Download Chapter 29

Chapter 29
Animal Behavior
Section 1
Elements of Behavior
Behavior and Evolution
• BEHAVIOR is the way an organism reacts to stimuli in its
environment.
• Behaviors essential to SURVIVAL and reproduction include
finding and catching FOOD, selecting a HABITAT, avoiding
PREDATORS, and finding a MATE.
Behavior and Evolution
• Some behaviors can be influenced by GENES and can be
INHERITED.
• Certain behaviors evolve under the influence of NATURAL
SELECTION:
Behavior and Evolution
• If a behavior increases an individual’s FITNESS and is influenced
by GENES, it tends to spread through a population.
• Over many generations, ADAPTIVE behaviors can prove
important in the survival of populations and species.
Innate Behavior
• An INNATE BEHAVIOR, also called an instinct, is fully
functional the first time it is performed, although the animal has
no previous experience with the STIMULUS.
• All innate behaviors depend on patterns of NERVOUS SYSTEM
activity that develop through complex interactions between
GENES and the ENVIRONMENT.
Learned Behavior
• Acquiring changes in behavior during one’s lifetime is called
LEARNING. There are four types:
• HABITUATION is the process by which an animal decreases
or stops its response to a REPETITIVE STIMULUS that
neither rewards nor harms the animal.
Learned Behavior
• In CLASSICAL CONDITIONING, a certain stimulus comes to
produce a particular RESPONSE, usually through an association
with a POSITIVE or NEGATIVE experience.
• OPERANT CONDITIONING (a form of trial-and-error
learning) is the use of a REWARD or PUNISHMENT to teach
an animal to behave a certain way through REPEATED practice.
Learned Behavior
• INSIGHT LEARNING occurs when an animal applies to a new
situation something that it learned previously in another context.
Complex Behaviors
• Many complex behaviors combine INNATE behavior with
LEARNING. Imprinting is a complex behavior.
• IMPRINTING is the process by which some animals, such as
BIRDS, recognized and follow the first moving object they see
during a critical period in their early lives.
Section 2
Animals in Their Environments
Behavioral Cycles
• Many animals demonstrate daily or seasonal cycles in their
behavior.
• CIRCADIAN RHYTHMS are behavioral cycles that occur
daily.
• MIGRATION is the seasonal movement from one
environment to another.
Behavioral Cycles
• MIGRATION is the seasonal movement from one
environment to another.
• For example, many birds find food and nesting sites in the
north in the SUMMER, but they fly south to warmer climates
for the WINTER.
Social Behavior
• Interactions among animals of the same species are social
behaviors. There are several types:
• Animals (usually the MALES) perform COURTSHIP
behaviors to attract a mate.
• An elaborate series of courtship behaviors is a COURTSHIP
RITUAL.
Social Behavior
• Many animals occupy a specific area, or TERRITORY, that they
defend against COMPETITORS.
• Animals may use threatening behaviors, or AGGRESSION, to
defend their territories.
• Animals may also use aggression when they compete for
RESOURCES.
Social Behavior
• Some animals form a SOCIETY, or a group that interacts closely
and often COOPERATIVELY.
• The theory that helping a relative survive increases the chance of
transmitting one’s own genes is KIN SELECTION.
Social Behavior
• The most complex animal societies are those formed by social
INSECTS such as ANTS, BEES, and WASPS.
• All animals in the society cooperate closely to perform complex
tasks, such as NEST CONSTRUCTION.
Communication
• The passing of information from one individual to another is
COMMUNICATION.
• Animals use a variety of signals for communication, including
VISUAL, CHEMICAL, and SOUND.
• LANGUAGE is a system of communication that combines
SOUNDS, SYMBOLS, and GESTURES according to rules
about sequence and meaning.