Animal Behavior

Behavior is what an animal does and how it does it. Result of genetic and environmental factors Essential for survival and reproduction Subject of natural selection over time

Behavior can be simple or extremely complex. Bacterial cell “behaves” by moving toward a sugar source. Allows bacteria to live and reproduce. Animals with complex nervous systems receive and process large amounts or information and produce complex patterns of behavior.

Ethology is the study of Behavior Behavior can be explained in two different ways PROXIMATE CAUSATION answers the “what and how” questions. Proximate includes effects of heredity, environment, and sensory-motor mechanisms. ULTIMATE CAUSATION answers the “why” questions. Ultimate studies origin and evolution of behavior in terms of reproductive success.

Questions: Male songbird sings. Proximate cause asks how. Measure hormone levels. Examine neuron connections. Ultimate cause asks why. Evolutionary value. Defense of territory Attract females

Fig. 51-2

Founding fathers of Ethology Karl von Frisch, Konrad Lorenz and Niko Tinbergen won the Nobel Prize for their work in the study of innate behavior.

Innate Behavior Stereotyped behaviors that occur in the same way in different individuals of a species. Behavior pathways are structured in genetic blueprints. Behavior occurs the same way from the first time and throughout the entire life of the animal.

Fixed Action Patterns FAP is a sequence of unlearned acts that is largely unchangeable and usually carried to completion once initiated. A sign stimuli is a “signal” in the environment that triggers a FAP behavior.

Male stickleback fish have red bellies. Fig. 51-3 Male stickleback fish have red bellies. Female stickleback fish have swollen, not red bellies. Males react aggressively to red underbellies and also to anything that resembles red underbellies. Males do not react aggressively to swollen underbellies or models that do not have red underbellies. (a) (b)

Egg Rolling in Geese Once a goose detects the sign stimuli,( in this case an egg out of the nest), the goose goes through a series of programmed movements to return egg to nest. The goose will roll baseballs and even beer cans into nest. It will then remove the objects that are not eggs.

Kinesis is a simple movement in response to a stimuli. Fig. 51-4 Kinesis is a simple movement in response to a stimuli. Animals become more or less active in response to stimuli, without any real orientation Moist site under leaf Dry open area Sow bug

A Taxis is movement toward or away from a stimulus. mitosis

Migration is a long regular change in location. Observed in birds, fish, other animals Often pass through environments have never visited. How do they find their way? Can orient themselves using sun. Nocturnal animals can use the North Star. Some evidence that some animals can detect the earths magnetic field.

Fig. 51-5

Behavioral Rhythms Circadian clock is an internal mechansim that maintains a 24 hour activity cycle. Circannual rhythms are linked to the yearly cycle of seasons. Some behavioral cycles are linked to the new and full moon.

The behavioral cycles of the fiddler crab are linked to the tides that cover and uncover its burrow.

Animal Signals and Communication A stimulus transmitted from one animal to another is called a signal. The transmission and reception of signals between animals is communication.

In courtship of fruit flies: a) male recognizes female, (visual communication) then female releases chemicals to attract male (chemical communication). (a) Orienting (b) Tapping (c) “Singing” In b) male taps female’s foreleg (tactile communication, then c) male rubs his wings together, creating a “song”.

Honey Bee Dance Language (a) Worker bees (b) Round dance (food near) (c) Waggle dance (food distant) A 30° C B Beehive 30° Location A Location B Location C

Pheromones are chemical substances that communicate through emitted odors. Serve as reproductive attractants Trigger specific courtship behaviors Can be used to communicate danger

Fig. 51-9 (a) Minnows before alarm (b) Minnows after alarm

Learning is the modification of behavior based on specific experiences Habituation is one of the simplest forms of learning. Habituation is the loss of responsiveness to stimuli that conveys little or no new information. “Cry Wolf Effect” Time and energy can be applied to finding food, or mate and not wasted on irrelevant stimuli.

Imprinting is a behavior that involves both innate and learned components Long lasting behavioral response to a particular individual. Must occur during a sensitive period of development Young imprint on their parent and learn basic behaviors of their species. Some birds will respond to first object they see that has certain characteristics. (a) Konrad Lorenz and geese

Fig. 51-10b (b) Pilot and cranes

Associative Learning After eating a monarch butterfly catepillar (has bad taste), mouse avoids in the future. The ability to associate one environmental feature with another is associative learning. Two types of associative learning: classical conditioning and operant conditioning.

In classical conditioning, an arbitrary stimulus becomes with a particular outcome – “Pavlov’s Dog” Operant Conditioning is the result of trial and error.

Cognition is the most complex form of learning. Processes of knowing Awareness Reasoning Recollection judgement

Agonistic Behavior often involves ritualistic contest that determines which competitor gains access to a resource, such as food or mates.

Altruism Reduction of individual fitness to increase the fitness of other individuals in the population. Belding squirrels give high pitched alarm call to warn unaware individuals, but draw attention of predator to themselves. Honeybee workers are sterile and devote all their energy and labor on behalf of a single fertile female.

Why Altruism? The principle of inclusive fitness may answer the why. Altruism only exists among close relatives – parent sacrifices life to protect young, or siblings, but not distant cousins. Makes sense evolutionarily. These genes are closest to individual and keeps those who share genes in the population. Natural selection that favors altruistic behavior by enhancing the reproductive success of relatives is “kin selection”.

Social learning is the basis of culture and is defined as the transfer of information through copying behavior of other members of the population and the teaching of the behavior.

Fig. 51-32