Transcript 11 Animal_Behaviourx

Animal Behaviour
Area of Study: Adaptations of Animals
Animal behaviour – key knowledge
 Adaptations of animals include
behaviours, characteristics that increase
individual’s chance of survival and
reproduction.
 Animals forage or hunt for food, fight for
resources, defend territories, raise
offspring and live in social groups.
 Some behaviours are innate (instinctive)
and others are learned.
What is behaviour?
Behaviour refers to the coordinated activities of an
animal that are reproduced in response to internal or
external stimuli.
 Individual behaviour = Includes those related to
movement or physiological regulation (eg. dogs panting
when hot).
 Social behaviour = Related to interactions with other
organisms (eg. bees in a hive). Social behaviours are
related to courtship, reproduction and parenting;
feeding and defence strategies; and communication
within and between groups of animals.
What is behaviour?
Behaviour refers to
the coordinated
activities of an animal
that are reproduced in
response to internal or
external stimuli.
 Individual
 Social
Behaviour depends on detecting a
stimulus
 Behaviour depends on the detection of
internal or external stimuli by sensory
organs and the transmission of this
information through the nervous system.
Behaviour depends on detecting a
stimulus
 As a result of
natural selection,
patterns of
behaviour that
increase the
survival and
successful
reproduction of
individuals have
evolved.
Behaviour depends on detecting a
stimulus
 Spitfires live in
groups throughout
the day, emerging
from their bundle
of bodies to feed
on young leaves
under the cover of
darkness.
Behaviour depends on detecting a
stimulus
 What
environmental
stimulus causes
them to huddle
together?
Behaviour depends on detecting a
stimulus
 How could natural
selection have led
to the evolution of
this behaviour?
Inborn or learned behaviour
 Some behaviours are
innate (inborn) and
some are learned.
 It is an
oversimplification to
divide behaviour into
two discrete categories
– innate (genetic) and
learned
(environmental).
Inborn or learned behaviour
 Even the most rigid and
automatic behaviours are
affected by
environmental conditions,
and learning has a distinct
genetic component.
 Observable behaviour
ranges between highly
instinctive patters (such
as web-building) and
highly learned (such as
house building by
humans).
Question
 Youtube video of a spider
spinning a web
 Spiders know how to spin
webs instinctively. Can they
learn how to make a better
one as well? What advantage
does this innate ability to
build a web have on a
spider’s chance of survival
and reproductive success?
Innate behaviour
 Innate behaviour
eliminates the timeconsuming process of
learning, and may allow
rapid response.
 Generally any behaviour
that is not learned.
 Advantage – it can be
produced the first time –
no practice needed.
Innate behaviour
 Produced by a particular
inherited pattern of
organisation of nerve cells
in the nervous system,
occurring automatically in
response to a specific
stimulus.
 Instinct is the innate ability
to complete a specific
behaviour pattern; no
conscious intention is
involved.
Question
 Youtube video about flirting
 What do you think? Is flirting innate or learnt?
 Why does it not begin in most people until their teenage
years?
Releasers are signal signs
 Innate behaviour occurs
in response to specific
signals, called sign
stimuli or releasers.
 The degree of
responsiveness of an
animal to a releaser may
vary according to
particular environmental
conditions, such as the
time of day or season of
the year.
Releasers are signal signs
 Innate behaviour occurs in
response to specific signals,
called sign stimuli or
releasers.
 Male sparrows show
territorial behaviour (and
sing incessantly) in spring
when their testosterone
levels are high.
 The increase hormone level
is the results of nights
becoming shorter as spring
approaches.
Releasers are signal signs
 Releasers may also
involve other senses;
 sound (hens respond to the
sound of their chicks
distress calls, not the sight
of chicks in trouble)
 chemical (pheromones
that stimulate mating in
insects)
Question
 Youtube video about migration
 At a certain time in the year
Frigate birds, Boobies and
Green Turtles travel thousands
of kilometers to their breeding
grounds on Ascension Island.
Describe how releasers might
affect the expression of this
innate behaviour.
