Behavioral Ecology Chapter 51 BCOR 12 February 20

Behavioral Ecology Chapter 51 BCOR 12 February 20 and 23, 2009

Outline for 18 February, 2009 Chapter 51 - Behavioral Ecology I. General Introduction to Ecology II. Introduction to Behavior - what an animal does and how it does it. Proximate vs. ultimate causation Behavioral traits have both genetic and environmental components. Behavioral ecology emphasizes evolutionary explanations III. Learning A. Learning is experienced-based modification of behavior B. Imprinting: learning limited to a specific time period C. Bird song and the development of behavior D. Animals learn to associate one stimulus with another. E. Play

Ecology - the study of the interaction of organisms and their environment (including the biotic environment)

Ecology and evolutionary biology are closely related disciplines: an important cause of evolutionary change is the interaction of organisms with their environment.

Outline for 18 February, 2009 Chapter 51 - Behavioral Ecology I. General Introduction to Ecology II. Introduction to Behavior - what an animal does and how it does it. Proximate vs. ultimate causation Behavioral traits have both genetic and environmental components. Behavioral ecology emphasizes evolutionary explanations III. Learning A. Learning is experienced-based modification of behavior B. Imprinting: learning limited to a specific time period C. Bird song and the development of behavior D. Animals learn to associate one stimulus with another. E. Play

Behavior: what an animal does and how it does it.

Proximate vs. Ultimate Causation: Proximate explanations are mechanistic ones. Ultimate explanations address the evolutionary significance of a behavior.

Q. Why do Magnolia warblers build their nests in the springtime? Proximate explanation: increasing day length triggers nesting behavior Magnolia warbler Ultimate explanation: Magnolia warblers who nest in the springtime leave more offspring than those who nest later in the year.

Tucking behavior in lovebirds demonstrates that behavior has both a genetic and an environmental component. Inference: approach to nest building is genetically determined. Inference: innate behavior can be modified by learning.

Innate behaviors are developmentally fixed.

Behavioral ecology emphasizes evolutionary explanations: an animal showing optimal behavior will maximize its fitness.

Evolutionary explanations are testable! Example: cost/benefit analysis of foraging behavior in crows. Optimal foraging theory views behavior as a compromise between feeding costs and feeding benefits.

Optimal foraging behavior in crows Height of drop (meters) Mean no. of drops required Height X no. of drops 2 55 110 3 13 39 5 6 30 7 5 35 15 4 60 (data based loosely upon Zach, 1979, Behaviour 68: 106 -117)

Outline for 18 February, 2009 Chapter 51 - Behavioral Ecology I. General Introduction to Ecology II. Introduction to Behavior - what an animal does and how it does it. Proximate vs. ultimate causation Behavioral traits have both genetic and environmental components. Behavioral ecology emphasizes evolutionary explanations III. Learning A. Learning is experienced-based modification of behavior B. Imprinting: learning limited to a specific time period C. Bird song and the development of behavior D. Animals learn to associate one stimulus with another. E. Play

Homework Problem Set #2 is due today! Remember your name, TA’s name, and lab section

Learning is experienced-based modification of behavior Vervet monkeys learn the correct use of alarm calls.

Konrad Lorenz and friends Imprinting is learning limited to a specific time period

Imprinting is distinguished by a sensitive period, a limited phase in an animal’s development during which the learning of a particular behavior can take place.

Associative learning - the ability to learn to associate one stimulus with another. • Classical conditioning - the association of an arbitrary stimulus with reward or punishment Ivan Pavlov in his laboratory

• Operant conditioning - the animal associates its own behavior with a positive or negative stimulus. B. F. Skinner

Blue jays and monarch butterflies: an example of operant conditioning.

Play may involve both the learning of necessary behaviors and exercise, to keep muscular and cardiovascular systems in good tone.

Outline for 23 February, 2009 Chapter 51 - Behavioral Ecology IV. Animal Cognition A. The study of cognition connects nervous system function with behavior B. Cognitive mechanisms and travel 1 a. Kinesis 1 b. Taxis 2. Use of landmarks 3. Cognitive maps Migration – butterflies, whales, birds How? Piloting Orientation Navigation

Outline for 23 February, 2009 Chapter 51 - Behavioral Ecology V. Social behavior and Sociobiology A. Sociobiology places social behavior in an evolutionary context B. Competitive Social Behaviors 1. Agonistic behavior 2. Dominance hierarchy 3. Territoriality C. Natural selection favors mating behavior that maximizes quality or quantity of partners 1. Courtship 2. Mating Systems D. Social interaction depends on diverse modes of communication 1. Animal signals and communication 2. Pheromones – moths 3. Honeybee dance E. Altruistic behavior and inclusive fitness 1. Altruism 2. Hamilton’s Rule and Kin Selection F. Sociobiology and Human Culture

Cognition – the ability of an animal’s nervous system to perceive, store, process, and use information gathered through its senses. Dr. Bernd Heinrich UVM Biology Dept. More smart corvids: http: //www. youtube. com/ watch? v=BGPGknpq 3 e 0

Cognitive Mechanisms and Travel

Migration

The mechanisms animals use for “finding their way” varies with the kind of animal and the spatial scale of the trip. Sowbugs use kinesis, an automatic change in activity in response to a stimulus. Planaria use taxis, a more or less automatic movement towards or away from some stimulus.

