Socioecology

Question 1

When do primates form polyspecific associations?

Answer 1

When there is mutual benefit to both species

Question 2

What benefits are there from polyspecific association? Give 2

Answer 2

1. Predator protection

2. Increased foraging success

Question 3

Give an example of polyspecific association.

Answer 3

Saddleback tamarins and emperor tamarins

Question 4

How can saddleback and emperor tamarins forage together without competitive exclusion occurring?

Answer 4

They have different foraging and locomotor styles, i.e. different ecological niches

Question 5

Which parts of the canopy do a) saddleback and b)emperor tamarins forage in?

Answer 5

a) Understory

b) Canopy

Question 6

Often insects lost by emperor tamarins are caught by the saddleback tamarins below. True or false?

Answer 6

True

Question 7

How is the relationships between saddlebacks and emperors mutualistic?

Answer 7

Saddlebacks watch for predators from below, and emperors for predators from above.

Question 8

Give another common polyspecific association seen in the wild.

Answer 8

One between (brown) capuchins squirrel monkeys

Question 9

Why do capuchins and squirrel monkeys associate?

Answer 9

For increased foraging success and predator evasion.

Question 10

How do capuchins and squirrel monkeys avoid predators?

Answer 10

There are more eyes and ears watching, both species respond to the other’s alarm calls and capuchins will sometimes mob predators.

Question 11

Is affiliative behaviour ever observed between capuchins and squirrel monkeys?

Answer 11

No, in fact the caps are often mean to the squirrels

Question 12

If there are scarce resources what does selection favour?

Answer 12

Behavioural and morphological traits that fare better in competition

Question 13

Why does resource competition have more impact on females than males?

Answer 13

Because females have higher investment in producing offspring

Question 14

When does scramble competition occur?

Answer 14

When a resource CANNOT be monopolised

Question 15

Why can a resource not be monopolised?

Answer 15

Because it is dispersed over a large area

Question 16

In scramble competition, does every group member have equal access to the resource?

Answer 16

Yes

Question 17

There is a threshold to scramble competition. Why?

Answer 17

After a certain number of individuals access to the resource decreases

Question 18

When does contest competition occur?

Answer 18

When a resource CAN be monopolised.

Question 19

Why can a resource be monopolised?

Answer 19

It occurs in discrete patches so cannot be shared.

Question 20

Why does contest competition occur for females?

Answer 20

Because the fertilisation of an egg cannot be shared.

Question 21

In contest competition, who benefits most from resources?

Answer 21

Dominants, as they can restrict the access of subordinates to resources.

Question 22

Whose reproductive success is favoured in contest competition?

Answer 22

Dominants

Question 23

In scramble competition resources are high quality and concentrated in one place. True or false?

Answer 23

False, they are low quality and highly dispersed

Question 24

In species with scramble competition, is there an advantage to having high rank?

Answer 24

No as food cannot be monopolised

Question 25

Species with scramble competition have what kind of societies?

Answer 25

Egalitarian

Question 26

Scramble competition is often for nutrient-poor food. Species with scramble competition have longer what?

Answer 26

Feeding times and day ranges

Question 27

Although there is a threshold at which group size becomes disadvantageous in species with scramble competition, what is the advantage to having a larger group?

Answer 27

Predator protection (forms a trade-off with decline in energy)

Question 28

How can you describe the societies of species with contest competition?

Answer 28

Despotic, dictatorial, unequal

Question 29

Contest competition is for what kind of food?

Answer 29

Nutrient-rich

Question 30

In species with contest competition lower ranking members have the same food intake as higher ranking. True or false?

Answer 30

False, their food intake is lower

Question 31

What behavioural trait is selected for in species with contest competition?

Answer 31

Feed until sated to ensure greater share of food, i.e. shove everything into their mouths until they can't carry any more

Question 32

In species with contest competition foraging-related aggression is common. How do females cope with this?

Answer 32

Feed away from others

Question 33

Kin cooperation is favoured in species with scramble competition. True or false?

Answer 33

False, it is favoured in species with contest competition. Relatives become allies in resource control.

Question 34

What is the result of foraging aggression in species with contest competition?

Answer 34

Displacement.

Question 35

In between-group contest, which groups gain access to resources?

Answer 35

Larger groups

Question 36

Do primate societies always follow the social structure predicted by 'food = female distribution = male distribution'?

Answer 36

No.

Question 37

What is menarchy?

Answer 37

A female's first menstrual bleed

Question 38

In Western European humans, the age of menarchy has reduced from ~14 to 11. These individuals are sexually mature but they are not...?

Answer 38

Socially mature

Question 39

Why is it thought a lowering in the age of menarchy has occurred in western civilisations?

Answer 39

These countries are richer and have more abundant resources

Question 40

Female reproductive success is inexorably linked to what?

Answer 40

Foraging success

Question 41

If a female has access to more resources she can do what?

Answer 41

Reproduce at an early age

Question 42

Why is reproduction so expensive to females?

Answer 42

They need energy to feed themselves and the foetus during pregnancy, and still maintain enough body fat required to nurse when the infant is born

Question 43

How much higher is the female's energy requirement during lactation?

Answer 43

2-5 times higher.

Question 44

What constitutes a 'high quality' diet?

Answer 44

Readily digestible, energy-rich food

Question 45

What is a 'growth diet'?

Answer 45

Diets that are not available all the time but can be used to fuel reproduction

Question 46

What is a 'fallback/subsistence food'?

Answer 46

Foods that are consumed when the preferred food is not available

Question 47

What adaptations do folivorous primates have for eating leaves? List 3.

Answer 47

1. Shearing molars 2. Strong chewing muscles 3. Elongated digestive tract to increase processing time/area

Question 48

Some folivores have developed extra strong teeth and muscles, why?

Answer 48

To get past plant defences like shells and husks

Question 49

As well as physical, plants produce chemical defences. Which chemical groups to these belong to?

Answer 49

Tannins and alkaloids

Question 50

Are these always toxic?

Answer 50

No, they can be medicinal in the right dose

Question 51

Young leaves are high in toxic compounds and are avoided. True or false?

Answer 51

False, mature leaves are toxic

Question 52

Why do red colobus monkeys eat charcoal?

Answer 52

To neutralise plant toxins

Question 53

Females and males of the same species often eat different foods. True or false?

Answer 53

True

Question 54

Why might females and males of the same species often eat different foods? Give 2 reasons.

Answer 54

1. To avoid inter-sexual competition 2. Because they have different energy requirements (the latter is preferred, no one is really sure)

Question 55

Why do species exhibit behavioural adaptations instead of morphological? For example, why do red colobus monkeys eat charcoal to neutralise plant toxins, why don't they just eat noon-toxic plants? Give 2 reasons.

Answer 55

1. Because it is quicker to develop a new behavioural phenotype than a new behavioural/physiological. 2. Behavioural repertoires are flexible whereas morpho/physiological constraints are not. Primates are incredibly adaptable because of their behavioural flexibility.

Question 56

It can be assumed that nutritional uptake reflects the food availability and security of the environment. Therefore species living in similar environments always behave in the same way. True or false?

Answer 56

False, there are always exceptions, can also depend on factors like competition and predation etc.