Behavioral Ecology

1. Behavioral Ecology Photo from Wikimedia Commons

2. Ethological Underpinnings of Behavioral Ecology Konrad Lorenz Instinct, imprinting, etc. Photo from http://www.dabase.org/lorenz.htm

3. Ethological Underpinnings of Behavioral Ecology Niko Tinbergen Four questions subsumed under Proximate vs. Ultimate Causes; questions concerning, respectively, how a behavior is produced and why it evolved (i.e., evolutionary Benefit / Cost Ratio) Photo of Tinbergen from Wikimedia Commons

4. Ethological Underpinnings of Behavioral Ecology Karl von Frisch Waggle Dance Of his chosen study organism von Frisch said: “The honey bee is like a magic well: the more you draw from it, the more there is to draw.” Photo of von Frisch from Wikimedia Commons

5. Ethological Underpinnings of Behavioral Ecology Konrad Lorenz Niko Tinbergen Karl von Frisch Nobel Prize – 1973 Photo from Wikimedia Commons

6. Genes can influence behavior, so behavior can evolve E.g., artificial selection experiments suggest a genetic basis for “migratory activity” Artificial Selection For higher proportion of migrants For lower proportion of migrants Pulido (2007) BioScience, Fig. 2

7. Foraging Behavior E.g., ambush predator and female fly prey (also illustrates another cost of sex) Photo from Wikimedia Commons

8. Optimal Foraging Theory Items with high profitability (P) are generally preferred E P = t E = net energy value, i.e., energy gained minus energy invested t = encounter time & handling time invested in obtaining & processing the food Photo from http://www.rspb.org.uk/community/ourwork/b/biodiversity/archive/2013/02/18/ guest-blog-in-the-still-of-the-night.aspx

9. Optimal Foraging Theory Conceptual model of OFT Net energy gained = (Total energy obtained) – (Cumulative energy investment) Drops off as animal cannot carry nor ingest more Cain, Bowman & Hacker (2014), Fig. 8.6

10. Optimal Foraging Theory Marginal Value Theorem as applied to profitability of foraging patches Within a patch, the marginal value for longer time has diminishing returns Slopes of straight, solid lines = Energy gained / time Tangent maximizes profitability (slope) & determines optimal giving up time Cain, Bowman & Hacker (2014), Fig. 8.8

11. The Ecology of Fear Foraging (and other) decisions can be modified by predators E.g., caged grasshoppers foraging in the presence or absence of the risk of predation, i.e., with or without a spider (mean s.e.m. shown) Beckerman et al. (1997) Proceedings of the National Academy of Sciences, Fig. 1

12. The Ecology of Fear Prey sometimes communicate their awareness of predators to those predators E.g., stotting / pronking Photo from Wikimedia Commons

13. Social Behavior Photo of social grooming from Wikimedia Commons

14. Social Behavior E.g., Optimal Group Size Consider the variable Benefit / Cost Ratio Should an individual remain alone or join another to form a group of 2? Should an individual join a group of 2 or 5? What is the optimum group size? What are likely benefits and costs? Cain, Bowman & Hacker (2014), Fig. 8.22

15. Reproductive Behavior Photo from Wikimedia Commons

16. The Evolution of Competitive Males & Choosy Females (and sometimes the reverse) Parental Investment is“any investment by the parent in an individual offspring that increases the offspring's chance of surviving (and hence reproductive success) at the cost of the parent's ability to invest in other offspring” (Trivers 1972) Maternal investment = nursing Paternal investment = brood-pouch “pregnancy” Anisogamy Photomicrograph of human egg and sperm cells from Cain, Bowman & Hacker (2014), Fig. 7.7; photo of suckling manatee from http://mammalssuck.blogspot.com/2013/11/mega-mammal-milk-analysis.html; photo of “pregnant” seahorses from http://www.scubadiveasia.com/blog/best-dad-award-goes-to-the-seahorse/

17. Male-Male Competition E.g., male pollen grains compete to fertilize female ovules Photomicrographs from http://prometheuswiki.publish.csiro.au/tiki-index.php?page= Spikelet+sterility+and+in+vivo+pollen+germination+and+tube+growth+under+high-temperature+stress+in+rice

18. Female Choice – Courtship E.g., courtship in the peacock spider (Maratusspeciosus) Photo of peacock spider (Maratusvolans) from Wikimedia Commons

19. Copulatory Courtship & Cryptic Female Choice E.g., male damselfly genitalia (aedeagi, plural of aedeagus) Photo of Maria Fernanda Cardosa’s sculptures of male damselfly genitalia from http://livingwithinsects.wordpress.com/2012/04/30/insect-reproductive-morphology/

20. Mating Systems Monogamy Polygyny Polyandry Promiscuity Photo of horseshoe crabs from Wikimedia Commons

21. Mating Systems “Polygyny occurs if environmental or behavioral conditions bring about the clumping of females, and males have the capacity to monopolize them.” Emlen & Oring (1977) Cain, Bowman & Hacker (2014), Fig. 8.8; schema from Emlen & Orgin (1977) Science, Fig. 1

22. Mating Systems Polygyny Threshold Model Pick a point on the monogamous female curve. The distance to the right to intercept the bigamous female curve is the polygyny threshold, i.e., the habitat quality increase required to make it worthwhile for the female to share a mate. Graphic model from Orians (1969) American Naturalist, Fig. 1

23. Inclusive Fitness & Kin Selection Kin selection exposes the selfish nature of altruism; helping kin can increase one’s inclusive fitness (direct plus indirect fitness) Hamilton’s Rule: rB > C Relatedness * (Benefits to recipient) >(Costs to altruist) W. D. Hamilton Photo of Hamilton from Wikimedia Commons

24. Relatedness r – introduced by Sewell Wright as a measure of consanguinity Generation 1 Mother-daughter r = 1/2 Generation 2 Sister r = 1/2 Cousin r = 1/8 Generation 3 “I would lay down my life for 2 brothers or 8 cousins” J. B. S. Haldane

25. Eusociality in Diploid Organisms For most individuals in the colony the benefits to helping the queen outweigh the costs of sacrificing their own reproduction rB > C Naked Mole Rat Termites Photos from Wikimedia Commons

26. Eusociality in Haplodiploid Organisms For most individuals in the colony the benefits to helping the queen outweigh the costs of sacrificing their own reproduction rB > C Generation 1 Mother-daughter r = 1/2 Sister r = 3/4 Generation 2 Photos of Hymenoptera from Wikimedia Commons

27. Behavioral Ecology Adoption Aggression Anti-Predator Behavior Begging Breeding Brood Parasitism Cannibalism Communication Cooperation Copulation Dispersal Dominance Hierarchies Family Dynamics Flocking Grooming Habitat Selection Herding Homing Infanticide Kin Recognition Mate Guarding Migration Nepotism Nesting Parasite Avoidance Parental Care Playing Predator-Prey Interactions Roosting Scent-Marking Sex Change Schooling Symbiotic Maintenance Territoriality Thermoregulation Etc…