – Typically long-term or life-long pairing (monogamous) – Elaborate courtship and mating rituals – E.g., albatrosses (life-long, extensive parental care) Ultimate Causation – Survival & Reproduction Mating systems in seabirds – Typically long-term or life-long pairing (monogamous) – Elaborate courtship and mating rituals – E.g., albatrosses (life-long, extensive parental care) Ultimate Causation – Survival & Reproduction Mating systems in seabirds – Typically long-term or life-long pairing (monogamous) – Elaborate courtship and mating rituals – E.g., albatrosses Ultimate Causation – Survival & Reproduction Mating systems in seabirds – Exception! – E.g., crested auklets –bonded for only one breeding season. Mutual sexual selection –crest length & tangerine smell  Social Behavior Advantages of living in groups – Finding food, capturing food – Protection from environmental conditions – Protection from predators  Social Behavior Disadvantages of living in groups – Competition among group members – Groups are easier to spot by predators – Diseases can spread quickly  Social Behavior Kin Selection (Altruistic behaviors): natural selection that favors traits that increase the reproductive success of an organism's relatives, even if it comes at a cost to the organism's own survival and reproduction E.g., alarm calls, non-parent rearing/protection  Social Behavior Altruistic behaviors: – Why would these behaviors evolve? – fitness includes a direct (individual’s reproduction) and indirect component (relative’s reproduction) Selection that favors the spread of alleles (genes) that increases indirect fitness – kin selection  Example of Kin Selection Eusociality –cooperative group where typically one female is reproductively active and the nonbreeding individuals care for the young or protect and provide for the group E.g., naked mole rats (queen is aggressive to non-relatives)  Example of Kin Selection Reciprocal altruism – resource sharing – E.g., blood sharing in vampire bats  Social Behavior Humpback whales – True altruism: behaviors that benefit their own species and other species from killer whales  Summary Proximate Causation is “how” a behavior occurs and Ultimate Causation is “why” a behavior occurs Behaviors can be categorized as innate (does not require experience) or learned (requires experience) – Innate includes Fixed action patterns, Environmental stimuli, communication (visual, chemical, tactile, auditory) – Learned includes imprinting, spatial learning, associative learning, cognitive learning, social learning Causes of behavior are related to food (optimal foraging theory), reproduction (mating systems) and survival