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Chapter 45 Animal Behavior Animal Behavior Outline Nature versus Nurture: Genetic Influences Nature versus Nurture: Environmental Influences Learning Adaptive Mating Behavior Female Choice Male Competition Dominance Hierarchy Territoriality Animal Communication Sociobiology and Animal Behavior Altruism versus Self-Interest 2 Animal Behavior Genetic Basis Behavior - observable and coordinated responses to environmental stimuli Nature (inherited) versus nurture (environmental) questions are still debated Genes influence development of neural and hormonal mechanisms controlling behavior Studies on identical twins separated at birth - Can be used to determine extent of inherited behavior - Sometimes remarkably similar in preferences, taste, personality tests, etc. 3 Nest Building Behavior in Lovebirds 4 Feeding Behavior in Garter Snakes 5 Animal Behavior 6 Behavior Undergoes Development Some behaviors seem to be stereotyped Fixed Action Patterns (FAP’s) - Originally assumed to be elicited by a sign stimulus - Increasingly thought to develop after practice Animal Behavior 7 The Phenomenon of Learning Operant Conditioning Gradual strengthening of stimulus-response corrections Trick-training in birds Imprinting Imitate behavior observed during sensitive period Goslings follow any moving object after birth Animal Behavior The Phenomenon of Learning Song Learning in Birds Avian brain is especially sensitive to acoustical stimuli during a sensitive period Social experience appears to have an even stronger influence over development of singing 8 Pecking Behavior in Laughing Gulls 9 Classical Conditioning 10 Animal Behavior 11 Behavior Is Adaptive Sexual selection - Adaptive changes in females and males that lead to differential reproductive success Raggiana Bird of Paradise 12 Animal Behavior 13 Female Choice Courtship displays help males and females recognize each other for successful mating Good Genes Hypothesis - Females benefit from selective choice by securing sperm with good genes Run-Away Hypothesis - Females choose mates on the basis of traits that make them attractive to females Animal Behavior Male Competition Is access to mating is worth the cost of competition among males Question is studied by cost-benefit analyses Do positive effects (benefits) outweigh negative effects (costs)? - If yes The behavior is evolutionarily stable The behavior will survive or increase - If no The behavior is evolutionarily UNstable The behavior will decrease or disappear 14 Animal Behavior 15 Dominance Hierarchy Males and females have separate dominance hierarchies Higher-ranking individuals have greater access to essential resources Baboons form temporary consort pairs with females - Males may monopolize estrous females - Or may assist females or form friendship groups to secure future matings A Male Olive Baboon Displaying Full Threat 16 Animal Behavior 17 Territoriality Territoriality is protecting an area against other individuals Red Deer Stags (males) compete for groups of hinds (females) Hinds only mate with one stag Harem Master must be large and powerful to fight off challengers - Means less body fat - May be more likely to starve in bad times, and have shorter life expectancy Competition Between Male Red Deer 18 King Hussein and Family 19 Animal Behavior 20 Animal Societies Society - a cooperative organization that extends beyond sexual and parental interests The Queen Ant 21 Animal Behavior 22 Altruism versus Self-Interest Altruism Behavior that involves a reduction in direct fitness Loss may be compensated by an increase in indirect fitness Inclusive fitness includes Reproductive fitness of self, and Reproductive fitness of relatives Genetic relatedness may underlie many/most acts of apparent altruism Inclusive Fitness 23 Animal Behavior 24 Communicative Behavior Communicative Behavior Chemical - Pheromones designate chemical signals that are passed between members of the same species Auditory Faster than chemical communication Can be modified by loudness, pattern, repetition, and duration Visual Used by species active during the day - Contests between males make use of threat postures - Saves energy by avoiding fighting Use of a Pheromone 25 A Chimpanzee With a Researcher 26 Animal Behavior 27 Communicative Behavior Tactile Occurs when one animal touches another - Gull chicks peck at the parent’s beak in order to induce the parent to feed them - Foraging honeybees Return to the hive and perform a waggle dance Indicates the distance and direction of a food source Grooming Among Baboons 28 Communication Among Bees 29 Animal Behavior 30 Sociobiology and Animal Behavior Sociobiology Applies the principles of evolutionary biology to the study of behavior in animals Assumes individuals derive benefits from living in a society that outweigh costs - Advantages include reproductive Predator avoidance Assistance Finding success in rearing offspring food Animal Behavior Sociobiology and Animal Behavior Societal Disadvantages Crowding - Resource allocation - Spread of disease 31 Animal Behavior 32 Nest Helpers Green Wood-hoopoes One breeding pair per flock - Other sexually mature members may help feed and protect fledglings and protect the home territory - Helper is contributing to survival of its own kin - Helper is more likely than nonhelper to inherit parental territory