Animal Behaviour - Adam Oliver Brownadamoliverbrown.com/wp-content/uploads/2015/09/BIO3176-1-Introduction_2015_3slides.pdf5 BIO 3176: Animal Behaviour BIO 3176: Animal Behaviour Common

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BIO 3176: Animal Behaviour BIO 3176: Animal Behaviour 1

Animal Behaviour

BIO 3176: Animal Behaviour BIO 3176: Animal Behaviour

Course Website

●  www.adamoliverbrown.com ●  syllabus ●  office hours ●  lecture notes ●  discussion forum ●  dates ●  news

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What is Behaviour?

●  Prior to 1860s – Emotions – Habits – Manners – Customs –  Instincts

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Skinner and Hebb ●  All observable processes by which an

animal responds to perceived changes in the internal state of its body or the external world

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Charles Darwin (1859)

● Variation in phenotypic traits that are heritable

● Variation leads to differential survival and/or reproduction

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Natural Selection

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Group Selection

● Wynne-Edwards (1962): Individual characters evolved to favour the survival of the group (family, population, species)

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Human Behaviour

●  Culture ●  Date-rape ●  Altruism ●  Inter-male combats ●  Promiscuity ●  Compassion

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Tinbergen’s 4 Questions (1963)

●  Mechanism (how is behaviour being achieved)

●  Development (how does it take form?)

●  Function (what is it for?) ●  Evolution (where does it

come from?)

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Tinbergen’s 4 Questions (1963)

●  Mechanism (how is behaviour being achieved)

●  Development (how does it take form?)

●  Function (what is it for?) ●  Evolution (where does it

come from?)

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PROXIMATE

ULTIMATE


Proximate Questions

●  What is the link between the genes and the behaviour?

●  Is the behaviour hereditary? ●  How does the behaviour develop? ●  What stimuli trigger the onset of the

behaviour?

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Ultimate Questions

●  Has the behaviour evolved over time? ●  What was the ancestral form of the

behaviour? ●  Why has the ancestral form changed? ●  What is the adaptive value of behaviour?

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Common Shrew (Sorex araneus)

●  1) Sensory systems are most receptive to larger prey

●  2) Learned from previous experience cost/benefit of struggle/payoff

●  3) Maximize foraging efficiency ●  4) Offspring of a lineage of selective

foragers (greater survival value) 13


Theoretical Framework ●  1) Inclusive fitness (Hamilton, 1964) – Alleles affect social interactions to promote

their transmission through generations ●  2) Evolutionarily Stable Strategies (ESS:

Maynard-Smith, 1972) – Adaptive decision-making is frequency

dependent (best thing to do may depend on what others are doing)

●  3) Optimality Theory (Charnov, 1976) – Cost/benefit analysis to decision-making

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Behavioural Paradox ●  Traits exist that don’t seem to

increase individual fitness

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Risky Business

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Why Infanticide?

●  Psycho-social explanation – Abnormal pathological response to

overcrowding ●  Darwinian explanation – Males gain resources by eating infants – Males gain fitness because females re-mate

quicker with them

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Group Selection

●  If first hyp. is correct ●  Beneficiary is not male

but group to which he belongs

●  Testing group selection hypothesis?

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Darwinian Hypothesis

●  1) Do males kill more when food stressed? Do they always consume the infants?

●  2) Do females become sexually receptive faster than when nursing infant? – DNA analysis shows that the next generation

offspring are all sired by new males

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BIO 3176: Animal Behaviour BIO 3176: Animal Behaviour 20


Sex Role Reversals

●  Giant water bug (Hemiptera)

●  Males offer protection of eggs

●  Females may destroy clutch so he re-mates with her

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Questions?

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Documents

Animal Behaviour - Adam Oliver Brownadamoliverbrown.com/wp-content/uploads/2015/09/BIO3176-1-Introduction_2015_3slides.pdf5 BIO 3176: Animal Behaviour BIO 3176: Animal Behaviour Common