Week 20

Question 1

Which of the following best describes the sampling method ‘Focal Sampling’?

Answer 1

Sampling focuses on one animal for a period of time and you record all behaviours.

Question 2

Which of the following best describes the sampling method ‘Scan Sampling’?

Answer 2

The behaviour of one or more individuals is recorded at time intervals.

Question 3

Which of the following best describes the ‘continuous recording rule’?

Answer 3

The observer records the exact time and duration that the behaviour occurs

Question 4

Which of the below would be the best behavoiur name for the definition ‘Threatening, chasing, hitting, biting another individual’?

Answer 4

Aggression

Question 5

Which of the below does NOT describe one of ‘Tinbergen’s four questions’?

Answer 5

Physicality

Question 6

What is the definition of ‘innate behaviour’?

Answer 6

Behaviour that is thought to be caused by genes within the nervous system with little influence from the environment.

Question 7

What are the neuropeptides that cause prairie voles to form pair bonds?

Answer 7

Oxytocin and Vasopressin

Question 8

The presentation of two different kinds of stimuli causing an animal to form an association between two stimuli is known as:

Answer 8

Associative conditioning

Question 9

Which of the following accurately describe the observable response of organisms to their environment?

Answer 9

Behavior

Question 10

Specific genetic and physiological mechanisms that produce a behavior are called _____ causes of the behavior.

Answer 10

Blank 1: proximate

Question 11

Which of the following is not a proximate causation of behavior?

Answer 11

A male bird sings because singing allows it to defend a territory and attract females.

Question 12

When you consider causes of behavior, which of the following are correctly matched?

Answer 12

Proximate causes: mechanisms that underlie behavior

Ultimate causes: evolutionary explanation for behavior

Question 13

Even though they might be very complex, behavioral traits are subject to evolution through ______ ______.

Answer 13

Blank 1: natural

Blank 2: selection

Question 14

Behavior is the observable response of organisms to their

Answer 14

Blank 1: environment, surroundings, or niche

Question 15

Proximate causes of behavior are best described as which of the following?

Answer 15

Specific genetic and physiological mechanisms of behavior

Question 16

In a 40 year study of captive foxes in Siberia, scientists have been able to breed foxes that behave more like domestic dogs than wild foxes. This long-term experiment has demonstrated that ______.

Answer 16

behavioral traits can evolve through artificial selection

Question 17

During the spring, increased levels of testosterone are necessary for a male songbird to sing; this is an example of ______ causation of behavior.

Answer 17

proximate

Question 18

When a human approaches a Montagu’s harrier nest, birds react in one of two ways: they either leave immediately, or they remain and react aggressively. In places where humans are common, birds that react aggressively raise more offspring. When one such area was studied for 19 years, the proportion of birds that act aggressively significantly increased. This result suggests that the harriers’ behavior ______.

Answer 18

can be affected by natural selection because it is heritable and affects fitness

Question 19

Mechanisms underlying a specific behavior are known as _______
causes of that behavior; in contrast, answering the question why this behavior evolved allows us to determine its _______
causation.

Answer 19

proximate

ultimate

Question 20

In which of the following situations is an organism exhibiting territoriality?

Answer 20

When it defends a portion of its home range and uses it and its resources exclusively

Question 21

Which of the following statements accurately describes the evolution of behavioral traits?

Answer 21

Behavioral traits can evolve by natural selection as long as they exhibit variation, are heritable, and can affect fitness.

Question 22

The defining characteristic of territorial behavior is ______
against intrusion and resource use by other individuals.

Answer 22

Blank 1: defense, protection, or guarding

Question 23

Which of the following are examples of the costs of territorial behavior in songbirds?

Answer 23

A bird must expend energy to sing.
A bird may be more vulnerable to predators while singing.
A bird may be injured when being aggressive towards another bird.

Question 24

Studies with fruit flies have demonstrated the behavioral traits can be altered by artificial selection because

Answer 24

scientists have been able to breed fruit flies that prefer to fly upwards when presented with a choice in a maze.

