Animal Behavior

1. Animal Behavior UNIT 10

2. Introduction • Humans have always studied animal behavior • Knowledge of animal behavior = human survival • For example, understanding behavior of animals hunted for food • Behavioral ecology – Studies how animal behavior is controlled and how it develops, evolves, and contributes to survival and reproductive success • For example, does play serve a developmental function? • How does migration contribute to reproductive success • An organism’s behavior is tied to survival & successful reproduction

3. Introduction (Page 2) • Ethology – Study of behavior & its relationship to its evolutionary origins • The study of how animals behave, especially in their native habitat • 3 Important Ethologists: • Karl von Frisch – Honeybee communication & waggle dance • Niko Tinbergen – Fixed action pattern • Konrad Lorenz - imprinting

4. 2 Levels of Behavioral Studies • Proximate causes of behavior • “How” questions • Include the effects of heredity on behavior, genetic-environmental interactions • Ultimate causes of behavior • “Why” questions • Studies of the origin of behavior • Utility of behavior in terms of reproductive success

5. Behavior, what is it? • Is it part of an organism’s phenotype or genotype? • Are hormonal secretions considered behavior? • Behavior is…

6. Fixed Action Pattern (FAP) • Commonly called innate behavior • Highly stereotypic behavior • Triggered by a sign stimuli (external stimulus) • When stimuli are exchanged between members of the same species, the stimuli are called releasers • Once begun, the behavior will continue to completion • Example: Stickleback fish • Sign stimulus: red underbelly (only males have red underbelly) in another male’s territory • Behavior triggered: Male attacks red-bellied stickleback fish or model

7. Stickleback Fish Which models will produce an aggressive response?

8. Learning • Def – sophisticated process in which the responses of the organism are modified as a result of experience • Def 2 – modification of behavior based on specific experience • Capacity to learn can be tied to • Length of life span • Animals with a short life span (eg Drosophila) have no time to learn, so these species rely on FAP behaviors • Complexity of the brain • Dolphins – more convolutions in the brain than any other species, so an increased reliance on learned behavior

9. Habituation • One of the simplest forms of learning • Def – loss of responsiveness to stimuli that convey little or no influence • Example: Cry-Wolf effect • Although animal may recognize an alarm call for predators • But there will be no continued response if the alarm call is not followed by an actual attack • Example 2: • If hydra is in a container, and the side is tapped = recoiling • If no harm is encountered after repeated tappings, the hydra will ignore the tapping – it has habituated to the stimulus

10. Associative Learning • Def – Type of learning where a stimulus is associated with another through experience • 2 Types of Associative Learning 1. Classical Conditioning – Ivan Pavlov -- Pavlov rang bell whenever dog was fed -- Soon even if no food was present, dog salivated when bell was rung -- Dog was conditioned to associate bell sound with food 2. Operant Conditioning – (trial and error learning) -- An animal learn to associate one of its behaviors with a reward or punishment -- Animal then repeats (rewarded) or avoids (punishment) the behavior

11. Operant Conditioning • B.F. Skinner (1930’s) • NOT Principal Skinner from “The Simpsons”  • Rat placed in a cage that contained a lever than when depressed = food pellet • At first, rat depressed by accident = food by accident • Soon, rat associated lever depressing with food appearance

12. Examples of Operant Conditioning

13. Imprinting • Def – Learning that occurs during a sensitive or critical period in the early life of an individual • Irreversible • Example: Konrad Lorenz & Geese hatchlings • Example of Imprinting: geese hatchlings closely follow their mother • Mother-offspring bonding in animals is crucial to safety & development of the offspring • Geese hatchlings follow the first thing they see that moves • Lorenz ensured that he was the first moving organism seen by the hatchlings • Hence, the geese hatchlings had imprinted on Lorenz • Wherever he went, the hatchlings followed

14. Imprinting (Page 2)

15. Questions 1. The Stickleback fish is an example of … 2. What are the 2 types of associative learning? 3. Which type of behavior is unlearned? 4. What type of learning allows an organism to ignore a particular stimulus? 5. Lorenz attempted to mimic what learning type?

16. Examples • Give an example, NOT from the notes, of: 1. Imprinting 2. Operant Conditioning (trial and error) 3. Habituation 4. Classical Conditioning 5. Fixed Action Pattern (FAP)

17. Social Behavior • Def - Any kind of interaction among two of more animals, usually of the same species • Relatively new field of study • 5 Social Behaviors to focus on: 1. Cooperation 2. Agonistic 3. Dominance Hierarchy 4. Territoriality 5. Altruism

18. Cooperation • Enables individuals to carry out a behavior performed more successfully by a group than individuals • Hunting in a pack – enables a number of individuals to take down a larger prey than any individual would be capable of • Example:

19. Agonistic Behavior • Aggressive behavior • Threats or actual combat to settle disputes among individuals • Access to mating, food, or shelter • Usually involves ritualistic or symbolic behavior, instead of actual combat • Dogs will bear teeth to try to scare the opponent • Loser will display submissive behavior (putting tail between their legs and running away • Once a dispute has been settled by agonistic behavior, future encounters will not (usually) involve further agonistic behavior

20. Examples of Agonistic Behavior

21. Dominance Hierarchy • Pecking Order behavior • Dictates social position an animal has in a culture • Alpha male & female in a population • Beta is next in line in social position • Alpha is assured of first choice of any resource • Food after a kill • Best territory • Most fit mate

22. Territoriality • Territory – area an organism defends & from which other members of the community are excluded • Territories are established & defended through agonistic behaviors • Territory is important for capturing food, mating opportunities, and rearing young • Size of territory is highly variable due to resources available, and function of the territory

23. Mating Systems 1. Promiscuous • No strong pair bonds • 2. Monogamous • 1-male & 1-female • 3. Polygamous • 1 individual mates with several others

24. Inclusive Fitness • Def – total effect an individual has on proliferating its genes BY 1. Producing its own offspring 2. Providing aid to other close relatives to produce offspring • This behavior is favored by natural selection since it enhances the the reproductive success of relatives • Called Kin Selection

25. Altruism • Does altruism exist? • Altuism = selflessness • Behavior that reduces an individual’s reproductive fitness, but increases the fitness of the group or family • For example: when a honeybee stings an intruder, while it may die, the colony is benefitted • Kin selection – Potential explanation for seemingly altruistic behavior • While the individual is sacrificed, the kin are selected as a result of performance of the behavior • So while the entire genome is not passed on, enough is passed on for the behavior (altruism) to be considered an evolutionary mechanism

26. Altruism • So does altruistic behavior exist? • Isn’t the honeybee’s offspring benefiting? • So the honeybee is not being selfless, but the behavior eventually results in selection for the organism’s offspring or kin • A more controversial case: A father in India decides that he will donate a kidney for $15,000. -- Is this altruistic behavior?