Migrating juvenile starlings use orientation - compass direction whereas experienced adults use navigation.

V. Social behavior and Sociobiology A. Sociobiology places social behavior in an evolutionary context B. Competitive Social Behaviors 1. Agonistic behavior 2. Dominance hierarchy 3. Territoriality C. Natural selection favors mating behavior that maximizes quality or quantity of partners 1. Courtship 2. Mating Systems D. Social interaction depends on diverse modes of communication 1. Animal signals and communication 2. Pheromones – moths 3. Honeybee dance E. Altruistic behavior and inclusive fitness 1. Altruism 2. Hamilton’s Rule and Kin Selection F. Sociobiology and Human Culture

Competitive Social Behaviors

Agonistic behavior – a contest to determine which competitor gains access to resources (food, mates, etc. )

Chimps, which live in social groups often show reconciliation behavior following a conflict.

Dominance hierarchy - a linear social organization within a group. The top ranked animals are assured access to resources. Low ranked animals do not waste energy or risk harm in combat.

Territory – a territory is an area an animal defends, keeping out members of their own kind (species). Territories are used for feeding, mating, and rearing young. Redwing blackbird

Territorial boundaries are proclaimed by scent, song, howling, or other vocalization.

Evolution of Mating Behavior Campbell, ed. 8, pp. 1134 -1138 Chapter 51 slides 38 -44

Mating behavior • Seeking/attracting, choosing among and competing for mates • Product of sexual selection

Mating systems • Promiscuous: – No strong pair-bonds • Monogamy • Polygamy – Polyandry and Polygyny What determines whether an animal will be monogamous or polygamous?

Needs of young important factor constraining evolution of mating systems Parental investment Time and energy an individual expends to produce and nurture offspring When young require a large investment in parental care, males may maximize their fitness by helping one mate rather than by going off to seek additional mates

Certainty of paternity also important in determining mating behavior and parental care Males may invest more heavily in parental care when they are more certain of paternity (Increased fitness only if they are your genes that are being passed on. )

Sexual Selection and Mate Choice • Sexual dimorphism results from sexual selection, a form of natural selection in which differences in reproductive success among individuals are a consequence of differences in mating success. Intersexual selection - members of one sex choose mates on the basis of particular characteristics of the other sex—such as courtship songs

Intrasexual selection - competition among members of one sex for mates Lekking behavior in male black grouse, Finland

Competition for mates Male competition for mates is a source of intrasexual selection that can reduce variation in males Agonistic behavior – behavior that determines which competitors gain access to mates

Be prepared to answer questions such as these: The evolution of mating systems is most likely affected by: A) population size. B) care required by young. C) certainty of paternity. D) B and C only E) A, B , and C Fred and Joe, two unrelated, mature male gorillas, encounter one another. Fred is courting a female. Fred grunts as Joe comes near. As Joe continues to advance, Fred begins drumming (pounding his chest) and bares his teeth. Joe then rolls on the ground on his back, gets up, and quickly leaves. This behavioral pattern is repeated several times during the mating season. Choose the most specific behavior described by this example. A) agonistic behavior B) territorial behavior C) learned behavior D) social behavior E) fixed action pattern

Animal Communication Social behavior depends on effective communication.

Signal – a behavior that causes a change in the behavior of another animal.

Pheromone - a volatile chemical produced by one animal that elicits a change in another’s behavior.

Communication among honeybees promotes foraging efficiency. Watch the waggle dance

Altruism and Kin Selection

Altruism - behavior that decreases the individual fitness of the practitioner and increases the fitness of the recipient.

Inclusive fitness - The total effect that an individual has on proliferating its genes by producing its own offspring and by providing aid that enables other close relatives to increase the production of their offspring. My inclusive fitness = my offspring + the offspring my close relatives are able to rear because of the support I provided.

Hamilton’s Rule and Kin Selection Three key variables in an act of altruism: • B – benefit to recipient • C – cost to altruist • r – coefficient of relatedness r = 0. 5 The coefficient of relatedness (r) between two individuals = the percentage of genes that they share by common descent. Hamilton’s rule: Natural selection will favor altruism if r. B > C

Kin selection and altruism in Belding’s ground squirrel: nearly all alarm call are given by females. Females are more closely related to one another than the males are. A Belding’s ground squirrel sounds the alarm.

“Over our recent evolutionary history, we have built up a diversity of structured societies with governments, laws, cultural values, and religions that define what is acceptable behavior and what is not, even when unacceptable behavior might enhance an individual’s Darwinian fitness. Perhaps it is our social and cultural institutions that make us truly unique and that provide the only feature in which there is no continuum between humans and animals. ” - Neil Campbell