Question 25

What are examples of natural selection causing changes in the behavior in animals?

Answer 25

In ares where human presence is common, most of the harriers remain in their nest and react aggressively to approaching humans.

Bighorn sheep have evolved to be bolder in areas with higher mountain lion densities.

Question 26

When an individual defends a portion of its home range and uses it and its resources exclusively, the individual is exhibiting _______ behavior.

Answer 26

Blank 1: territorial

Question 27

Which of the following is the defining feature of territorial behavior?

Answer 27

Defense against intrusion and resource use by other individuals

Question 28

One cost of territorial behavior is the large amount of ______ that has to be expended for displays.

Answer 28

Blank 1: energy

Question 29

Typically territories are defended in two ways: by _____ advertising that the territory is occupied and/or by overt _____

Answer 29

Blank 1: displays, behavior, or displaying

Blank 2: aggression, hostility, or violence

Question 30

Increased access to food due to the exclusive use of a patch of habitat is one of the benefits of ______.

Answer 30

Blank 1: territoriality

Question 31

In which of the following situations is an organism exhibiting territoriality?

Answer 31

When it defends a portion of its home range and uses it and its resources exclusively

Question 32

Territorial behavior will typically evolve if holding a territory provides ______
to the animals that exceed the _______
of holding that territory.

Answer 32

Blank 1: benefits, gains, advantages, or profits

Blank 2: costs, cost, or price

Question 33

What are the the two basic types of territorial behavior?

Answer 33

Display behavior that shows that a territory is occupied

Aggressive behavior against intruders

Question 34

Which of the following is not a benefit of territoriality?

Answer 34

Increased competition for food

Question 35

When does territorial behavior typically evolve?

Answer 35

When the benefits of holding a territory outweigh the costs of holding it

Question 36

What is the study of animal behaviour?

Answer 36

Observing behaviour gives us insights into…

• The workings of the brain
• Influences of genes and the environment
• When and how animals reproduce
• How they adapt to their environment

How behavioural biology helps us understand the mechanisms that underscore evolution.
The study of behaviour is the centre of many disciplines of biology. Observing behaviour provides important insights into the workings of the brain and the nervous system, the influences of genes and the environment, when and how animals reproduce, and how they adapt to their environment. Behaviour is shaped by natural selection and is controlled by internal mechanisms involving genes, hormones and neurotransmitters and neural circuits.
In this short series of lectures, we’re going to see how behavioural biology helps us understand the mechanisms that underscore behaviour and its evolution.

Question 37

Definition of behaviour:

Answer 37

• Behaviour is the way an animal responds to its environment by tracking cues and signals from its environment.
• Behaviour allows an animal to survive and reproduce so it’s central to the evolutionary process.

-Behaviour is what an animal does. The way an animal responds to its environment by tracking cues and signals such as odours, sounds and visual signals from its environment, associated with food, predators or mates. Behaviour also concerns thinking and cognition as well as monitoring one’s social environment. Behaviour allows an animal to survive and reproduce, and so is central to the evolutionary process.

Question 38

Why and how does an animal behave the way it does?

Answer 38

Proximate and Ultimate causes of behaviour

•Proximate causation
- The mechanisms that produce the behaviour
Proximate causation of behaviour involves the immediate mechanisms that bring about an action.

•Ultimate causation
- Why this behaviour has evolved.
Ultimate causation refers to the adaptive value of behaviour.

Question 39

Why does an animal behaviour the way it does?

