1 / 26

Polygyny

Polygyny. Males : Lower PI and Greater Variance Reproductive Success Male-Male Competition Female Choice. Polygyny. White-bearded Manakin ( Manacus manacus) Male-dominance polygyny Lek Males Display, Interact Aggressively Females Choose Mates. White-bearded Manakin Male.

paul
Download Presentation

Polygyny

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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 Sociobiology52:451-457. 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. White-bearded Manakin 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 Sociobiology51:426-432. 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

More Related