Question
 Find another example of migration in
animals and identify the releaser.
Releasers initiate behaviour
automatically
 From birth, herring gull
chicks peck at a red spot on
their parent’s bill in order to
get food. They will also
readily peck at red dots on
the end of a wagging pencil,
and a wagging model with
the red spot on its head.
Herring gull chicks respond
poorly to stationary models
and models with no spot.
Releasers initiate behaviour
automatically
 Silhouettes of predatory
birds trigger escape
responses in their prey. This
can be unlearnt.
Releasers initiate behaviour
automatically
 Fixed action patterns are
innate behavioural responses
that are particularly strong
and once triggered, proceed
to completion regardless of
any other input.
 Nipple finding behaviour in
babies,
 feeding of young in birds and
 egg-rolling by geese.
Releasers initiate behaviour
automatically
 Fixed action patterns are
innate behavioural responses
that are particularly strong
and once triggered, proceed
to completion regardless of
any other input.
 Nipple finding behaviour in
babies,
 feeding of young in birds and
 egg-rolling by geese.
Releasers initiate behaviour
automatically
 Fixed action patterns are
innate behavioural responses
that are particularly strong
and once triggered, proceed
to completion regardless of
any other input.
 Nipple finding behaviour in
babies,
 feeding of young in birds and
 egg-rolling by geese.
Releasers initiate behaviour
automatically
 Fixed action patterns are innate behavioural responses
that are particularly strong and once triggered, proceed
to completion regardless of any other input.
Stimulus
Nipple finding
behaviour in
babies
feeding of young
in birds
egg-rolling by
geese
Behaviour
pattern
Evolutionary
significance
Learning
 Many behaviours have
a significant
component that is
learned.
 It allows the
modification of a
behavioural response
to a particular
stimulus on the basis
of previous
experience.
 Wikipedia ref
Learning
 Many behaviours have
a significant
component that is
learned.
 Learning depends on
memory – the ability to
store and retrieve
information about past
events.
 Wikipedia ref
Learning
 Learning provides
flexibility, allowing an
animal to change its
behaviour in response to
unpredictable changes.
Question
Contrast the following in terms of the
advantages they provide to a individual’s or
species’ survival and reproductive success
using the information in these notes…
1. Innate behaviour in animals
2. Learnt behaviour in animals
What types of animals learn?
 All animals
 Learning and intelligence:
 Among vertebrates, the ability to learn is
sometimes taken as an indication of
intelligence.
 Octopuses, in particular, have highly
developed sensory organs, particularly their
eyes, which have the same structure and
operate in a similar way to vertebrate eyes.
What types of animals learn?
 Learning depends on
 The ability to detect change
 The ability to understand that change
 The ability to change the way the
organism behaves… and sometimes…
 The ability of a species to communicate to
one another.
Learning examples
 Youtube video of an octopus hatching and later learning
how to open a jar to get a meal.
 Youtube video of crows learning how to open
particularly tricky nuts
Question
 Youtube video of communal nest building birds
 Is the social nest building of these birds innate or learnt
behaviour or a mixture of both?
Types of learning
 Imprinting - Imprinting is the term used in psychology and
ethology to describe any learning which occurs at a particular
age or a particular life stage that is rapid and apparently
independent of the consequences of behavior. (ref)
 Habituation - the gradual fading of a response (usually an
innate response) to a stimulus that proves to be safe or
irrelevant.
 Associative learning (conditioning)  Trial and error learning –
 Observational  Insight -
Imprinting
 In some animals, the capacity for
learning about a particular stimulus is
very high at certain stages of
development.
 The period in which imprinting can occur
is quite short and usually occurs early in
life.
 learning that occurs during imprinting is
rapid and cannot be reversed.
Imprinting
 For example, ducklings
begin walking within
hours of hatching and
‘imprint’ on their
mother; that is, they
follow her wherever she
goes.
Question
 Identify: How could
imprinting benefit the
reproductive success of
individuals and / or the
survival of the species?