Answer 39

Think about the example of a bird song. We can ask questions about how and why the bird sings.
How type questions relate to proximate causation – the mechanisms that produce the behaviour. We consider the role of internal factors such as hormones, nerve cells and other physiological processes. To analyse the proximate cause of birdsong, we could measure hormone levels or study the development of brain regions and neural circuits associated with singing.
Why type questions, relate to ultimate causation – why this behaviour has evolved, and is the evolutionary explanation for why birds sing. So we could analyse whether a male bird sings to defend a territory from other males or to attract a female.
We often study behaviour from both perspectives to fully appreciate both the mechanisms and function of behaviour, and thus its role in evolution.
Mechanisms are related to the proximate causation- how type questions and the function of behaviour is related to the ultimate causation and the why type questions.

Question 40

What are Tinbergen’s four questions?

Answer 40

Tinbergen’s four questions, named after Nikolaas Tinbergen and coined in the early 1960s are complementary categories of explanations for animal behaviour.

Behaviour can be measured at four levels.

1. Physiology – how it is influenced by hormones, nerve cells and other internal factors. How does the trait work- what is the mechanism behind that behaviour.
2. Ontogeny – how it develops in an individual across its life span.
3. Phylogeny – its origin in groups of related species- how did the trait evolve? How did the behaviour evolve and why did the behaviour evolve?
4. Adaptive significance – its role in survival and fitness. Why was the behaviour able to persist?

Question 41

How is behaviour determined?

Answer 41

Ethologists are biologists who study behaviour.
Innate behaviour: behaviour that’s genetically hardwired in an organism and can be performed in response to a cue without prior experience.

Ethologists were biologists who first began to study the natural history of behaviour at the beginning of the 20th century.
Ethologists observed that individuals from a given species behave in stereotypical ways – showing the same pattern of behaviour, to a given stimulus.
Innate behaviour – was behaviour that seemed instinctive, where behaviour is stimulated by a key stimulus and thought to be programmed by the nervous system which was designed by genes. Some examples include spiders spinning webs, bird building a nest, caterpillars making cocoons and dolphins leaping from the water.

Question 42

Neuroethologists -

Answer 42

– biologists who examine the neurobiology of behaviour.
Behaviour reflects the organisation of the peripheral and central nervous systems.
Studying behaviour helps us understand how neurons function.

Neuroethologists, are biologists who examine the neurobiology of behaviour, can describe in detail how information in the environment is processed by sensory cells, and how nerve impulses are transmitted to other neurons and muscles to form neural circuits that regulate behaviours important to survival.
Behaviour reflects the organisation of the peripheral and central nervous systems and studying behaviour can help us understand how neurons function individually and in combination with other neurons in circuits.

Example – some behaviours must occur rapidly, and neural mechanisms enable such functions. For example, in the ‘trap jaw’ ants, large axons of the mandibular motor neuron (the fastest neuron yet identified) fire nerve impulses that close the jaws in only 33 milliseconds.

Question 43

Examining the relationship between hormones and behaviour helps us understand the endocrine mechanisms that underly:

Answer 43

• Reproduction
• Parental care
• Aggression
• Stress

Testosterone: territorial behaviour
Oestrogen: mating behaviour
Glucocorticoid: stress

Behavioural biologists also examine the relationships between hormones and behaviour to understand the endocrine mechanisms that underlie reproduction, parental care, aggression and stress. E.g. Testosterone in the male regulates territorial behaviour and courtship. Oestrogen in the female controls her mating behaviour. Glucocorticoid hormones are involved in stress.

Question 44

What are neurotransmitters and how can we measure them?

Answer 44

Neurotransmitters: molecules used by the nervous system to transmit messages between neurons or from neurons to muscles.

We can measure the levels of neurotransmitters and associate the chemicals with behaviour.

Example: Serotonin has been shown to influence aggression in lobsters, mice and humans.

Neurotransmitters are often referred to as the body’s chemical messengers. They are the molecules used by the nervous system to transmit messages between neurons, or from neurons to muscles. Communication between two neurons happens in the synaptic cleft (the small gap between the synapses of neurons).

We can also measure levels of neurotransmitters such as serotonin and dopamine in the nervous system or blood and associate these chemicals with behaviour. Serotonin has been shown to influence aggression (e.g. lobsters, mice, humans).

