Behavioral Ecology Behavioral ecology emphasizes evolutionary hypotheses: Behavioral ecology is the research field that views behavior as an evolutionary adaptation to the natural ecological conditions of animals. We expect animals to behave in ways that maximize their fitness (this idea is valid only if genes influence behavior).

For Example: Bird Songs Wh y has natural selection favored a multi-song behavior? It may be advantageous for males attracting females - earlier mating

Proximate vs. Ultimate Behavior has both proximate and ultimate causes: 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. Ultimate questions address the evolutionary significance for a behavior and why natural selection favors this behavior.

Ethology

Innate Behaviors

Fixed Action Patterns (FAPs)

Sign Stimulus (Releaser)

Supra-Normal Sign Stimulus

Love: a FAP? (Harlow)

Imprinting Imprinting is the recognition, response, and attachment of young to a particular adult or object. Konrad Lorenz experimented with geese that spent the first hours of their life with him and after time responded to him as their “parent.” Lorenz isolated geese after hatching and found that they could no longer imprint on anything.

Imprinting Stimulus What is innate in these birds is the ability to respond to a parent figure; while the outside world provides the imprinting stimulus. The Sensitive Period is a limited phase in an individual animal’s development when learning particular behaviors can take place.

Learning Learning is the modification of behavior resulting from specific experiences

Maturation Maturation is the situation in which a behavior may improve because of ongoing developmental changes in neuromuscular systems, for example, flight in birds

Habituation Habituation is a kind of learning: Habituation 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).

Habituation

Classical Conditioning

Operant Conditioning This is called trial-and-error learning - an animal learns to associate one of its own behaviors with a reward or a punishment

Observational Learning

Cognition (Special/Insight Learning) Cognition is the ability of an animal’s nervous system to perceive, store, process, and use information gathered by sensory receptors

Play  Practice?  Exercise?  Socialization? (building/testing of bonds)  The “Excessive Energy of Youth?”

Learning across Phyla

Moving Behaviors  Kinesis: Activity only when stimulus is present, but activity is random (a.k.a., not moving only when happy)  Taxis: Movement up or down a gradient, i.e., towards something good or a way from something bad  Migration: Regular (e.g., annual) movement back and forth from place to place  Piloting: Directed movement from landmark to landmark; requires some form of map  Orientation: Directed movement consistently in a particular direction (e.g., employing compass)  Navigation: Directed movement employing some combination of piloting and orientation

Kinesis

Taxis

Migration

Piloting

Orientation

Navigation plus

Foraging

Cost-Benefit Analysis Costs or benefits Clutch size benefits: # of surviving young costs: risk of adult mortality payoff (cost-benefit)

Optimal Foraging Behavior “The optimal foraging theory states that natural selection will benefit animals that maximize their energy intake-to- expenditure ratio (“most bang for the buck”).”

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Optimal Diet Model Predictions from: Predators should specialize when more profitable prey is very abundant 2.There should never be a partial preference (predicted for an exact balance which is rare) 3.Predators should have broader diets in poor environments 4.Predators should ignore poor quality items irrespective of abundance

Specialist vs. Generalist To eat or not to eat! Basic strategies: Generalist –Broad diet, consume most of the prey they encounter –Spend little time searching –Diet includes low quality food Specialist –Narrow diet, consume specific prey –Only high quality food – Search time high

Sociobiology  Social Behaviors are interactions between conspecifics  Sociobiology is the application of evolutionary theory to our understanding of social behaviors  These behaviors include:  Fighting (and dominance hierarchies and maintaining territories)  Courting and Mating  Raising progeny  Cooperating (and Defecting)

Agonistic Behavior

Hierarchies & Territoriality  Dominance Hierarchies are found among chickens, wolves, humans, etc. The idea is to avoid fighting by knowing your place to avoid picking on conspecifics that you know have already whooped ya…  Territories are maintained in part as a means of reducing aggressive interactions An animal can avoid fighting by avoiding a conspecific’s territory  Fighting tends to occur mostly between conspecifics since same species are both better matched and more likely competitors (e.g., for food or mates)

Mating/Courtship Behavior

Differential Parental Investment  Females: Cost of egg, Cost of pregnancy (mammals), Cost lactating (mammals), Cost of raising (mostly mammals & birds)  Males: Sperm relatively cheap, Usually no pregnancy (sea horses exception), No lactation, Often no raising (some birds and humans exceptions), but…  Males: Paternity not assured, particularly given internal fertilization

Mating Systems

 Promiscuous: low likelihood of subsequent mating with same individual  Monogamous: high likelihood of subsequent mating with one individual  Polygamous: high likelihood of subsequent mating with more than one individual Polygyny: one male mates with several females Polyandry: one female mates with several males

Altruism/Cooperative Behavior Altruism is Cooperative Behavior in which the actor's Darwinian fitness is Reduced by the behavior

Defecting (not being altruistic)

Prisoner’s Dilemma Opponent’s Behavior  CooperationDefection Cooperation Reward for Mutual Cooperation Sucker’s Payoff Defection Temptation to Defect Punishment for Mutual Defection Darwinian Payoff Associated with Behavior: T > R > P > S Always Preferable to Defect Why Cooperate?

Prisoner’s Dilemma Examples  Aggressive Behavior: Cost = e.g., Owning / Carrying / Using Weapons; Payoff = Dominance over unarmed individuals (but 2 meeting without aggression is better than 2 with)  Driving SUV: Costs = Low fuel economy, Higher risk of fatal single-vehicle accidents; Payoff = Lower risk of fatality in two-vehicle accident (but 2 cars colliding preferable to 2 SUVs colliding)  Not Paying Taxes: Payoff = Enjoying benefits of government programs without paying for them; Cost = If everybody didn’t pay taxes there wouldn’t be any government programs (note: example n-player dilemma)

How can Altruism Persist? Altruism is cooperative behavior in which the actor's Darwinian fitness is reduced by the behavior How, then, can cooperative behavior persist?  Kin Selection (cooperating only with relatives)  Reciprocal Altruism (prisoner’s dilemma, TFT)  Group Selection (army of cooperators wins)  Punishment Avoidance (why we have police)

Coefficient of Relatedness

Reciprocal Altruism Opponent’s Behavior  CooperationDefection Cooperation Reward for Mutual Cooperation Sucker’s Payoff Defection Temptation to Defect Punishment for Mutual Defection Darwinian Payoff Associated with Behavior: T > R > P > S Therefore, R+R+R+R+R… > P+P+P+P+P…

Tit for Tat Opponent’s Behavior  CooperationDefection Cooperation Reward for Mutual Cooperation Sucker’s Payoff Defection Temptation to Defect Punishment for Mutual Defection Behavior: Lead with Cooperation then do whatever opponent does. Thus, S+P+P+P+P… with All D individuals but R+R+R+R+R… with All C & TFT individuals

Tit for Tat

Group Selection

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Acknowledgements Pearson Education, Inc. publishing as Benjamin Cummings

Piloting