fixed action patterns

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Transcript fixed action patterns

Animal Behavior
• Animal Behavior is defined as observable
actions that an animal does when
interacting with its environment.
• Ethology – the study of animal behavior
• Three scientists are well known for their
studies in animal behavior:
• Karl von Frisch - studied honey bee
behavior in the early 1900’s.
– He discovered that honey bees can see in
color, they can identify plants by smell and
that they communicate using a “waggle dance”
Waggle Dance
• Konrad Lorenz – showed that the same
stimulus may elicit very different forms of
behavior in different animal species.
– He described imprinting behavior using geese
• Niko Timbergen – researched innate
behavior (instinct) and simple forms of
learning.
Behavior can be interpreted in terms of:
Proximate causes - immediate interaction
with the environment
Ultimate causes - evolutionary differences
and evolutionary consequences
• A classic Tinbergen experiment deals with
the nesting behavior of the digger wasp
• The female wasp often excavates and cares
for four or five separate nests
• Tinbergen used this experiment to test his
prediction that digger wasps use landmarks
to keep track of the location of their nests
In the experiment, Tinbergen placed a circle
of pinecones around a nest opening
Nest
1
After the female flew away, Tinbergen moved
the pinecones a few feet to one side of the nest
opening.
When the female wasp returned, she flew to
the middle of the circle of pinecones rather
than to the actual nest opening.
Nest
2
No Nest
Tinbergen next arranged the pinecones in a
triangle around the nest and made a circle of
small stones off to one side of the nest
opening
This time the wasp flew to the stones
Nest
3
No Nest
• The wasp cued in on the arrangement of the
landmarks rather than the landmarks
themselves.
• This experiment demonstrated that the wasp
did use landmarks and that she could learn
new ones to keep track of her nest.
Behavioral ecologists are especially
interested in the ultimate causes of
behavior, which are evolutionary 
Natural selection preserves behaviors
that enhance fitness
Nature or Nurture
• Animal behavior often involves a
combination of genetic programming
(innate behavior) and environmental
experiences (learning)
both genes and the environment influence the
development of behavioral phenotypes- just
like any other traits
The gathering
of nest
materials by
lovebirds has
genetic and
environmental
components
Single long strip carried in beak
(Fischer’s lovebird)
Several short strips tucked under feathers
(peach-faced lovebird)
Tucking
failure
Strip in
beak
Hybrid behavior
Innate behavior often appears
as Fixed Action Patterns
• Sign stimuli (often a simple cue in an
animal’s environment) trigger innate,
essentially unchangeable fixed action
patterns (FAPs)
• The genetic programming underlying
FAPs ensures that such activities are
performed correctly without practice.
• The graylag goose
always retrieves an egg
that has been bumped
out of her nest in the
same manner
– This is a fixed action
pattern
– She carries this sequence
to completion, even if
the egg slips away during
the process
• An example of a FAP may be someone that
has memorized a poem or piece of music
but must start over at the beginning if
interrupted.
• Once an animal initiates a FAP it usually
carries out the sequence to completion,
even if it receives different stimuli before it
finishes.
Several key events in the life cycle of the
European cuckoo are determined by fixed
action patterns
Egg-laying behavior
1
2
3
The behavior of the
cuckoo hatchling
ejecting the host eggs
from the nest.
Which is the sign stimulus and which is
the fixed action pattern?
The feeding behavior
of a foster mother to
the cuckoo chick
Which is the sign stimulus and which is
the fixed action pattern?
Fixed Action Patterns make nest
parasitism possible
Brown-headed cowbird
is a local nest parasite
What evolutionary changes
must happen to prevent nest
parasitism?
According to biologists at the University of California, Santa Cruz, coots have
evolved a remarkable set of cognitive abilities to thwart other coots that lay
eggs in their neighbors' nests. In 2003, the researchers showed that coots can
count their own eggs and reject ones laid in their nests by other coots. Their
latest findings, published this week in Nature, show that coot parents can tell
the difference between their own chicks and any impostors that manage to
hatch in their nest, and they will violently reject most impostor chicks.