Question 45

Nature v Nurture

Answer 45

Nature- Genes and hereditary factors- physical appearance, personality characteristics.

Nurture- Environmental variables, childhood experiences, how we were raised, social relationships, surrounding culture.

Is behaviour determined more by an individual’s genes (nature) or by its learning and experience (nurture)?
The problem with this question and this debate, is that both instinct and experience have significant roles, and interact to shape behaviour.

Question 46

What are Behavioural genetics?

Answer 46

1. Behavioural genetics: the contribution that genes make to behaviour.
2. Behavioural differences among individuals result from genetic differences.

Let’s first look at the role of genes in behaviour.

Behavioural genetics deals with the contribution that genes make to behaviour.
Pioneering research indicated that behavioural differences among individuals result from genetic differences.
Research on a variety of animals suggested that hybrids showed behaviours that were intermediate between those of their parents, as would be expected given that hybrids have genes from both parents.
These early efforts to define the role of genes in behaviour. Demonstrated behaviour can have a heritable component.

Question 47

What is an example of learning that can be influenced by genes?

Answer 47

Learning itself can be influenced by genes.

Let’s look at an example.

Rats had to find their way through a maze of blind alleys to the single exit, where a reward of food awaited them.
Some rats quickly learned the route to the food and other rats made many errors in learning the correct path. Fast rat population and the slow rat population- those who made errors when learning.
Researchers bred rats that made few errors with one another ‘maze-bright’ group, and rats that made lots of errors in the ‘maze-dull’ group.
Offspring from each group were then tested in their maze learning ability.

Here are the results.

The offspring of maze bright rats learned with even fewer errors than their parents, whilst offspring of maze-dull parents performed more poorly than their parents.
Repeating this artificial selection for a few generations, led to two behaviourally distinct sets of rat showing natural selection can shape behaviour over time, making genes for certain abilities more prevalent. - showing NS shapes behaviour over time.
The further you are along to the right hand side on the x-axis the more errors those offspring were making in the maze, further to the left of the axis the less errors that the offspring were making in the maze.

Question 48

What has allowed us to Identifying single genes that control behaviour?

Answer 48

Molecular biology

Question 49

What is an example of molecular biology?

Answer 49

Molecular biology has allowed us to identify the actual genes involved in behaviour, in animals ranging from fruit flies (Drosophilia) and mice to humans.

Example: Single genes can play a role in maternal care
fosB gene determines whether female mice nurture their young effectively.
In mice normal mothers take good care of their offspring, retrieving them if they move away and crouching over them and mice that do not have this fosB gene tend to not collect their young when they move away and do not crouch over them.

– single genes can play a role in behaviours as complex as maternal care.
fosB gene determines whether female mice nurture their young effectively.
in mice, normal mothers take very good care of their offspring, retrieving them if they move away and crouch over them.Mothers with fosB allele inactivated spent less time crouching over offspring and less time retrieving pups.

Mothers with the mutant fosB allele perform neither of these behaviours, leaving their pup exposed.
Females with both fosB alleles disabled initially investigate their newborn babies, but then ignore them, when they should show care and protective maternal behaviour.

Question 50

What does inattentiveness in mice show?

Answer 50

The inattentiveness seems to come from a chain reaction:

When mothers inspect new born babies, information from their auditory, olfactory and tactile senses is transmitted to the hypothalamus, where fosB alleles are activated.
The fosB alleles produce a protein, which in turn activates other enzymes and genes that affect the neural circuitry of the hypothalamus.
These modifications in the brain cause the female to behave maternally.

If mothers lack the fosB allele, this process stops halfway. No protein activated, the brains neural circuitry not rewired and no maternal behaviour. Maternal instincts of mice can be defined genetically and this is all down to the fosB allele.

Question 51

________ and _______ are involved in the expression of pair bonding

Answer 51

Neuropeptides Oxytocin

Vasopressin

Question 52

What is an example of genetic basis?

