UNIT 10 Animal Behavior

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

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

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

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

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

Stickleback Fish Which models will produce an aggressive response?

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

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

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

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

Examples of Operant Conditioning

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

Imprinting (Page 2)

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?

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)

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

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:

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

Examples of Agonistic Behavior

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

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

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

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

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

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, Is this altruistic behavior?