Animal Behavior

Genetic Basis Behavior - observable and coordinated responses to environmental stimuli Nature (inherited) versus Nurture (environmental) questions are still debated

Nest Building Behavior in Lovebirds Studies with lovebirds (Fischer & Peach-faced) support the hypothesis that behavior has a genetic basis.

Feeding Behavior in Garter Snakes A genetic difference between the two populations of snakes results in a physiological difference

Genetic Basis Nature vs Nurture 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.

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

Pecking Behavior in Laughing Gulls

The Phenomenon of Learning Operant Conditioning Gradual strengthening of stimulus-response corrections Trick-training in birds

The Phenomenon of Learning Imprinting Imitate behavior observed during sensitive period Goslings follow any moving object after birth

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

Classical Conditioning

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

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

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 - behavior is evolutionarily stable;behavior will survive or increase If no - behavior is evolutionarily Unstable; behavior will decrease or disappear

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 Dominance Hierarchy A Male Olive Baboon Displaying Full Threat

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

Adaptive Mating Behavior Evolution by Sexual Selection occurs when: females have the opportunity to select among potential mates and/or when males compete among themselves for access to reproductive females

Competition Between Male Red Deer

Animal Societies Society - a cooperative organization that extends beyond sexual and parental interests

Sociobiology and Animal Behavior 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

Altruism versus Self-Interest Behavior that involves a reduction in direct fitness Loss may be compensated by an increase in indirect fitness

Inclusive Fitness Inclusive Fitness includes: Reproductive fitness of self, and Reproductive fitness of relatives Genetic relatedness may underlie many/most acts of apparent altruism

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

Communicative Behavior Chemical Auditory Visual Tactile

Communicative Behavior Chemical Pheromones designate chemical signals that are passed between members of the same species

Use of a Pheromone

Communicative Behavior Auditory Faster than chemical communication Can be modified by loudness, pattern, repetition, and duration

A Chimpanzee With a Researcher

Communicative Behavior Visual Used by species active during the day Contests between males make use of threat postures Saves energy by avoiding fighting

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

Communication Among Bees Tactile