Answer 52

Another example of the genetic basis of behaviour is with prairie and montane voles, two closely related species of North American rodent that differ profoundly in their social behaviour.
Male and female prairie voles form monogamous pair bonds and share parental care.
Male and female montane voles are promiscuous (mate with multiple partners and go their separate ways).
The act of mating releases neuropeptides vasopressin and oxytocin, and causes prairie volves to form pair bonds but montane voles are unaffected.
The prairie vole has many receptors for these neuropeptides in a particular part of the brain (nucleus accumbent) which seems to be involved in the expression of pair-bonding behaviour.
Montane voles have very few of these receptors.
The vasopressin receptor gene, for human males, has been recently found to be associated with the strength of marital bonds and satisfaction in marriage.

Question 53

How is behaviour determined?

Answer 53

Learning

Definition of learning: Behaviour which is developed from previous experience. Behaviour can also develop from previous experiences, a process termed learning.

Question 54

What is an example of a learning mechanism?

Answer 54

Habituation – a decrease in response to a repeated stimulus.
Habituation can have adaptive value.
Example: Prey defence

Habituation is a simple form of learning defined as a decrease in response to a repeated stimulus that has no positive or negative consequences.The stimulus may initially create a strong response, but this will decline with repeated exposure.

Example: An ecological context where habituation has adaptive value is prey defence. Birds that feed on insects search for suitable prey in a visually complex environment. Insects that have camouflaged bodies appear to be twigs or leaves. Because birds see objects frequently, they habituate to their appearance. Insects that look like twigs or leaves are therefore protected because they do not trigger an attack and they survive to reproduce.

Question 55

What is associative learning?

Answer 55

Associative learning – behaviour is conditioned through association.

Associative learning – behaviour is modified, or conditioned, through association. The two major types of associative learning are classical conditioning and operant conditioning.

Question 56

What are the two types of associative learning?

Answer 56

Two major types:

1. Classical conditioning
2. Operant conditioning.

Learning provides flexibility that allows behaviour to be fine-tuned to the environment.

More complex forms of learning concern changes in behaviour through an association between two stimuli or a stimulus and a response.

Question 57

Classical versus operant conditioning.

Answer 57

Classical- Associate an involuntary response and a stimulus

Operant conditioning- associate a volutary behaviour and a consequence8i

Question 58

What is an example of classical conditioning?

Answer 58

Classical conditioning, also known as Pavlovian conditioning, after the Russian psychologist Ivan Pavlov. – this is where the paired presentation of two different kinds of stimuli causes the animal to form an association between the stimuli.

Example: Pavlov presented meat powder (unconditioned stimulus) to a dog and noted that the dog responded by salivating, an unconditioned response. If an unrelated stimulus such as the ringing of a bell was repeatedly presented at the same time as the meat powder, the dog would salivate in response to the bell alone. The dog had learned to associate the unrelated sound stimulus with the meat powder stimulus. The response to the sound stimulus was conditioned.

Question 59

What is an example of operant conditioning?

Answer 59

Operant conditioning – an animal learns to associate its behaviour with reward or punishment.

Example – American psychologist B. F. Skinner studied this in rats by placing them in an apparatus later known as a ‘skinner’ box. If a rat pressed a lever in the box it would get a reward, some food. It soon learned to associate pressing the lever (the behavioural response) with obtaining the food (reward). This type of trial-and-error learning is important for most vertebrates.

Question 60

What are the predispositions of learning?

Answer 60

Animals have predispositions towards forming certain associations and not others. For example, pigeons can learn to associate food with colours, but not with sounds. But they can learn to associate danger with sounds, but not with colours.
This shows that what an animal can learn is biologically influenced. Learning is only possible within the boundaries set by evolution.
Innate programmes for learning have evolved because they lead to adaptive responses.
The seed a pigeon eats may have a distinctive colour that the pigeon can see, but makes no sound, so it makes sense the ability to associate illness from bad food with colour and not sound as evolved.

