Animal Behavior
Animal Behavior
 Ethology—study of animal behavior as a branch of
biology. Tends to look at animals in natural
environment.
 Comparative psychology—study of animal behavior
as a branch of psychology. Tends to look at animals in
experimental situations.
 Behavioral ecology—study of the ecological and
evolutionary basis for animal behavior
Animal Behavior
 Mostly studied beginning in early 20th century
 Pioneers
 Ivan Pavlov—association behaviors, conditioned reflex.
Won Nobel Prize in 1904.
 Niko Tinbergen—Individual & social behavior patterns
 Konrad Lorenz—Instinctive behavior, imprinting
 Karl von Frisch—Communication & pheromones in
bees
 Tinbergen, Lorenz, von Frisch won Nobel Prize in 1973
for their behavioral work
Adaptive Success
 Behaviors help promote individual’s
production of offspring
 Give benefit to survival
 Food gathering
 Predator protection
 Mate selection
 Young rearing
 Resource use
 Territory protection
Behavioral Questions
 First described by Niko Tinbergen
 When analyzing behavior, ask the following questions:
 Function—how does the behavior impact on the animal's
chances of survival and reproduction?
 Causation—what are the stimuli that elicit the response, and
how has it been modified by recent learning?
 Development—how does the behavior change with age, and
what early experiences are necessary for the behavior to be
shown?
 Evolutionary history—how does the behavior compare with
similar behavior in related species, and how might it have
arisen through the process of phylogeny?
Instinctive Behaviors
 Nervous system “pre-wired” before
birth/hatching
 Behaviors do not need training
 Garter snakes & slug preference
 Coastal snakes eat slugs
 Inland snakes ignore slugs
 Hybrids intermediate
 Garter snakes & striking
 Captive-born snakes will strike at
model with bird eyes
Instinctive Behaviors
 Fruit flies & mating gene
 Males must perform behavior or
females won’t mate
 Gene can be turned of in males and
turned on in females
 Hormonal influences—voles &
mating
 Females with high oxytocin levels
(due to mating or injections) mate
for life
 Females with oxytocin blocked do
not bond
Instinctive Behaviors
 Fixed action pattern
 Behavior or sequence of behaviors
 Instinctual
 Followed to completion once started
 Not always completely “fixed”, can be
modified
 First described by Tinbergen & Lorenz
 Sign stimulus—outside stimulus that
triggers FAP
 Graylag goose


Will roll a displaced egg back into nest
Will roll ANY egg-like object back into nest
 Many mating displays
 Chick begging


Parent landing at nest
Red spot on beak
Learned Behaviors
 Environment & experiences
influence gene expression
(behavioral)
 Birdsong
 Instinctual behavior
 Variations, dialects exist in
different habitats
 Birds learn pattern in first few
weeks of life
Learned Behaviors
 Macaques—Imo
 Learned to wash potatoes in sea
 Learned to wash wheat by
throwing into sea
 Others performed same behaviors
by observing
 Chimpanzees—tool use
 Varies by region
 Sticks for gathering termites
 Rocks for opening nuts
Learned Behaviors
 Many behaviors related to timing
 Erik Erikson’s 8 stages of
development



As child ages, behaviors develop at
different times
Birth-18 mo, basic trust
6-12 yr, self-confidence or
inadequacy among peers
 Dogs
 Accept new experiences between 412 weeks old
 After 14 weeks old, more fearful of
new things
Learned Behaviors
 Imprinting
 Learning occurs at a particular
stage in life
 Filial imprinting




Lorenz
Many birds will “imprint” on moving
object in 1st 36 hours of life.
Consider that object their parent
Can be useful in rehabilitation
 Sexual imprinting
 Learn characteristics of desirable
mate
 Zebra finches prefer mates that
appear like bird that reared them.
Learned Behaviors
 Association
 Stimulus linked to another
stimulus that may not be
related to the first
 Pavlov



Ring bell before feeding dogs
Dogs salivated
Eventually salivated just with
bell
 Fish moving to surface when
hand seen
 Dog excited when seeing leash
Communication
 Instinctive & learned
 Sent & received among a species
 Signals—single cue, meant to change receiver’s
behavior
 Displays—pattern of behavior, social signal
Communication Signals
 Pheromones
 Signaling—induce receiver to
respond fast


