Animal Behavior Chapter 45

Animal Behavior 2Outline 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

Animal Behavior 3 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.

Animal Behavior 4 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 Associative Learning A change in behavior that involves an association between two events is termed associative learning. Classical Conditioning In classical conditioning, the paired simultaneous presentation of two different types of stimuli causes an animal to form an association between them. In classical conditioning, the paired simultaneous presentation of two different types of stimuli causes an animal to form an association between them. This suggests that an organism can be trained (conditioned) to associate any response with any stimulus. This suggests that an organism can be trained (conditioned) to associate any response with any stimulus. Unconditioned responses are those that occur naturally; conditioned responses are those that are learned. Unconditioned responses are those that occur naturally; conditioned responses are those that are learned. 5

Animal Behavior 6 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 7 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

Animal Behavior Orientation and Migratory Behavior Migration is long-distance travel from one location to another. Loggerhead sea turtles hatch on a Florida beach and then travel across the Atlantic Ocean to the Mediterranean. Loggerhead sea turtles hatch on a Florida beach and then travel across the Atlantic Ocean to the Mediterranean. Monarch butterflies fly from North America to Mexico so they can continue breeding. Monarch butterflies fly from North America to Mexico so they can continue breeding. Migration requires orientation, which is the ability to travel in a particular direction, such as south in the winter and north in the spring. Many birds use the sun during the day or the stars at night to orientate themselves. Many birds use the sun during the day or the stars at night to orientate themselves. Experienced birds can navigate, or be able to change their direction in response to other environmental clues that tell them they are currently headed in the wrong direction. 10

Starling Migratory Experiment 11

Animal Behavior 12 Behavior Is Adaptive Sexual selection - Adaptive changes in females and males that lead to differential reproductive success

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 14 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

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

16 A Male Olive Baboon Displaying Full Threat

Animal Behavior 17Territoriality 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

18 Competition Between Male Red Deer

Animal Behavior 19 Animal Societies Society - a cooperative organization that extends beyond sexual and parental interests The principles of evolutionary biology can be applied to the study of social behavior in animals. It is based on a reproductive cost-benefit analysis of the value of living in a society. There are both benefits and costs to living in a social group. Only if the benefits, in terms of reproductive success, outweigh the disadvantages will societies evolve.

Animal Behavior Advantages Advantages to living in a social group might include help to avoid predators, to raise young, and to find food. A group of impalas has more eyes to see approaching predators, etc. A group of impalas has more eyes to see approaching predators, etc. Many fish moving rapidly in a school can distract a predator. Many fish moving rapidly in a school can distract a predator. The trumpet manucode (a bird) pair bonds for life; both sexes are needed to raise the young. The trumpet manucode (a bird) pair bonds for life; both sexes are needed to raise the young. Weaver birds form giant colonies to protect them from predators. Weaver birds form giant colonies to protect them from predators. Primate members signal the group when they find a bountiful fruit tree. Primate members signal the group when they find a bountiful fruit tree. Lions working together can capture larger prey, such as a zebra or buffalo. Lions working together can capture larger prey, such as a zebra or buffalo. 20

Animal Behavior Disadvantages There are also disadvantages to living in a social group. Disagreements occur between members over the best feeding places and resting sites. Disagreements occur between members over the best feeding places and resting sites. Among red deer, subordinate females are at a disadvantage in producing more prolific sons. Among red deer, subordinate females are at a disadvantage in producing more prolific sons. Primate grooming may be necessary to keep them healthy since parasites spread easily in groups. Primate grooming may be necessary to keep them healthy since parasites spread easily in groups. 21

22 The Queen Ant

Animal Behavior 23 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

24 Inclusive Fitness

Animal Behavior 25 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

26 Use of a Pheromone

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

28 Grooming Among Baboons

29 Communication Among Bees

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 success  Predator avoidance  Assistance in rearing offspring  Finding food

Animal Behavior 31 Sociobiology and Animal Behavior Societal Disadvantages  Crowding ­Resource allocation ­Spread of disease

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

Animal Behavior Ending Slide Chapter 45