Download Chapter 6: Behaviour

Chapter 16: Behaviour
Lesson Objectives:
(a) explain the advantages to organisms of innate behaviour;
(b) describe escape reflexes, taxes and kineses as examples
of genetically-determined innate behaviours;
The study of behaviour – ethology!
Tinbergen’s experiment:
http://www.sumanasinc.com/webcontent/animations/content/behaviors.html
Behaviour is action that alters
the relationship between an
organism and its environment
Nikolaas (Niko) Tinbergen
Dutch zoologist
1907-1988
Received Nobel Prize in Physiology or
Medicine in 1973 with von Frisch and
Lorenz for discoveries concerning
organisation and elicitation of individual
and social behaviour patterns in animals!
The study of behaviour – ethology and psychology!
Ethologists such as Tinbergen study the natural behaviour
of animals in their natural environments
They are interested in the evolutionary basis of behaviour
and tend to focus on simple, inherited behaviour patterns
Psychologists carry out experiments in the lab. They are
interested in how animals learn new patterns of behaviour
This often focuses on the differences between behaviour
patterns of different animal species (comparative
psychology)
Behaviouralism = study of how rewards and punishments
could affect responses to different stimuli
What causes behaviour?
Behavior may occur as a result of …
• an external stimulus (e.g., sight of a predator)
• internal stimulus (e.g., hunger)
• or, more often, a mixture of the two (e.g., mating
behavior)
Bird of Paradise
mating ritual
The great debate …
Nature vs Nurture?
Behaviour is largely
controlled by genes
Instinctive
Innate (in-built)
Learned
Depends upon
experiences
Alex – the African Grey Parrot
Owned by Irene Pepperberg (researcher) for 30 years
Vocabulary of over 100 words
Could ‘identify 50 objects, 7 colours, 5 shapes,
quantities up to and including 6 and a zero-like
concept’
Pepperberg said that the talking parrot had, "the
emotional equivalent of a 2 year-old child and
intellectual equivalent of a 5 year-old."
http://www.youtube.com/watch?v=VZ2j1jOwAYU
Innate (instinctive) behaviour
‘a pattern of inherited, pre-set behaviour that does not
require learning or practice’
We assume the animal does not ‘know’ what to do (ie:
doesn’t think about it and make decisions) – the pattern of
behaviour is due to the ‘hard-wiring’ of its nervous system
which is inherited
Inherited behaviour evolved in the same way as any other
characteristic (eg: colour) evolved
These behaviours are ‘stereotyped’ (all performed in the
same way each time)
A salamander raised away from
water until long after its siblings
begin swimming successfully will swim
every bit as well as they the very
first time it is placed in the water
Instinct …
Instincts are complex behavior patterns which, like
reflexes, are inborn
They are:
rather inflexible
valuable at adapting
the animal to its
environment
So instincts are inherited just
as the structure of tissues and
organs is
• The African peach-faced lovebird carries
nesting materials to the nesting site by
tucking them in its feathers.
• Its close relative, the Fischer's lovebird, uses
its beak to transport nesting materials.
• The two species can hybridize.
• When they do so, the offspring succeed only
in carrying nesting material in their beaks.
Nevertheless, they invariably go through the
motions of trying to tuck the materials in
their feathers first
Reflex actions
Rapid, automatic responses to stimuli
In humans – does not involve
conscious thought (in animals it is
impossible to tell if they have
conscious thought!)
Can be rapid and brief behaviour
patterns (blinking = startle reflex)
or longer term (standing still)
APs pass along a reflex arc:
1. Receptor picks up information
from stimulus
2. APs travel to brain or spinal cord –
to intermediate neurone
3. APs travel via motor neurone to an
effector
Modifying stereotyped (innate) behaviour by experience
Stereotyped = always carried out in a characteristic way
with similar sequences and patterns of movement
Stereotyped behaviour is largely innate (but not
necessarily so)
Eg: Larus articilla (laughing gulls) chick feeding
Basis of begging for food by
grasping parent’s beak is
INNATE (when they are newlyhatched they are not so good at
it!)
