1. Zool 4312/5312: Animal Behavior Introduction Kenneth A Schmidt Texas Tech University Dept Biological Sciences

2. Decision-making

3. QHR = P + MOC + C ____  F  e Harvest rate Predation cost Missed opportunity cost Metabolic cost P F e P F e Hazardous Duty Pay Predation risk and navigating a risky environment

4. Using cues and con or heterospecifics to estimate predation risk

6. Mate choice/fidelity and mating systems in veeries

7. Why does the Veery sing? Tinbergen’s 4 Why’s and causation in animal behavior “Why does the animal do that?” (1) In terms of the function or adaptive value – they sing to attract mates for breeding

8. Without implying that the animal is aware of its effects or actions - evolution produces machines that successfully reproduce themselves “How is (or might) the behavior (be) adaptive?” in other words, we can substitute... Why does the Veery sing?

9. (2) In terms of the Causation – the processes inside (endogenous) or outside (exogenous) that produces the observed behavior. They sing b/c increasing day length triggers hormonal changes in the body or b/c of the way air flows across the syrinx and creates membrane vibrations... All answers are right and it is pointless to argue about which is correct, rather it is important to distinguish between the different kinds of answers (3) In terms of Development – they sing b/c they learned the song from parents or neighbors (4) In terms of the Evolutionary origins of the behavior – the evolution of complex songs arose from simpler songs of ancestral thrushes.

10. Animal Behavior Proximate Perspective/Causation Ultimate Perspective/Causation Function or adaptive value Proximate Causation physiology environmental control Cognition – analyzing, using, acquiring information – e.g., day length Behavioral Ecology – defined as the attempt to predict behavior from 1 st principles of evolutionary biology that consider the consequences of behavior on fitness (adaptive value) **

11. Lions breed throughout the year, but females within a pride come into estrus synchronously – Prox: Chemical cues (pheromones) stimulate the beginning of estrus Ultim: Cubs born synchronously survive better: communal suckling of young; stronger male coalitions

12. Females come into heat for 2-4 days over which 600+ copulations may occur Prox: There is a high probability of ovulation failure and abortion Ultim: Only 1:3000 copulations will produce a surviving cub & devalued copulations reduce the benefit of fighting for access to the female; increase paternity uncertainty to prevent males from killing young not fathered

13. After a pride takeover by new males, they will attempt to kill all the cubs under ~18 mo. Prox: Unfamiliar odor of cubs induces male to commit infanticide (Bruce Effect) Ultim: Induces females to come into estrus quickly; males do not invest valuable resources raising cubs which are not their own

14. Another example: Alternative male phenotypic strategies in tree lizards

15. 9 recognized color-morphs 1 to 5 morph types per individual population Fixed morph types with a genetic basis – in the lab, broods are a mix of Orange and Orange-blue phenotypes in the same ratio as seen in the wild Several behavioral correlates with dewlap color Tree Lizard Urosaurus ornatus

16. dewlap display 10 70 60 50 40 30 20 approachface-offchargebite Differences in aggressiveness of free-living males to a tethered random color morph male intruder increasing aggressiveness Orange Orange-blue

17. OrangeOrange-blue Small home range (20m 2 ) Nomadic during stressful times (e.g., drought) Greater body mass; long and lean Large ranges (85m 2 ) Sedentary, never nomadic Smaller body mass, but more massive at a given body length What do these represent ?

18. OrangeOrange-blue Small home range (20m 2 ) Nomadic during stressful times (e.g., drought) Greater body mass; long and lean Large ranges (85m 2 ) Sedentary, never nomadic Smaller body mass, but more massive at a given body length Alternative Male Reproductive Strategies What do these represent ?

19. immature male female hormones immaturenonbreeding breeding Fixed strategies Plastic responses A model for a hormonal mechanism of sexual differentiation

20. immature territorial sneaker hormones immatureterritorial nomadic Fixed strategies Plastic responses Orange Orange-blue Orange

21. 25 100 75 50 Percentage of males controlProgesterone Progesterone determines male’s reproductive strategy (1)Progesterone levels evenly split between 50% males 0.1-1 ng/ml 50% males 10-100 ng/ml (2) Male’s strategy is affected by progesterone injections at hatch day (Moore 1998)

22. Aggressive and territorial; mate with all females in their territory Non-aggressive, mildly territorial in good yrs; mate by sneaking into territories to “steal” copulations

23. Summary: (1) Every question in Animal Behavior has a (actually several) proximal explanations that focus on the mechanisms of how the behavior and comes about; and one ultimate explanation based on function/adaptive value (2) Although we focused on hormones, hormones are linked to the environmental conditions, which provide a proximal stimulus, and they must have underlying genetic control – which itself is under molecular control... (3) There is a tight fit between form (proximal mechanisms) and function (why has the trait evolved)