Biology 4101 - Behavioural Ecology

1. Biology 4101 - Behavioural Ecology INTRODUCTION

2. COURSE DESCRUPTION A course to explore the relationships between animal behaviour and ecology, emphasizing the behavioural strategies which animals have evolved to enhance their survival and to increase their reproductive success. Topics such as foraging, living in groups, resource defence, sexual selection, parental care, mating systems, altruism and communication will be discussed within a neo-Darwinian framework.

3. Grading: Seminar as Seminarian 20% Seminar as Devil’s Advocate 20% Midterm 25% Essay 25% Participation 10% TOTAL 100%

4. Seminar Format: In any week, seminars will be given by pairs of students based on the paper that is on the course website. One pair of students will act as the “Seminarians”, giving the paper, describing how it was done and what the major conclusions are. The other pair or students will act as “Devil’s Advocates” and point out flaws in the paper. Such flaws could be in experimental design, statistical analysis or the conclusions drawn. Each pair of students will be given 25 minutes to present their seminar and then the remaining time will be for discussion. Your contributions to the discussion period will determine your participation grade. Each pair of students will present one seminar as the Seminarian and one as the Devil’s Advocate. In the first week of class, you must pick a partner and sign up by emailing me which session you and your partner want to do as the Seminarian and which you want to do as the Devil’s Advocate. Anyone not signed up by January 10, 2014 will have partners and subjects assigned arbitrarily by me.

5. BEHAVIOURAL ECOLOGY ASKING QUESTIONS Why is it foraging alone? Why is it foraging here? Is it eating everything or being selective? How does it decide when to fly back to the nest? How does it detect its prey? Does this bird always forage or does it have help? Do its own predators influence its behaviour?

6. BEHAVIOURAL ECOLOGY ASKING QUESTIONS Why does it have this number of chicks? Why is it nesting here? Are all the chicks related to the adult? How does it decide which chicks to feed first? Is the work of feeding shared equally by both parents? Why are the chicks making so much noise?

7. Tinbergen’s Four Questions (The Four Whys) Why is this bird singing? Niko Tinbergen (1907 – 1988) • Causation (physiological explanation) • sensory/nervous systems • hormonal systems • - skeleto-muscular system PROXIMATE FACTORS Development/Ontogeny - learning, genetic disposition, developmental mechanisms Adaptive Advantage/Function - reproductive success - what are the selective pressures ULTIMATE FACTORS Evolutionary History/Phylogeny - how song evolved in the bird’s ancestors

8. UNDERLYING CONCEPTS IN BEHAVIOURAL ECOLOGY 1) Natural Selection (Darwin’s and Genetic) 2) Group vs. Individual Selection 3) Strategies, Costs and Benefits 4) Evolutionarily Stable Strategy 5) Phenotypic Plasticity and Reaction Norms

9. UNDERLYING CONCEPTS IN BEHAVIOURAL ECOLOGY 1) Natural Selection (Darwin’s formulation) Observation Deduction All organic populations can exponentially. In spite of Obs. 1, they don’t. There is some kind of struggle for existence. This differentialreproduction/survival is natural selection All members of a species are not the same. Differences in individuals are passed to their offspring. 2. Some members of a species are better equipped to survive and reproduce than others.

10. TOOLS FOR STUDYING BEHAVIOURAL ECOLOGY 1) Natural Selection (modern genetic formulation) a. All organisms have genes coding for proteins. Proteins, in turn, regulate development of senses, nervous systems and skeleto-muscular structure. b. Genes are present in two or more forms (alleles) which code for slight differences in proteins which, in turn, cause differences in development. Consequently, there is variation in the population c. An allele that has more surviving copies of itself and any of its alternatives will eventually replace those alternatives in the population. Natural selection is the differential survival of alleles via their effects on reproductive success.

11. How do genes affect complex behaviour patterns? Not a clear picture e.g. melanocortin-1 receptor (MC1R gene) In lesser snow geese (Anserchencaerulescens): ‘blue’ phase ‘white’ phase Preferential mating by phase Mundy et al, 2004. Science 303:1870

12. How do single genes affect complex behaviour patterns? Not a clear picture e.g. melanocortin-1 receptor (MC1R gene) In rock pocket mouse (Chaetodipusintermedius): Selective predation by owls Nachman et al, 2003. PNAS 100:5268

13. How do multiple genes affect complex behaviour patterns? Black-capped warbler Sylvia atricapilla German population - migratory Canary Islands population – non-migratory

14. How do multiple genes affect complex behaviour patterns? Sylvia atricapilla 10 5 German Number of half hours with migratory restlessness Hybrid Canary Island 0 50 100 Time (Days)

15. 2) Group vs. Individual Selection V.B. Wynne Edwards – Group Selection S S A A S S S S A A A A S S A A S A S S A A S A S A S A S A Selfish Population -overexploits resources and dies out Altruistic Population -doesn’t overexploit resources and survives

16. 2) Group vs. Individual Selection At what level does natural selection operate? Species of bird Fledging Young Replace previous? --- 1.8 Genetically determined 2.7 Mutant (3 egg) Yes Yes 3.2 Mutant (4 egg)

17. Can this go on indefinitely? Number of fledglings hatched Increase in Increase in number of ≠ number of eggs offspring Number of eggs laid

19. 3) Strategies, Costs, and Benefits Cost –any factor that reduces reproductive success (directly or indirectly) Benefit –any factor that increases reproductive success (directly or indirectly) Strategy – a set of behavioural courses of action with a given survival value under a particular set of conditions In a successful strategy C B C < B or <1

20. 4) Evolutionarily Stable Strategy (ESS) An evolutionarily stable strategyis one, if adopted by all the members of a population cannot be invaded by a mutant strategy can invade. John Maynard Smith (1920-2004) George R. Price (1922-1995)

21. ESS example – Hawk-Dove Game Hawk - will always fight opponent, may injure opponent or may be injured Dove- will never fight opponent. Payoffs (gains in fitness from a contest) Winner (Victor) V = 50 Loser L = 0 Injury Cost C = -100

22. ESS example – Hawk-Dove Game Payoffs (gains in fitness from a contest) Winner (Victor) V = 50 Loser L = 0 Injury Cost C = -100 Assumptions: 1) When Hawk meets Hawk, half of the time it wins, half of the time it’s injured. 2) Hawks always beat Doves. 3) Doves always retreat when meeting a Hawk 4) When Dove meets Dove, the resource is shared OPPONENT Hawk Dove Hawk ½ V - ½ C = -25 V = 50 ATTACKER L = 0 ½ V = 25 Dove

23. ESS example – Hawk-Dove Game Is either strategy an ESS? Mutant Dove strategy If population is all Hawks NOT AN ESS Payoff/contest = -25 Payoff/contest = 0 Mutant Hawk strategy If population is all Doves NOT AN ESS Payoff/contest = 50 Payoff/contest = 25

24. 5) Phenotypic Plasticity and Reaction Norms Parus major – over 47 years – first egg laying date advanced by 14 days Hypotheses 1) Response to environmental cues? 2) Microevolutionary change?

25. 5) Phenotypic Plasticity and Reaction Norms Hypotheses ✔ 1) Response to environmental cues? 2) Microevolutionary change? Reaction norm – if phenotypic variation is continuous, the relationship between the phenotype and the environment for each genotype.

26. 5) Phenotypic Plasticity and Reaction Norms Britain The Netherlands Reaction norm – if phenotypic variation is continuous, the relationship between the phenotype and the environment for each genotype.

27. Next time – Hypothesis Testing and Foraging Economics