Question
 Youtube video about Konrad Lorenz and imprinting
 Discuss: Adopted children often feel a real urge to find
their real parents once they grow up and experience an
enormous relief when they do. Do you think that
imprinting is different in humans to animals? Discuss.
Habituation
TODAY
TOMORROW
NEXT WEEK
 A scarecrow might initially frighten birds away from a
fruit crop, but before long the birds are likely to be
seen perched on the scarecrow’s shoulders. Fish in a
tank will quickly learn to ignore repeated tapping on
their tank and overhead shadows caused by a waving
hand. These behaviours are examples of habituation,
which is the simplest and most common form of
learning.
Habituation
 The ability to get used to a repeated
stimulus, such as noise, is called
habituation.
Habituation
 Habituation involves gradual fading of a
response (usually an innate response) to
a stimulus that proves to be safe or
irrelevant.
Habituation
 The stimulus is initially unfamiliar and
the response is defensive, such as startle
or escape response.
Habituation
 After repeated stimulation, the
magnitude of the response becomes less
and less.
 The advantage of habituation is that an
individual does not waste time and
energy reacting defensively where there
is no danger.
Question
 Youtube video showing how a rat learns not to be
startled by a loud noise.
 Discuss: what examples of habituation in humans do you
know of?
Associative learning
 Example: pets, Pavlov’s dogs.
 Associative learning (also known as classical
conditioning) involves the association of a
new signal with the innate signal that
triggers a particular behavioural response.
 Just as associative learning can be induced,
so it can be lost again if the association
between the two signal disappears. This
loss of learning is called extinction.
Question
 Youtube video explaining Pavlov’s original experiments.
 Youtube video explaining how Pavlov’s experiments with
dogs can help us understand human reactions to mobile
phone ringing.
 Discuss: what you do when a mobile phone rings. Do you
do this for every type of ring?
Trial-and-error learning
 In this form of learning an animal carries
out a particular behaviour and,
remembering the attempt and its outcomes,
modifies its subsequent behaviour in order
to improve the chances of success.
 The animal learns from its mistakes.
 Trial-and-error learning involves refining
behaviour to suit a particular set of
environmental conditions.
 Observational learning
 Many higher vertebrates, particularly
birds and animals, can learn particular
patterns of behaviour by observing other
animals.
 Most likely gained from parents and peers.
 It is the means by which cultural
information is transferred from individual
to individual, and from generation to
generation.
 Insight learning
 the most complex kind of learning.
 requires complex brains like those found in some
mammals, such as dolphins and the great apes (including
humans).
 A problem is solved as the result of thinking about it rather
than by trial and error.
 It is related to the ability of an animal to apply past
experience to solving a new problem without a trial-anderror period.
 Involves the use of reason.
 Play forms an important part in developing problem-solving
skills for later use.
Behaviour for maintenance
 The basic behaviour patterns of individual animals
enable them to meet their requirements for surviving
and maintaining their well being.
 Maintenance behaviours occupy much of an animal’s time.
 Includes activities such as feeding, drinking, ventilation,
finding or making shelter, regulating temperature, and
grooming.
 To catch food and avoid being eaten, animal consumers
show certain behavioural patterns (adaptations) that are of
benefit to their survival.
Behaviour for maintenance
 Patterns of behaviour are generally adaptive; that is
they are of benefit to the individual organism.
 Animals must divide their time between these
different activities.
 Often it is necessary to change from one behaviour to
another when circumstances change (eg. from eating
to fleeing if a predator approaches).
 A particular behaviour will also depend on the
physiological state of the animal (eg. a hungry
jumping spider is more likely to show predatory
behaviour than a well-fed one).
Rhythmic activities
 Periods of activity and inactivity
alternate in most animals, often on a
daily basis.
 Daily cycles are known as circadian
rhythms.
 Lunar cycles are cycles that coincide with
the waxing and waning of the moon.
 Tidal rhythms affect many organisms.
Rhythmic activities
 Circannual rhythms are yearly rhythms, eg.
migrations of some birds and whales, the
hibernations of animals during winter.