Question 61

• –______ is the study of behaviour, emphasising instinct and the regulation of behaviour by internal factors (genes, nerve cells, hormones)
• —______ ______ is thought to occur when key stimuli affect innate releasing mechanisms which trigger fixed motor programs.
• —______ ____ provided by hormones and by neurotransmitters such as serotonin and dopamine cause behaviours to occur.
• —A relationship between ____ and ______ has been demonstrated in many ways, including artificial selection experiments and studies on the effect of single genes.
• –Genes can regulate ______ by producing molecular factors that influence the function of the nervous system.

Answer 61

• -Ethology
• —Instinctual behaviour
• —Chemical signals
• –genes and behaviour
• –behaviour

Question 62

As we have seen, behaviour has both ____ and learned _____. So far we have discussed these separately, but these two factors interact during development to shape behaviour.

Answer 62

genetic

components

Question 63

What is imprinting?

Answer 63

Imprinting: Social attachments or preferences to other individuals
Filial imprinting: social attachment formed between parents and offspring
Ethologist: Karl Lorenz used himself as a model for imprinting.
As animals grow up, they may form social attachments to other individuals or develop preferences that will influence behaviour later in life.
Imprinting is this process of behavioural development.
The success of imprinting is highest during a critical period (e.g. 13-16 hours after hatching for geese). During this time, information required for normal development must be acquired.
Filial imprinting is the social attachment formed between parents and offspring. For example, young birds like ducks and geese follow their mother within a few hours after hatching and this creates a social bond between mother and young.
The ethologist Konrad Lorenz showed that geese will follow the first object they see after hatching and direct their social behaviour toward that object. Lorenz used himself as a model for imprinting and the goslings treated him like their mother and followed him dutifully.
Interactions between parents and offspring are key to the normal development of social behaviour.

Question 64

Song learning in white-crowned sparrows

Classic study on song learning

Answer 64

Zonotrichia leucophrys
Is song a result of innate programs, learning or both?

Experiment 1.
Male bird reared in soundproof incubators
-> Sang poor songs as adults
-> Instinct alone does not guide good song production.

Classic study by neurobiologist Peter Marler on song learning in white-crowned sparrows to show how innate programs and experience contribute to the development of behaviour.
Mature male white-crowned sparrows sing a species-specific courtship song during the mating season.
Marler asked whether the song was the result of an instinct, learning, or both.
He reared males birds in sound proof incubators to control what a bird heard as it matured, then recorded the song they made as an adult.
Males that heard no song at all during development sang poor songs as adults, showing instinct alone wasn’t enough for good song development.
This shows that instinct alone wasn’t good enough for some development.

Question 65

Song learning in white-crowned sparrows.

Answer 65

Classic study on song learning
Is song a result of innate programs, learning or both?

Experiment 2.
Males were played the song of a different species – the song sparrow.
-> Sang poor songs as adults
-> Males cannot imitate any song

Then, males were played the song of a different species, song-sparrow. These males sang a poorly structured song as well. This showed males would not imitate any song they learned.

Classic study on song learning
Is song a result of innate programs, learning or both?
Experiment 3.
Males were played the song of their own species
-> fully developed good songs as adults
-> males have a genetic template (innate program) that guides them to learn the appropriate song.

Birds that heard the song of their own species, sang fully developed songs as adults.
These results suggest males have a genetic template that guides them to learn the appropriate song. During a critical period, the template will accept the white-crowned sparrow song as a model.

Question 66

What is another aspect of Song learning in white-crowned sparrows?

Answer 66

Critical period -> genetic template will accept the white-crowned sparrow song as a model
Song acquisition depends on learning, but only the song of the correct species can be learned.
Limitation of the study: only tape-recordings used.