Honeybee alarm calls
Sexual attraction
 Priming—induce physiological
change

Urine of male mice can induce &
enhance estrus of females
Communication Signals
 Acoustical
 Sounds
 Attract females (birds, frogs)
 Alarms (prairie dogs)
 Territory possession (wolves,
birds, kangaroo rats)
 Visual
 Visible changes in behavior
or appearance
 Laid-back vs. erect ears
 Erect hairs
 Color changes
Communication Displays
 More complicated than a signal,
sequence or pattern of behaviors
 Courtship
 Well developed in birds, mammals
 “Dance”
 Often elaborate patterns,
ritualized steps
 Normal movements or structures
exaggerated or frozen
Communication Displays
 Threat
 Signaler prepared to attack
receiver
 Signaler benefits if rival backs
down without fight
 Receiver benefits by avoiding
serious injury or death
 Protection
 Territory
 Mates
Communication Displays
 Information
 Many insects
 Von Frisch & bees


When return to hive, move in
specific patterns
Pattern tells others distance &
direction of food
Sexual Selection
 Competition for reproduction
 Usually female choosing
among males
 Different than courtship
displays, but may include
them
 Nuptial gift—male brings
female food item, female
chooses male with best one
 Many insects, flies, spiders
Sexual Selection
 Lek
 Mating arena
 Males gather in single area &
display or compete
 Female moves among them &
chooses
 Generally compete for center
position
 Deer, some fish, many birds
 Physical competition between
males
 Extravagant physical displays
(peacocks)
Parental Care
 Care of young requires time &
energy
 Could use this for survival & more
reproduction
 Young more likely to survive w/ care
 Cost of care usually outweighed by
survival improvement
 Number of offspring decreases as
length of parental care increases
 The more involved the male is with
care, the more monogamy seen
Parental Care
 No Care
 Neither parent gives any interest after laying eggs
 Most invertebrates, most vertebrates except birds & mammals
 Paternal Care
 Father cares for young
 Rare (seahorses, midwife toads, some birds & mammals)
 Maternal Care
 Mother cares for young
 Most common if any parental care
 Bi-Parental Care
 Both parents care for young
 Most birds, some fish, many mammals
Parental Care
 Infanticide
 Killing of young
 Most often by unrelated males



Eliminates rival males’ genes
May stimulate female to go into
estrus, enabling him to breed
Rats, lions, many other animals
(especially mammals)
 Some females spontaneously
abort when new male takes
over
Social Behavior
 In most habitats, costs
outweigh benefits
 Competition for limited
resources
 Large social groups attract
more predators
 Crowded conditions encourage
spread of parasites & disease
 Animals of the group more
likely to be injured, killed, or
exploited by others
Social Behavior
 Cooperative predator avoidance
 Some species have sentinels that
give alarms

Meerkats, prairie dogs, vervet
monkeys
 Some join in counterattack


Smaller birds mob predatory birds
Ants, bees mob when nest disturbed
 Some have more effective defense


Sawfly caterpillars
“Selfish Herd”—protect collective selfinterest, protect young
Social Behavior
 Cooperative hunting
 Larger prey than could be killed
individually
 Prey that could otherwise fight or
outrun predator
 Two or more individuals
 Many animals of all kinds

Wolves, lions, wild dogs, starlings,
orcas, tuna, army ants
 Reproductive advantage
 Easier access to mates
 Communal care of young
 Ants, bees, rats, primates
 Cost of care distributed among
adults
Social Behavior
 Dominance Hierarchies
 Uneven distribution of resources
 Dominant gain more resources
 Subordinates might not survive on
own
 Subordinates might live long
enough to reproduce
Social Behavior
 Eusocial animals
 “True social”—highest level of
hierarchy division
 Distinct social classes/castes
 Division of labor
 Breeding female dominates,
others don’t breed
 Remain together for many
generations
 Insects (wasps, bees, ants,
termites)
 Mole rats
Social Behavior
 Eusocial animals (cont.)
 Altruistic behavior—helps
others, harms or gives no
benefit to performer


Australian honeypot ant
worker—living container
Soldier termite—bombards,
nozzle head
 Genes not passed, but can
be favored if closest relative
will benefit
 2 siblings as genetically
identical as parent &
offspring