 Circadian rhythms are biological clocks. They
are internal timers that operate in the absence
on any external cues.
 In vertebrates, ‘clocks’ are usually synchronised by the day/night
cycle of light intensity. At night, in the absence of bright light,
the hormone melatonin is produced by the pineal gland. Blood
levels of this hormone fall when light enters the eyes. The level
of melatonin in the blood therefore reflects the time of day. The
cycle of its increasing and decreasing level indicates the length
of the night and thus the season.
Movement
 Animals move to obtain food, seek shelter,
interact with other animals and seek out
mates.
 Aquatic animals move about using cilia, flagella,
tentacles, fins or flippers.
 Bivalve molluscs clap their shells together and
octopuses and squids use jet propulsion for rapid
escape.
 Terrestrial animals crawl, walk, run, tunnel
through the ground, or fly or glide through the
air.
Feeding behaviour
 Herbivores and predators know what
to eat, where to find food, how to get
it, and how to eat it.
 Feeding behaviour is an example of a
rhythmic behaviour.
Feeding behaviour
 Feeding may be:
 On an individual basis (eg. spider)
 On a group basis, in which members of a species
cooperate in some way to improve their chances
of obtaining food (eg. humpback whales using
bubble net feeding, common dolphins).
Feeding behaviour
 Adaptations for feeding include physical
characteristics, such as a carnivore’s sharp
teeth for killing and tearing meat, but also
behaviours for getting food.
 Many animals, particularly carnivores, spend a
lot of time resting, which conserves energy in
between hunting trips.
 Herbivores, such as koalas, often spend a large
part of their day eating and chewing because
plant fibre require considerable chewing and
long periods in the gut for complete digestion.
Defensive behaviour
 Searching for food runs the risk of exposure to
predation during feeding.
 Some animals ward off potential predators.
For example:
 The venomous blue-ringed octopus quickly develops
characteristic brilliant blue rings on its tentacles as a warning
sign when disturbed.
 When alarmed the rattlesnake makes a rattling noise with the
end of its tail.
 Caterpillars have various defence mechanisms; some are well
camouflaged and hide during the day; others taste bad and
are covered with long defensive hairs.
Homeostatic behaviour
 Maintenance behaviours include those that
contribute to the homeostatic control of the
internal environment, including water balance and
temperature.
 In many land vertebrates, fluctuations in internal
body temperature are reduced by various
behaviours. For example the behaviours of desert
lizards include:
 Panting
 Changing body posture and orientation
 Moving into and out of shelter
 Nocturnal activity.
Grooming and preening
 Many animals clean the outer surface
of their bodies.
 Grooming of fur by cats, tigers and lions.
Grooming and preening
 Preening of feathers is essential
for the survival of birds.
 It involves spreading oil from a
gland at the base of the tail over
the feathers that may have become
ruffled, reuniting the hooks and
hooklets of feathers.
 This maintains their aerodynamic
properties.
Home-building
 Some animals do not
make or find homes,
but some construct
elaborate structures.
For example:
 Termite nests
 Ant nests
 Beehives
 Spider webs
 Rabbit burrows
 Bird nests
 In the case of a
spider weaving its
web, selection of
building materials
and construction of
the web do not
involve learned
behaviour, but
learning is
fundamental to the
construction of
homes by humans.
Territorial behaviour
 Many animals are territorial, meaning that
they defend a certain area (territory) that
contains a limited resource against
occupation by other animals.
 The boundaries of territories are patrolled,
marked by scent and, in birds, indicated by
singing.
 Territories are often defended aggressively.
Territorial behaviour
 The area over which an animal forages for food is its
home range.
 Sometimes an animal’s territory and home range are the
same, but more often an animal will defend only a part
of its home range, usually around its den or nest.
 The advantage of this kind of behaviour to the
individual is that a resource in a successfully defended
territory does not have to be shared, and direct
competition between individuals is reduced. However
the animal must also expend energy and time defending
its area.
