Transcript ch. 51 - animal behavior

Ch. 51 – Animal Behavior
Overview
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Behavioral ecology is a study
of how behavior is controlled
and how it develops, evolves,
and contributes to survival
and reproductive success
When you study animal
behavior, there is a wide
continuum of them – from
innate (born with) to complex
learned behavior
Scientific questions about
behavior can be divided into
two classes:
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Those that focus on the
immediate stimulus and
mechanism for the behavior
(proximate)
– Those that explore how the
behavior contributes to survival
and reproduction (ultimate)
What is Behavior?
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Behavior is what an
animal does and how
it does it
Behavior includes
muscular and
nonmuscular activity
Learning is also
considered a
behavioral process
Innate Behavior - Instinct
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Instinct is basically
anything you have
from day one
 ex – a babies “moro”
response; grasping
reflex that have
evolutionary
overtones – babies
that can’t hold on end
up falling)
Innate Behavior cont - Fixed
Action Patterns
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A fixed action pattern (FAP) is a
sequence of unlearned, innate
behaviors that is unchangeable
Once initiated, it is usually
carried to completion
A FAP is triggered by an
external sensory stimulus
known as a sign stimulus
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Ex - In male stickleback fish, the
stimulus for attack behavior is the red
underside
ex – if you take an egg from a ducks
nest and set it beside the nest, the
duck will pull it back in – but they will
do the same thing for any similar
object like a billiard ball or light bulb)
This occurs in humans when you do
an “eyebrow flash”
Innate Behavior cont - Imprinting
Imprinting is a behavior
that includes learning and
innate components and is
generally irreversible
 It is distinguished from
other learning by occurring
during a “critical period”
 A sensitive or critical period
is a limited developmental
phase that is the only time
when certain behaviors can
be learned
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Ex - Conservation biologists have taken
advantage of imprinting in programs to
save the whooping crane from extinction
BEHAVIOR: Young geese follow and imprint on their mother.
PROXIMATE CAUSE: During an early, critical developmental
stage, the young geese observe their mother moving away
from them and calling.
ULTIMATE CAUSE: On average, geese that follow and
imprint on their mother receive more care and learn
necessary skills, and thus have a greater chance of
surviving than those that do not follow their mother.
Innate Behavior cont - Directed
Movements
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Many animal movements are
under genetic influence –
these are called directed
movements
Innate behavior is
developmentally fixed and
under strong genetic influence
Many features of migratory
behavior in birds have been
found to be genetically
programmed
Behavior cont - Kinesis
A kinesis is a simple
change in activity in
response to a stimulus, like
temperature
 For example, sow bugs
become more active in dry
areas and less active in
humid areas (estivation is a
decrease in metabolism in
hot weather)
 Bears and other animals
slow their metabolism
when it’s cold and food is
scarce (hibernation)
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Behavior cont - Taxis
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A taxis is a more or less
automatic, oriented movement
toward or away from a
stimulus (similar to tropism,
except the organism has
motility)
Many stream fish exhibit
positive rheotaxis; they
automatically swim in an
upstream direction
This taxis prevents them from
being swept away and keeps
them facing the direction from
which food will come
Behavior cont (learned)–
associative learning
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You start to
associate one
stimuli with a certain
effect (Pavlov’s dog)
Bears will associate
food with dumpsters
Behavior cont – Operant
conditioning
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BF Skinner and operant
conditioning (when you
learn something through
trial and error)
Created the Skinner Box,
where he put a rat in a box
and through trial and error
taught them to push levers
to get food
Can teach very complex
behavior through this
process
Josh Klein – crow vending
machine (there was also a
crow around Ogden that
would steal parking tickets
off cars)
Behavior cont - habituation
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When you get the same
stimuli over and over
again and eventually
learn to ignore it
When prairie dogs
sense a threat, they
raise their heads back
and let out a scream,
but if humans go around
them often enough, they
get habituated to their
presence and stop this
behavior
Behavior cont – observational
learning
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Watching another
organism and mimicking
that
The octopus is a master
mimic
If you put them in an
aquarium with a bottle,
about half of the octopi
will be able to do open
it; if you put an octopus
in an adjacent tank, they
will watch the ones that
will open the bottle then
do it themselves
Behavior cont - insight
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If you give an animal a
problem, will they be
able to think it through
and solve it?
Dolphins, chimps, crows
Usually happens in
animals that live socially
Ex – you’re given
matches, a small box
with tacks in it and a
candle, and you want to
stick a candle to the
wall. How do you do
this?
Environment influencing behavior
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Research has revealed
that environmental
conditions modify many
of the same behaviors
Diet can influence choice
of mate
 Some studies suggest dogs can
become more aggressive on a
high protein diet
 Studies suggest children who are
malnourished lag behind well-fed
children in school academically
(brain doesn’t develop the same)
Communication - Signals and Responses
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Communication is the
reception of and response to
signals
In behavioral ecology, a signal
is a behavior that causes a
change in another animal’s
behavior
Animals communicate using
visual, auditory, chemical,
tactile, and electrical signals
The type of signal is closely
related to lifestyle and
environment
Communication Examples
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Chemical - Many animals
that communicate through
odors emit chemical
substances called
pheromones
 When a minnow or catfish is
injured, an alarm substance in
the fish’s skin disperses in the
water, inducing a fright response
among fish in the area
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Auditory - Experiments with
insects have shown that
courtship songs are under
genetic control
Natural selection favors behaviors that
increase survival and reproductive success
Genetic components of behavior
evolve through natural selection
 Reto Zach conducted a costbenefit analysis of feeding
behavior in crows
 The crows eat mollusks called
whelks but must drop them from
the air to crack the shells
 Optimal flight height correlated
with fewer drops, indicating a
trade-off between energy gained
(food) and energy expended
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Mating systems and mate choice
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Behavior can affect fitness by
influencing foraging and mate
choice
The mating relationship between
males and females varies greatly
from species to species
In many species, mating is
promiscuous, with no strong pairbonds or lasting relationships
In polygyny, one male mates with
many females
The males are often more showy
and larger than the females
In polyandrous systems, one
female mates with many males
The females are often more showy
than the males
Mating systems and mate choice
cont.
Needs of the young are an
important factor constraining
evolution of mating systems
 Certainty of paternity influences
parental care and mating
behavior
 Certainty of paternity is much
higher when egg laying and
mating occur together, as in
external fertilization
 In species with external
fertilization, parental care is at
least as likely to be by males
as by females
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The concept of inclusive fitness can account for most
altruistic social behavior (most behavior is selfish)
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Natural selection favors behavior that
maximizes an individual’s survival and
reproduction
On occasion, some animals behave in
ways that reduce their individual
fitness but increase the fitness of
others – called altruism
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In naked mole rat populations,
nonreproductive individuals may sacrifice their
lives protecting the reproductive individuals
from predators
Altruism can be explained by inclusive fitness
Inclusive fitness is the total effect an
individual has on proliferating its
genes by producing offspring and
helping close relatives produce
offspring