Behavioral Biology Chapter 54

2 Approaches Behavior: the way an animal responds to stimulus in its environment Proximate causation:“how” of behavior –Hormones –Impulse of nerve signal Ultimate causation: “why” of behavior -influence on reproductive success or survival

3 Innate behavior: instinctive, no learning –Preset –Genetic Example: goose; Egg retrieval behavior is triggered by a sign stimulus. Innate releasing mechanism or fixed action pattern

4 Male stickleback fish will attack anything with a red underside –Does not need to be a fish What is sign stimulus? What is the fixed action pattern?

5 Human twin study identical genetically 50 sets, twins raised separately –Similarity in personality, temperament, leisure time activities Qenetics plays a role in determining behavior even in humans Behavioral Genetics

6 fosB present: mother cares for her young fosB absent: young are ignored and eventually die Behavioral Genetics

7 Learning Learning: altered behavior as a result of experiences Nonassociative learning: no association is formed between two stimuli or between a stimulus and response –Habituation: –learn not to respond to repeated occurrences of stimulus

8 Associative learning: association between two stimuli or between a stimulus and a response –Conditioned behavior through association Learning Associative learning is involved in predator-prey interactions: after being stung the toad learns not to eat bumblebees.

9 Classical conditioning: the paired presentation of two different kinds of stimuli with an association formed between them –Pavlovian conditioning stimulus: meat response: salivating Conditioned stimulus: bell ringing Conditioned response: After time, the dog salivates with only the ringing of the bell

10 Operant conditioning: animal learns to associate its behavior response with a reward or punishment –B.F. Skinner –Trial and error learning Learning

11 Instinct and learning –Innate predispositions toward forming certain associations –Pigeons can learn to associate food with colors, but not with sound –Learning is possible only within the boundaries set by instinct –In nature, adaptation by learning is important to survival Learning

12 Clark’s nutcracker can remember the locations of up to 2000 seed caches months after hiding them Uses spatial memory Learning

13 Development of Behavior Parent-offspring interactions influence cognition and behavior Imprinting: formation of social attachment to other individuals or develop preferences that will influence behavior later in life Filial imprinting: attachment between parents and offspring –Konrad Lorenz

14 Goslings follow Konrad Lorenz as if he were their mother 1973 Nobel Prize Development of Behavior

15 Instinct and learning may interact as behavior develops –White-crowned sparrow males sing species-specific courtship song during mating –Genetic template: innate program to learn the appropriate song –Can not learn the song unless they hear it at a critical period in development Development of Behavior

16 a.Exposed to own species song during development b.Not exposed to song Development of Behavior

17 Cuckoos are raised by a different species Learn their own song: innate Development of Behavior

18 Animal Cognition

19 Orientation and Migratory Behavior Orientation: goal-oriented movements –Taxis: movement toward or away from a stimulus –Kineses: more or less active when stimulus intensity increases

Orientation and Migratory Behavior

21 Migrating animals must be capable of orientation and navigation Navigation: the ability to set or adjust a bearing –Sun and stars –Earth’s magnetic field Orientation and Migratory Behavior

22 Communication Communication can play a key role in behaviors –Among members of the same species –Between species Long-distance communication –Pheromones: chemical messengers –Acoustic signals –Light signals: firefly

23 In group living –Guards: set off an alarm call –Social insects produce pheromones that trigger attack behavior –Ants deposit trail pheromones between nest and food source Communication

24 The waggle dance of honeybees Communication

25 Vocabulary to communicate identity of specific predators Communication

26 Behavioral Ecology Niko Tinbergen BEHAVIORAL ECOLOGY: –Development –Physiological basis –Function: including evolutionary significance

27 Optimal foraging theory: natural selection favors individuals whose foraging behavior is energetically efficient Behavioral Ecology

28 Territorial behavior secures resources Birds sing or display to signal their territory; energetically costly Benefit: increased food intake Behavioral Ecology

29 Mate choice: Females evaluate a male’s quality –Females are usually responsible for gestation and lactation –higher investment –Eggs larger than sperm Sexual Selection

30 Male seahorses brood and care for the young Females compete for males when males are choosey Sexual Selection

31 Sexual selection involves both: –Intrasexual selection: interactions between members of one sex –Intersexual selection: interactions between members of opposite sex (mate choice) Sexual selection leads to the evolution of structures used in combat with other males. Ex. Antlers, horns Sexual Selection

32 Intrasexual selection Males –compete for opportunity to mate –defend their territory & females –mate with many females: Sexual Selection

33 Altruism: the performance of an action that benefits another individual at a cost to the actor Altruism Reciprocal altruism: Partnerships in which mutual exchanges of altruistic acts occur because they benefit both participants –Cheaters are discriminated against –Vampire bats Share blood meal

34 Kin selection: direct genetic advantage; selection favors relatives Altruism Kin selection in white-fronted bee-eater

35 Haplodiploidy and Hymenopteran social evolution Bee hive: eusocial society –single queen lays eggs Queen shares 50% of alleles with offspring –Cooperative care of the –Brood Altruism

36 Advantages –Kin selection: greater odds of alleles surviving in the gene pool –Greater protection from predators –Increase feeding success Social Systems