1. Polygyny Males: Lower PI and Greater Variance Reproductive Success Male-Male Competition Female Choice

2. Polygyny White-bearded Manakin (Manacus manacus) Male-dominance polygyny Lek Males Display, Interact Aggressively Females Choose Mates

3. White-bearded Manakin Male

4. Polygyny Lekking Systems High Variance in Male Mating Success Females Prefer “Central” Males Lekking Common: Birds, Mammals Found in Some Insects

5. Polygyny Lekking Systems Male Dominance Obtain Central Position Direct/Intrasexual Competition Female Choice: Indirect Male Competition

6. White-bearded Manakin Shorey, L. 2002. Behavioral Ecology and Sociobiology 52:451-457. Northern Trinidad

7. White-bearded Manakin Concentrated Lek Each Male Displays on “Court” Clears Court of Leaves Emergent Saplings: Acrobatics Males Fight: Dominance, Position Males Display: Attract Females

8. White-bearded Manakin Correlates Male Mating Success Size (Tarsus Length, +) Condition (Extra Mass, +) Distance from Lek Center (-) Large Males at Lek Center ?

9. White-bearded Manakin

10. Males Compete for Central Positions Larger Males More Likely Dominant, More Likely Central Lek Centrality: Cue for Female Choice

11. Polyandry Female PI < Male PI Dichromatism: Female Brighter Females Larger, More Aggressive

12. Polyandry Polyandry Relatively Rare “Test” of General Concepts

13. Jacana spinosa Jacana: Polyandry Some Females: Large Territories, Contain 2 – 10 Male Nesting Territories Females Provide Eggs; Males Care for Brood

14. Jacana spinosa

15. Polyandry Females More Aggressive, Slightly Larger Than Males Younger Females: Excluded from Breeding New Female Territory Holder: Infanticide, Free Males for New Clutch

16. Polyandry PI Pattern, Intrasexual Selection Follows Conceptual Construct Female Variance in Reproductive Success > Male Variance

17. Polyandry Jacana: Many Clutches Lost to Predation Abundant, Year-Round Food Females Free of Caring for Young Replace Lost Clutch Quickly Males Take Brood Care

18. Monogamy Common in Birds, Rare Otherwise Obligate Monogamy: Offspring Very Low Survival in Absence of Biparenal Care Facultative Monogamy: Females Avoid Already-Mated Males Social Monogamy: Mated Pairs, Promiscuity

19. Monogamy Obligate Monogamy: Offspring Very Low Survival in Absence of Biparenal Care Common in Raptors Found in Rodents, Canids Foraging Demands of Reproduction, Protection of Young

20. Monogamy Social Monogamy: Snapping Shrimp (Alpheus angulatus) Females Brood Eggs Until Larvae Disperse No Parental Care by Males Male PI Lower (?) How Does Social Monogamy Evolve?

21. Monogamy: Snapping Shrimp Territorial Mutualism: Both Sexes Benefit by Sharing a Territory Females Invest In Burrow Construction; Both Occupy Males Aggressively Defend Territory; Both Sexes Avoid Eviction

22. Monogamy: Snapping Shrimp Mate-Guarding by Males Females Molt, Release Eggs, Brood Cycle Repeated Male May Stay with Female Through Multiple Episodes of Reproduction

23. Monogamy: Snapping Shrimp Economics Monogamous Mate-Guarding Population Density: Low Density, Search Time for Mate Extended, Stay & Guard Sex Ratio: Male-Biased, Stay & Guard; Female-Biased, Desert?

24. Monogamy: Snapping Shrimp Mathews, L.M. 2002. Behavioral Ecology and Sociobiology 51:426-432. Field: Population Density Fort Pierce, FL Lab: Sex Ratio

25. Monogamy: Snapping Shrimp Proportion of Males Paired with (Guarding) Females Independent of Shrimp Population Density Social Monogamy Unresponsive to Population Density

26. Monogamy: Snapping Shrimp Sex Ratios Lab: 1, 0.2 Equal Frequency Sexes: Males Stayed with Female 1 Male/5 Females: Males More Likely to Leave Recently Mated Female; Reduced Tendency for Mongamy