REFINEMENT – by learning
they get better, they rotate
their heads after opening their
beaks allowing them to grab the
parent’s beak
Examples of innate behaviour within organisms
Escape reflex
Escape reflex depending on stimuli
Kineses
Woodlice and choice chambers mini
practical!!!
Taxes
Nematode responding to light
Phototaxis in Daphnia woo hoo
Learning
Lesson Objectives:
To outline the methods and conclusions of classic
experiments to investigate the nature of learned
behaviour
Simple learned responses
Habituation = a reduction in a previously-displayed response
when no reward or punishment follows
Eg: make an unusual sound and a
dog will turn towards it
If the stimulus is given repeatedly
and nothing either pleasant or
unpleasant happens to the dog, it
will soon cease to respond.
This is not due to fatigue or sensory adaptation – it is
learned!
It is long lasting (up to months between stimuli)
Simple learned responses
Sensitisation = an increase in the response to an innocuous
stimulus when that stimulus occurs after a punishing
stimulus
Eg: When the siphon of the sea
slug Aplysia is gently touched, the
animal withdraws its gill for a
brief period.
However, if preceded by an
electrical shock to its tail, the
same gentle touch to the siphon
will elicit a longer period of
withdrawal
The sensitization response to a single
shock (blue bar) dies out after about an
hour, and returns to baseline after a day
(yellow)
SHORT TERM MEMORY!
Learned behaviours
EVERY ANIMAL THAT HAS EVER BEEN STUDIED
HAS SHOWN AT LEAST SOME ABILITY TO LEARN
Learning = a change in behaviour as the result of
experience
= a process which manifests itself by adaptive
changes in individual behaviour as a result of
experience
Memory is an important
part of learning!
Learned behaviours
Nereis pelagica (marine clamworm) – lives in burrows,
stretching out tentacles to trap food
If a shadow passes over – quickly withdraws into burrow
Repeated shadows – stops responding to it (habituation)
Learned behaviours – Pavlov’s Dogs
Ivan Pavlov (1849-1936)
Russian Psychologist
First person to describe
classical conditioning
•The conditioned response is
probably the simplest form of
learned behavior. It is a
response that — as a result of
experience — comes to be
caused by a stimulus different
from the one that originally
triggered it
Conditioning bees
Honeybees can be conditioned to seek food on a piece of
blue cardboard
By offering other colors to a blue-conditioned bee, Karl
von Frisch found that honeybees can discriminate between
yellow-green, blue-green, blue-violet, and UV
•After a period of feeding from a dish
placed on blue cardboard, the bees
return to an empty dish on a clean blue
card. They are able to distinguish the
blue card from others of varying shades
of gray
Other types of conditioning
Pavlov's dogs were restrained and the response being
conditioned (salivation) was innate. But the principles of
conditioning can also be used to train animals to perform
tasks that are not innate
In these cases, the animal is placed in a setting where it
can move about and engage in different activities.
Other types of conditioning
• The experimenter chooses to reward only one
behaviour, e.g., turning to the left.
• By first rewarding (e.g., with a pellet of food) even
the slightest movement to the left and then only
more complete turns, a skilled experimenter can — in
about 2 minutes — train a naive pigeon to make a
complete turn.
• A little more work and the pigeon will pace out a
figure eight.
Such training is known as
instrumental conditioning or
operant conditioning
• The latter term was
coined by B. F.
Skinner, whose skill
with the technique
enabled him to train
pigeons to play pingpong and even a toy
piano!
Why bother?
Classical conditioning and operant conditioning are both
examples of ASSOCIATIVE LEARNING (the animal
LEARNS to associate a stimulus/action with a reward, the
reinforcer)
This may increase the chance of an animal’s survival and
reproductive success
Eg: an insect eating bird eats a wasp
BAD!
So … yellow and black =
best not tasted!
Kohler
Problem solving
http://www.youtube.com/watch?v=ySMh
1mBi3cI&feature=related
Pigeon
http://www.youtube.com/watch?v=mDnt
bGRPeEU
After trial and error, Sultan
was able to link two rods
together and use them to get a
banana
CAREFUL – anecdotes – not
under the rigours of Scientific
enquiry