Communication and social behaviour
 Communication is the transfer of
information from one animal to
another.
 The message or signal, which can be
chemical, auditory, tactile, or visual,
is passed between a sender and a
receiver.
 Communication usually occurs
between members of the same species
and is often associated with
reproductive behaviour and with other
social interactions within a group.
Communication and social behaviour
 Communication between species occurs less frequently. It
may be aggressive, defensive or cooperative.
 The important components of communication include:
 Stimulus for the communication
 Sender of a signal
 Receiver to whom the signal is directed
 The kind of signal sent
 How the signal is sent
 The behaviour of the receiver
 The setting in which the communication occurs.
The making of a bower by a male bowerbird is a
behavioural response to a particular stimulus. His
behaviour sends a signal to female bowerbirds.
Aspect of communication
Particular case with bowerbird
Stimulus
Desire to mate
Sender
Male bowerbird
Receiver to whom the signal is directed
Female ready to mate
Kind of signal
Appearance of carefully made and
decorated bower
How the signal is sent
Visual image
Behaviour of receiver
Attracted to the bower
Setting in which the communication
occurs
Courtship behaviour
Communication and social behaviour
 Some animals gain an advantage by
mimicking the appearance and
behaviour of another species.
 Many species use striking colouration
or calling signal to communicate with
a potential mate.
Chemical communication by
pheromones
 Probably the most primitive and universally
used form of communication.
 Chemical communication is the release of
chemicals into the environment that transmit
information to those animals that have the
appropriate receptors for receiving the
chemical signal.
 Chemical that carry messages between
individuals of the same species are known as
pheromones.
Visual signals
 Visual communication is instantaneous and
can carry a large amount of information.
 Highly directional and the sender can be
immediately identified.
 The message may be continuous, eg. birds
where the plumage of males and females is
strikingly different.
 Very few species rely solely on visual signals
for communication.
Sounds as signals
 Auditory communication can be used in the dark, and
‘around corners’.
 It is faster than chemical communication and can carry
lengthy and complex messages.
 Sounds can carry a great deal of information if the
pattern, frequency and pitch are varied.
 Auditory communication requires complex soundemitting and receiving organs, and is therefore found in
animals with well-developed nervous systems.
Sounds as signals
 Used by most vertebrates, many insects and
some marine arthropods.
 For example, sperm whales live in families
of 10-12 individuals, including mothers,
daughter, aunts and young males. They
communicate in a language of clicks and
pauses.
 The most complex example of auditory
communication is human speech.
Communication by touch
 Tactile communication (communication by
touch) is found more frequently in highly
social groups of animals, such as ants, some
birds and mammals.
 It can only occur between individuals in
close proximity.
 The message is simple and does not require
specialised sensory organs.
Social behaviour
 Communication is most important in the
lives of animals that form cooperative
groups, known as societies.
 Social behaviour involves interactions
between members of a group.
 Social behaviour can improve the defence
of limited resources, foraging ability,
surveillance and defence against predators
and care of offspring.
Social behaviour
 An important aspect of the social cohesiveness of the
group is efficient two-way communication between its
members.
 Social interactions may involve cooperation as in mating
or ensuring a food source.
 Competition between individuals of the same species
for resources often results in contests between
individuals.
 Social behaviours may involve aggression and conflict as
individuals or groups fight to defend territories or to
select a mate.
Social behaviour
 In certain species the behaviour of some
individuals in a social group is dominated by
other individuals.
 Dominance means that one individual has greater access to
resources, such as food or mates, than other individuals in
the group.
 There may be a hierarchy of dominance – an individual’s
position is often signalled by aggressive or submissive
behaviours.
 The most dominant individual is often a male, who eats
first and has first choice of mates.
Culture
 Cultural exchange
is the passage of
information from
generation to
generation by nongenetic means.
Cultural learning
involves activities
such as:
 selecting and preparing
food;
 catching prey;
 recognising enemies;
 defence;
 learning songs;
 migratory routes;
 bonding behaviour;
 courtship; and
 reproductive behaviour.