Animal Behavior

1. Animal Behavior Chapter 45 Mader: Biology 8th Ed.

2. Outline • Genetic Basis • Nature versus Nurture • Learning • Female Choice • Male Competition • Dominance Hierarchy • Territoriality • Communicative Behavior • Sociobiology and Animal Behavior • Altruism versus Self-Interest Mader: Biology 8th Ed.

3. Genetic Basis • Two basic types of behavioral questions: • Mechanistic • Survival Value • Both recognize behavior, observable and coordinated responses to environmental stimuli, has at least a partial genetic basis. • Genes influence development of neural and hormonal mechanisms controlling behavior. Mader: Biology 8th Ed.

4. Nature or Nurture • Nature (inherited) versus nurture (environmental) questions have been, and are still, constantly debated. • Studies on identical twins can be used to determine extent of inherited behavior. • Genetically identical twins raised separately are sometimes remarkably similar. Mader: Biology 8th Ed.

5. 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. Mader: Biology 8th Ed.

6. Pecking Behavior of Laughing Gull Chicks Mader: Biology 8th Ed.

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. Mader: Biology 8th Ed.

8. The Phenomenon of Learning • Song Learning in Birds • Brain of a bird seems to be especially primed to respond to acoustical stimuli during a sensitive period. • Social experience appears to have an even stronger influence over development of singing. Mader: Biology 8th Ed.

9. Behavior Is Adaptive • Sexual selection refers to changes in females and males, often due to differential reproductive success, caused by mate choice and competition for mates. Mader: Biology 8th Ed.

10. 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. Mader: Biology 8th Ed.

11. Male Competition • Cost-benefit analyses have been conducted to determine if the benefit of access to mating is worth the cost of competition among males. • Positive effects (benefits) must outweigh negative effects (costs) if the behavior is to continue. Mader: Biology 8th Ed.

12. Dominance Hierarchy • Males and females have separate dominance hierarchies. • Higher-ranking individuals have greater access to 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. Mader: Biology 8th Ed.

13. Female Choice and Baboon Male Dominance Mader: Biology 8th Ed.

14. 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. • Less body fat, thus may be more likely to starve in bad times, and have shorter life span. Mader: Biology 8th Ed.

15. Competition Between Red Deer Stags Mader: Biology 8th Ed.

16. Animal Societies • Members of a society are organized in a cooperative manner that extends beyond sexual and parental behavior. • CommunicativeBehavior • Chemical • Pheromones designate chemical signals that are passed between members of the same species. Mader: Biology 8th Ed.

17. Communicative Behavior • 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. • Save energy by avoiding fighting. Mader: Biology 8th Ed.

18. 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 that indicates the distance and direction of a food source. Mader: Biology 8th Ed.

19. Communication Among Bees Mader: Biology 8th Ed.

20. Sociobiology and Animal Behavior • Sociobiology applies the principles of evolutionary biology to the study of behavior in animals. • Assume individuals derive more reproductive benefits than costs from living in a society. • Other advantages include predator avoidance, assistance in rearing offspring, and finding food. Mader: Biology 8th Ed.

21. Sociobiology and Animal Behavior • Societal Disadvantages • Crowding • Resource allocation. • Spread of disease. Mader: Biology 8th Ed.

22. Altruism versus Self-Interest • Altruism is behavior that involves a reduction in direct fitness that may be compensated by an increase in indirect fitness. • Inclusive Fitness includes both personal reproduction and reproduction of relatives. • Genetic relatedness may underlie many/most acts of apparent altruism. Mader: Biology 8th Ed.

23. 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. Mader: Biology 8th Ed.

24. Migratory Behavior in Blackcap Warblers Mader: Biology 8th Ed.

25. Feeding Behavior of Garter Snakes Mader: Biology 8th Ed.

26. Review • Genetic Basis • Nature versus Nurture • Learning • Female Choice • Male Competition • Dominance Hierarchy • Territoriality • Communicative Behavior • Sociobiology and Animal Behavior • Altruism versus Self-Interest Mader: Biology 8th Ed.

27. Mader: Biology 8th Ed.