Behavioral Ecology

1. Behavioral Ecology

2. Behavior is what an animal does and how it does it

3. Proximate questions are mechanistic, concerned with the environmental stimuli that trigger a behavior, as well as the genetic and physiological mechanisms underlying a behavioral act. Question: Why do Cliff Swallows build and repair nests in spring? Lengthening light exposure produces neural & hormonal changes that induce behavior

4. Question: Why do Cliff Swallows reproduce in the spring? At that time, parents can find ample food for rapidly growing offspring, providing advantage in reproductive success compared to birds that breed in other seasons. • Ultimate questions address the evolutionary significance for a behavior and why natural selection favors this behavior.

5. Ethology is the study of how animals behave in their natural habitat. Karl von Frisch, Konrad Lorenz, and Niko Tinbergen are three individuals who were foremost in the initial stages of this field.

6. Innate behavior is developmentally fixed • These behaviors are due to genetic programming. • The range of environmental differences among individuals does not appear to alter the behavior. • Examples: • *Fixed Action Patterns • *Directed Movements • - Kinesis and Taxis • *Migration • *Animal Signals and • Communication • - Chemical and Auditory

7. Fixed action pattern (FAP) • A sequence of unlearned behavioral acts that is essentially unchangeable and usually carried to completion once initiated. • The FAP is triggered by an external sensory stimulus known as a sign stimulus (stimuli are usually obvious). • The FAP usually occurs in a series of actions the same way every time. • Many animals tend to use a relatively small subset of the sensory information available to them and behave stereotypically.

10. Directed Movements • Kinesis is a change in activity rate in response to a stimulus. • For example, sowbugs are more active in dry areas and less active in humid areas.

11. Colorado Potato Beetles increase rate of circular vs linear movement in response to food

12. Directed Movements • Taxis is an automatic, oriented movement to or away from a stimulus. • For example, phototaxis, chemotaxis, and rheotaxis.

13. Migration • Migration is the regular movement of animals over relatively long distances. • Piloting: an animal moves from one familiar landmark to another until it reaches its destination. • Navigationis the most complex, and involves determining one’s present location relative to other locations in addition to detecting compass directions. • Cues for these behaviors include the earth’s magnetic field, the sun, and the stars.

18. http://www.youtube.com/watch?v=If_WoppsSGM&feature=related

19. Animal Signaling and Communication • A signal is a behavior that causes a change in the behavior of another animal. • The transmission of, reception of, and response to signals make up communication. • Examples include the following: • Displays such as singing, and howling. • Information can be transmitted in other ways, such as chemical, tactile, electrical.

20. Pheromones are chemicals released by an individual that bring about mating and other behaviors. • Examples – Ants, Bees, Scent-marking in Canids and Felids

21. The Dance of theHoneybee. Bees forage to maximize their food intake. If an individual finds a good food source, it will communicatethe location to others in the hive through an elaborate dance.

23. Genes even influence Mating System! • Insertion of prairie vole V1a receptor gene (produces arginine-vasopressin, a neurotransmitter) induced monogamy in normally promiscuous mice!

24. Nature vs. Nurture NO longer appropriate framework • Behavior results from both genes AND environmental factors We are becomingly increasingly aware of how environmental factors can alter how our genes are expressed, spawning Epigenetics

25. Randy Jirtle, a geneticist in the Department of Radiation Oncology at Duke University . . . • Jirtle: We have recently demonstrated that exposure of pregnant mice to bisphenol A (BPA), a building block of polycarbonate plastics and epoxy resins used to make consumer items ranging from water bottles to dental sealants, significantly reduces DNA methylation in Avy mice (Dolinoy et al., Proc. Natl. Acad. Sci. USA 104: 13056-13061, 2007). This results in the birth of more yellow offspring, mice that become obese and have a higher incidence of diabetes and cancer as adults. Thus, there could be a connection between the increase in plastics in our environment and the rising incidence of obesity in humans. However, such an association will not be able to be demonstrated unequivocally until the expression and function of genes involved in human obesity are shown to be altered by BPA.

26. Imprinting • Type of behavior that involves BOTH learning and innate components and is generally irreversible • Sensitive period during development when certain behaviors are learned

27. Learning • Learning is the modification of behavior resulting from specific experiences. • The alarm calls of vervet monkeys provide an example of how animals improve their performance of behavior.

28. Habituation • This involves a loss of responsiveness to unimportant stimuli or stimuli that do not provide appropriate feedback. • For example, some animals stop responding to warning signals if signals are not followed by a predator attack (the “cry-wolf” effect).

29. Spatial Learning • Modification of behavior based on experience with spatial structure of environment • Example – Digger wasps relocating nests

30. Associative Learning • Associative learning is the ability of many animals to learn to associate one stimulus with another. • Examples: Classical conditioning, Operant conditioning

31. Operant Conditioning • Trial and error learning • Learning to associate behavior with reward or punishment

32. Cognition and Problem Solving • Cognition is the ability of ananimal’s nervous system toperceive, store, process, anduse information gatheredby sensory receptors.

34. Self-awareness – evidence for animal consciousness?

35. Salient Point:Natural selection favors behaviors that increase survival and reproductive success • Examples: • Optimal Foraging Behavior • Mating Behavior • Social Behaviors • -Agonistic, Dominance Hierarchies, Territoriality

36. Optimal Foraging Theory • Foraging is a compromise between the benefits of nutrition and the costs of obtaining food, such as energy expenditure and the risk of being eaten by a predator while foraging

37. Mating Systems • 1) Promiscuous: no strong bond pairs between males and females. • 2) Monogamous: one male mating with one female. • 3) Polygamous: an individual of one sex mating with several of the other sex. • -Polygyny is a specific example of polygamy, where a single male mates with many females. • -Polyandry occurs in some species where one female mates with several males.

38. Monogamous species often monomorphic! • Many bird species (~90%) monogamous as newly hatched birds require large, continuous food supply, that a single parent may not be able to provide • However field work is providing increasing evidence of extra-pair copulation among “monogamous” species

39. Among polygynous species males tend to be larger and highly ornamented (sexual dimorphism) • Males maximize reproductive success by seeking multiple mates

41. Agonistic behavior is a contest involving threats. • -Examples: Submissive behavior, Play behavior, Dominance hierarchies (Alpha, beta . . .) • -Ritual: the use of symbolic activity • -Generally, no harm is done

42. Territoriality is behavior where an individual defends a particular area, called the territory. • Territories are typically used for feeding, mating, and rearing young and are fixed in location. • Drawbacks are that territoriality uses a great deal of an individual’s energy.

43. What’s up with animal Altruism? • Most social behaviors are selfish, so how do we account for behaviors that help others? • Altruism is defined as behavior that might decrease individual fitness, but increase the fitness of others.

45. Inclusive Fitness • Inclusive fitness is defined as the affect an individual has on proliferating its own genes by reproducing and helping relatives raise offspring. • If related individuals help each other, they are in affect helping keep their own genes in the population. • The more closely related two individuals are, the greater the value of altruism.