Learning
• Learning ranges from simple behavioral
changes to complex problem solving
• Learning is a change in behavior resulting
from experience
Habituation
• Habituation is one of the simplest forms of
learning
– An animal learns not to respond to a repeated
stimulus that conveys little or no information
– For example, birds eventually become
habituated to scarecrows. We become
habituated to background noises.
Imprinting
• Imprinting is irreversible learning limited to
a sensitive period in an animal's life. It
enhances fitness by enabling rapid learning
• Example: Lorenz used the graylag goose to
demonstrate imprinting. He took over the
maternal role for a group of goslings
• Not all examples of imprinting involve
parent-offspring bonding
Although newly hatched salmon do not receive
any parental care, they imprint on the complex
mixture of odors unique to the freshwater
stream where they hatch
This allows salmon to find their way back to the
stream to spawn after spending a year or more
at sea
• Imprinting plays an important role in song
development for many kinds of birds
Association
• In association an animal learns that a
particular stimulus or response is linked to
a reward or punishment.
• “Skinner box” is that classic stimulus –
response study in which a rat finds and
manipulates a lever and is rewarded by
food. The rat quickly learns to associate
depressing the lever with a food reward.
• These ducks have learned to associate humans
with food handouts
• They congregate rapidly whenever a person
approaches the shoreline
• In a natural setting associative learning is
called trial – and – error learning.
• I.E. Predators quickly learn to associate
certain prey with painful experiences like
the porcupine.
Imitation
• Imitation is learning by observing and
mimicking the behavior of others.
• Imitation is not limited to a sensitive
period.
• I.E. Predators seem to learn some of their
basic hunting tactics by observing and
imitating their mother
Problem Solving
Solving a problem involves
using prior experience,
observation, and insight to
find the solution.
An animal's behavior reflects its
evolution
• Behavior is an evolutionary adaptation that
enhances survival and reproductive success
• Behavior evolves as natural selection finetunes an animal to its environment
– Nest location by digger wasps
– Imprinting of goslings
Biological rhythms synchronize
behavior with the environment
• Animals exhibit a great variety of rhythmic
behavior patterns
• Circadian rhythms are patterns that are
repeated daily
– Sleep/wake cycles in animals and plants
• Circadian rhythms appear to be timed by an
internal biological clock
In the absence of environmental cues, these
rhythms continue
– But they become out of phase with the
environment
12:12 (natural)
Constant
darkness
Animal movement may be oriented
to stimuli or landmarks
• Movement in a directed way enables
animals to
– avoid predators
– migrate to a more favorable environment
– obtain food
– find mates and nest sites
TYPES of ANIMAL MOVEMENT
1. kinesis- simplest type of animal movement random movement in response to a stimulus
2. taxis- another simple type
–
–
A more or less automatic movement directed
toward or away from some stimulus
Examples include rheotaxis (current) chemotaxis,
and phototaxis
3. Some animals use landmarks to find their way
within an area
Movement from place to place often
depends on internal maps
• Many animals formulate cognitive maps or mental
maps. These are internal representations of spatial
relationships among objects in their surroundings
(wasp example)
– You giving someone directions to your house by
picturing the route in your brain.
• Some animals undertake long-range migrations
– whales, sea turtles, birds, monarch butterflies
How Do Animals Navigate??
1.
2.
3.
4.
5.
Landmarks – gray whale
Stars – many birds
Sun – monarch butterfly
North Star – indigo bunting
Earth’s magnetic field
What about when it’s cloudy?
Many animals have magnetite in their
brains – a mineral which contains iron
and allowing them to orient to the earth’s
magnetic field
Migrating gray whales use coastal landmarks to
stay on course
FEEDING
GROUNDS
Arctic Ocean
Siberia
Alaska
Pacific
Ocean
Baja California
NORTH
AMERICA
Atlantic
Ocean
BREEDING GROUNDS
Gray whales have the longest migration for any mammal
traveling 2000 Km yearly (1243 miles).
The indigo
bunting
learns a star
map and
navigates by
fixing on the
North Star
Paper
Ink pad
Funnelshaped
cage