50
Animal Behavior
Lecture Outline
I.
Understanding behavior
A. Behavioral ecology is the study of behavior in natural environments from an
evolutionary perspective
B. Behavioral ecologists use cost-benefit analysis to understand specific
behaviors
1. A behavior may contribute to direct fitness, an individual's reproductive
success
2. A behavior may also have costs
3. If the benefits are greater than the costs, then that behavior is adaptive
II.
Behavior depends on the interaction of genes and environmental factors
A. All behaviors or the capacity for behavior is inherited in some way
1. Instinct is innate, or inborn, behavior
B. Behavior depends on physiological readiness
1. Behavior primarily depends on the nervous and endocrine systems
2. Behaviors are influenced by readiness of the animal and environmental
signals
C. Many behavior patterns depend on motor programs
1. Motor programs are coordinated sequences of muscular actions
2. Fixed action patterns (FAPs) are genetically influenced behaviors
3. Sign stimuli or releasers result in FAPs
III.
Animals learn from experience
D. Behavior is modified by learning
1. Learned behaviors are those influenced by experience
E. An animal habituates to irrelevant stimuli
F. Imprinting occurs during an early critical period
1. Imprinting occurs soon after birth
2. Konrad Lorenz showed that newly hatched birds imprint on the first
moving object seen after hatching
G. In classical conditioning, a reflex becomes associated with a new stimulus
1. Pavlov conducted experiments on dogs
a) The bell associated with the presentation of food resulted in salivation
of the dog in response to ringing of a bell
H. In operant conditioning spontaneous behavior is reinforced
1. Positive reinforcement rewards behavior with a positive response
2.
Negative reinforcement causes an animal to perform a behavior to avoid a
negative stimulus
I. Insight learning uses recalled events to solve new problems
1. Insight learning, the most complex form of learning, is seen in primates
and some birds and other mammals
J. Play may be practice behavior
1. Play may be a learning of coordination, social skills, and adult behaviors
IV.
Biological rhythms and migration
K. Biological rhythms affect behavior
1. Some behaviors are oriented around environmental cues such as tides,
solar cycles, and annual patterns
2. Circadian rhythms are daily activities
a) These rhythms are controlled by biological clocks
b) Diurnal animal are active during the daytime
c) Nocturnal animals are active during the night
d) Crepuscular animals are active during dusk and dawn
3. Lunar cycles follow the phases of the moon
4. Biological rhythms are controlled by an internal clock
a) In vertebrates, the master clock is located in the suprachiasmatic
nucleus (SCN) in the hypothalamus
b) The SCN sends rhythmic signals to the pineal gland, which in turn
secretes melatonin, a hormone that promotes sleep in humans
L. Migration involves interaction among biological rhythm, physiology, and
environment
M. Proximate causes of migration include signals from the environment
1. Migration is a long distance movement to a different area, then a return to
the original area
2. Migration may be triggered by day length
3. Direction of migration may be according to celestial, magnetic, or olfactory
cues
4. Navigation includes both compass sense and map sense
a) Compass sense is a directional sense
b) Map sense is an awareness of location, involving information about
distance and time
V.
Efficient foraging behavior contributes to survival
N. Optimal foraging is a set of hypotheses describing foraging by animals, which
optimizes time and reward
O. Animals may adopt varying foraging strategies to optimize reward
VI.
Social behavior has both benefits and costs
P. Social behavior is typically the interaction between members of the same
species
1.
Schooling behavior, social foraging, and societal behavior are all social
behaviors
2. Aggregations are simply groups of animals of the same species brought
together for something like foraging, but does not imply social interactions
Q. Communication is necessary for social behavior
1. Communication results in the modification of behavior by another
organism
2. Animals communicate in a wide variety of ways
a) Communication involves sounds, scent, or even electrical signals
3. Some animals communicate by scent
a) Pheromones are chemical signals used in communication
b) Pheromones may result in immediate or long-term effects
c) Pheromones are often involved in sexual responses
R. Dominance hierarchies are social rankings
1. Dominance hierarchies suppress aggression
a) Dominance hierarchies result in little wasted fighting
2. Many factors affect dominance
a) Aggression is influenced by sex hormones
S. Many animals defend a territory
1. The home range is the area an animal inhabits
2. The territory is a section of the home range that is defended
a) Territoriality is well studied among birds
b) Territoriality decreases aggressive conflicts
c) Territoriality is closely tied to reproductive behavior
T. Some species that engage in social behavior form societies
1. A society is an actively cooperating group of individuals belonging to the
same species
2. Social insects form elaborate societies
a) Bee societies consist of a single queen, many worker females, and a
few drones
b) Drones develop from unfertilized eggs and are haploid
c) Workers develop from fertilized eggs and are diploid
d) Workers are more related to each other than they would be to their
own offspring (if they had them, which they do not)
(1) This results in workers deferring reproduction to care for the
offspring of the queen
e) The communication between workers is a dance that conveys
information about location of a food source
3. Vertebrate societies tend to be relatively flexible
a) The behavioral plasticity of vertebrates makes possible the
transmission of culture in some bird and mammal species
b) About 17 behaviors that can be considered cultural have been
described in whales, dolphins, and porpoises
c) 39 chimpanzee behaviors are considered cultural
U. Sociobiology explains human social behavior in terms of adaptation
1. Sociobiology focuses on the evolution of social behavior through natural
selection
2. E.O. Wilson synthesized many of the modern theories of sociobiology
3. Sociobiology is controversial, in part because of ethical implications
VII.
Sexual selection
V. Sexual selection is a type of natural selection describing variability in
reproductive success in different members of a population
W. Dominance and ornamental traits influence mate choice
1. Leks are display areas for males attempting to attract females
a) Leks are seen in some insects, birds, and bats
2. Courtship rituals are often energy-intensive
X. Sexual selection favors polygynous mating systems
1. Pair bonds exist between animals of the opposite sex to ensure mating and
rearing of offspring
2. Polygynous animals have male impregnation of more than one female,
with little parental care of the young by the male
3. Polyandrous females mate with more than one male
4. In monogamy, organisms may have only one mate, for a breeding season
(very common in birds) or for a lifetime (much less common)
Y. Some animals care for their young
1. It is typically advantageous only to care for one’s own offspring or the
offspring of related individuals
VIII. Helping behavior
Z. Altruistic behavior is that which appears to be selfless
1. Inclusive fitness includes the genes of the individual that are passed to the
next generation, even if they aren’t passed on by that particular individual
(i.e. they are passed on to the offspring of a related individual)
2. Inclusive fitness may be measured by the coefficient of relatedness
3. Kin selection increases inclusive fitness
AA. Cooperative behavior may have alternative explanations
1. Sentinel behavior has been a prime example of kin selection
2. However, guarding could result from selfish behavior because the sentinels
could more easily escape and derive other benefits
Research and Discussion Topics

Describe the eusocial behavior seen in a rodent, for example the naked mole rat.
How do their societies compare to the eusocial behavior in the hymenopterans (such
as bees)?