Animal Behavior
Introduction - Animal Behavior
 Why do animals do what
they do?
 Why do birds sing?
 How do sea turtles navigate
the ocean to lay their eggs
on the same beach where
they were hatched?
 How do honeybees know
when the hive needs more
food?
Image from http://www.nps.gov
Image from http://www.scottcamazine.com
Introduction
 Animal behavior asks
what, why, and how.
 Animal behavior is
also referred to as
ethology.
 Scientists who study
animal behavior are
called ethologists.
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Introduction
 Animal behavior
is centered
around the ability
to move.
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Animals seek
food, water,
shelter.
Animals play
with each other.
Animals seek
mates.
Introduction
Behavior results as a
reaction to a stimulus.
A stimulus is a detectable
change in the animal’s internal
or external environment.
Hunger.
Sound.
Pain.
Visual cues.
Hormonal changes.
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Introduction
Ethologists do not attempt to describe
WHY an animal does a behavior before
describing WHAT the animal is doing.
This removes as much bias as possible – good
scientists don’t want to just “see what they want
to see”.
Need to make objective observations of animal
behaviors, analyze the data statistically, then
come to conclusions about WHY an animal
behaves a certain way.
Introduction
For example, you see two gophers
interacting with each other, rolling and
hopping around, running to and from each
other.
 As a behavioral ecologist, you would first state
the behavior you are observing.
 Once you made the observations about WHAT
was happening, you could begin to determine
WHY they are behaving that way.
Introduction
 The behavior you
observed could
have been many
different things.
 Play.
 Mating rituals.
 Aggression,
defending territory.
How to determine WHY – action patterns.
Action patterns are complex behaviors that
are always repeated the same way by a
species of animal.
 We say that action patterns are stereotyped,
since they occur the same way each time, and
through to completion.
 After repeatedly observing action patterns, an
ethologist can analyze the data statistically.
 Only then do we attempt to determine WHY a
behavior is being done.
Fixed Action Patterns (FAP) are INNATE
Niko Tinbergen
 Niko Tibergen was a
pioneer in the field of
animal behavior.
He observed animals in
their natural conditions,
then manipulated, or
varied the conditions to
see how the animals
responded.
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Niko Tinbergen
 Tinbergen observed how a
wasp called the beewolf
finds its nest among other
beewolf nests.
 He observed that the beewolf
would circle its nest in an everwidening circle before flying away
to hunt.
 This behavior was an action
pattern – it was performed
exactly the same way each time.
Image from http://www.sciencenews.org
Niko Tinbergen
 After the beewolf flew off,
Tinbergen would move certain
landmarks around the nests.
 When the beewolf returned, it
was disoriented.
So, by manipulating the
beewolf’s environment,
Tinbergen came to the
conclusion that the beewolf
commits landmarks to memory
to be able to find its nest when it
comes back from hunting!
Image from http://www.earthlife.org
Niko Tinbergen

Tinbergen had to describe and
investigate WHAT the
organism was doing before
attempting to explain WHY.
More on Action Patterns
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 The egg-rolling
behavior of the
greylag goose is a
good example of an
action pattern.
 Niko Tibergen and
another pioneer in
ethology, Konrad
Lorentz, originally
observed this
behavior.
More on Action Patterns
 The goose will roll an egg
that is outside the nest back
into the nest in the same
manner every time.
Interestingly, the goose will
do this with any round object
placed outside the nest!
Every time this action pattern
is initiated, it is carried
through to completion.
Proximate vs. Ultimate Causes
 The question of “WHY” can have different
answers.
 Proximate causes are related to internal
changes in the animal.
Hormones.
Messages from the nervous system.
 “Proximate” means close.
 Ultimate causes are related to the survival and
reproductive success of the animal.
 “Ultimate” means furthest, or utmost.
Proximate vs. Ultimate Causes
 An example incorporating both
proximate and ultimate causes:
Belding’s ground squirrels.
When males reach about two
months old, they leave the
burrow where they were born.
 It is an increase in testosterone, or a
hormonal change that triggers this
behavior.
 So, the proximate cause of the nestleaving behavior involves the
increase in testosterone levels in the
squirrel.
Proximate vs. Ultimate Causes
There is more to the story than just
hormones!
 When males leave the nest, they avoid
inbreeding with sisters or cousins, etc.
 Their offspring are therefore healthier.
 The male offspring inherit the same genetic
information that induces them to leave their nests
at a young age.
 So, this behavior is passed on genetically, and it
makes for a healthier population of squirrels.
 Avoiding inbreeding is therefore the ultimate
cause of this “early nest-leaving” behavior.