Thus, song acquisition depends on learning, but only the song of the correct species can be learned.
Learning is also important. The birds must hear the correct song during the critical period, and then practice, listening to themselves sing, in order to develop a good song.
Limitation of this study is that only tape-recordings were used, and if a real bird, such as strawberry finch, was placed next to the young sparrows, they can learn this different species song too.

Question 67

Animals can change their behaviour through _____.

Although learning mechanisms may be similar across species, animals also differ in their learning abilities according to their _____.

During the ____ period, offspring must engage in certain social interactions for normal behaviour development.

Answer 67

• -learning
• -ecology
• -critical

Question 68

_____, like any other feature of an adult animal, must develop from the interaction of genetically determined ______ with the environment in which the young animal grows up.

Answer 68

Behaviour

predispositions

Question 69

With behaviour, there is often a temptation to label its origins as either being _____ - _____ - or _____ as the result of experience.

Answer 69

inborn - inherited - or acquired

Question 70

What does the Montagu’s Harrier tell us about selective breeding?

Answer 70

Differ in their response to approaching threat – some remain, some fly away
The birds that stay on the nest raised more offspring
The birds that fled decreased by 75% over 19 year study.

-> natural selection favours one trait over another.

Researchers have also documented natural selection operating on behavioural differences among individuals in nature.
E.g. When sitting on a nest, Montagu’s harriers (hawk) differ in their response to approaching humans – some consistently remain and react aggressively, whereas others fly away. In one study the birds that remained on the nest raised more offspring, another example of natural selection favouring one behavioural trait over another.
Because differences such as these are often the result of genetic differences, such natural selection can lead to evolutionary change. Indeed, the proportion of birds that fled from approaching humans decreased by more than 75% over the 19 year study, as this was not an adaptive response.

Question 71

What also may have evolved twice?

Answer 71

Male transportation and attendance evolved first, and gradually females took over the duties in some clades.Also, tadpole feeding evolved convergently twice, once in an ancestral species in which the male did the transporting and the other time in a female-transporting ancestor.

Question 72

What is the adaptive function of behaviour?

Answer 72

-> How behaviour allows an animal to stay alive and keep it’s offspring alive.

Question 73

What are the two questions that are involved with behavioural ecology?

Answer 73

The field of behavioural ecology is concerned with two questions.
Is behaviour adaptive? This isn’t always the case, traits can appear for many reasons such as genetic drift. Traits may also be present in a population because they evolved as an adaptation in the past but are no longer useful.
If behaviour is adaptive, the next question is ‘how is it adaptive?’
The ultimate criterion is reproductive success but how does behaviour lead to greater reproductive success? Does a behaviour enhance energy intake (thus increasing the number of offspring than can be produced), does it decrease the chance of predation?

Question 74

Behavioural ecologists try to determine the effect of a behavioural trait on _____ and discover whether ______ in a certain behaviour mean an increase or decrease in _____.

Answer 74

activities
increases
fitness

Question 75

What is an example of adaptive behaviour?

Answer 75

A classic example – the adaptive value of egg coloration. Tinbergen observed that after gull nestlings hatch, the parents remove the egg shells from the nest. To understand why (ultimate cause) he painted chicken eggs to resemble gull eggs – these have camouflage colouration so they blend into the natural background.

Why?
Tinbergen painted chicken eggs to resemble gull eggs
Gull eggs -> camouflaged

Broken painted shells
Broken shells with white exposed
Not-broken shells

He spread these throughout the area where the gulls were nesting, placing broken egg shells with prominent white colour next to some of the eggs, and as a control, left some eggs without broken egg shells.
He noted which eggs were found more easily by crows. Because the crows used the white interior of a broken egg shell as a cue, they ate more the eggs that were near eggshells. Tinbergen concluded that eggshell removal behaviour is adaptive. It reduced predation and thus increases the offspring’s chance of survival.

Question 76

What are some examples of trade-offs?

Answer 76

Life history theory is based on the idea that evolution is constrained by trade-offs among some of the traits that contribute to fitness.
Each of these decisions will have pros and cons
Each of these decisions involve balancing costs and benefits, there will be trade-offs involved – if I go and do something I’ll get a benefit but there will also be cost involved.
For instance, trade-offs between going and foraging for energy and risking being killed when you’re going off foraging.
Physical costs of maintaining your body and repairing day to day wear, and reproduction – huge energetic costs, v. demanding. Should you spend energy maintenance and repairing your physical condition or put this energy into reproducing?
This is linked to the trade off of current and future reproduction. All energy and resources to breed now, or save some to reproduce again.
See a trade-off between the number of offspring you produce or the quality of offspring. Lots of low quality offspring or a few high-quality offspring [Demographic transition].
I’ve highlighted current vs future reproduction because this is an important concept.

Question 77

What is an example of territorial behaviour?

Answer 77

Defended by displays or attack (but carries a cost).

The defining characterises of territorial behaviour is defence against intrusion and resources use by others.
Territories are defended by displays advertising that the territory is occupied, and if that doesn’t work, they’ll attack intruders.
e.g. a bird sings on it’s perch to warn others this is it’s territory. If an intruder ignores the song and intrudes, then the bird will attack. Attacking others is costly, you may get hurt yourself. Singing may also advertise your presence to a predator.

Question 78

Why do animals bear the costs of territorial defence?

Answer 78

Well there are some energetic benefits, such as increased food intake due to exclusive use of resources, mating benefits – exclusive access to mates or access to refuges from predators. {exclusive club VIP picture}
E.g. hummingbirds benefit from exclusive use of a patch of flowers because they can efficiently harvest the nectar the flowers produce. The bird must actively defend the patch to keep exclusive use. In this case, the exclusive use outweighs the costs of defence.
e.g. In some lizards, males maintain enormous territories during the breeding season. A males territory will encompass many females territories, and is much larger than the male needs to supply itself with food. It’s because access for females is important and the territories are defended vigorously. In the nonbreeding season, male territory size decreases as does aggressive territorial behaviour. In the latter cases the benefits do not outweigh the costs. So the benefits and costs change depending on certain conditions.

Question 79

What are the benefits of care?

Answer 79

–offspring do better
but benefits likely to decrease as offspring grow (diminishing returns).

–mate has reduced costs
profitable if breeding again with same mate
mate will be in better condition.

Question 80

Costs of care:

Answer 80

reduced locomotor performance
pregnant snakes, lizards, bats
birds with eggs

–time and energy costs
lost opportunities(e.g. to get more matings)
energy spent; takes time to replace this

Question 81

What is the evolutionary advantage to EPCs?

Answer 81

• -Males, extra offspring, increased reproductive success
• -Females, mate with genetically superior males, or get additional help

E.g. Blue tits
(Cyanistes caeruleus)

Question 82

What is the conflict between parental care in dunnocks?

Answer 82

The conflict of interest facing parent dunnocks has a tension very common in all sorts of interactions – where the benefit depends on what others do, not just you, but you pay a cost in contributing to the team effort.

Question 83

What happened in trio dunnocks?

Answer 83

• -males share paternity (usually, α gets 60%) → lower gain from current brood
• -if β male’s paternity below a critical level, won’t help rear brood
• -above critical level, all three birds bring food to young.

Question 84

What are the conflicts in trio dunnocks?

Answer 84

–α male vs. β maleeach wants full paternity
–female vs. α malefemale wants to give β enough of paternity to enlist his help; α doesn’t want this
– α guards female
female tries to sneak away and copulate with β.

Question 85

• -Natural selection can cause behavioural evolution when variation exists in a trait, the variation affects ___ and the variation is ______.
• -Behavioural ecology is the study of _____ significance of behaviour.
• -An economic approach estimates the benefits and costs of behaviour.
• -________ success influences whether males and females mate _______ or with ______ partners.

Answer 85

• fitness
• heritable
• adaptive
• Reproductive
• monogamously
• multiple