mini mod.: animal behaviour

Question 1

Approaches to studying behaviour-pitfalls

Answer 1

*Ethology –form & function
*Neuroethology –neural control of behaviour
*Behavioural ecology –behavioural adaptations & selection pressures
*Sociobiology –social behaviour
*Behavioural genetics –control of behaviour by multiple genes & modifiers of gene expression
Phsychology-perception, mental representation, learning, etc.
Anthropology -humans + human origins

PITFALLS:
Anthropomorphism - naive extrapolation from humans to animals(smiling-animals smile out of fear/aggression)
Naive soiciobiology- sexism, racism, militant atheism

Question 2

 definitions:

communication
signals
cues
eavesdropping+communication networks
animal senses

Answer 2

Communication: Passing of information from a sender to a receiver.

Signals: A feature of an animal that has evolved specifically to alter the behaviour of receivers.

Cues: Any feature that can be usedby an animal as a guide to future action.

Eavesdropping & communication networks- can be exploited by predators eg. Owl

Animal senses: Methods by which animals perceive their environment - Perception of the external world depends on sensory systems

Question 3

how signals evolve

Answer 3

Cues revealing autonomic stimulation
Respiration
Urination/defecation-chemical marking of territories
Thermoregulation-raising hair/feathers
Pupil dilation-friendliness/arousal
Yawning-signal of aggression to primates(humans don’t fight with teeth so become physiological role)

Signals evolve to maximise transmission and minimise eavesdropping
Eg. Conspicuousness to a predator

Guppies exposed to different predators
have different colour patterns
Predators drive selection for use of “private wavelengths”

Question 4

ritualised signals V cues

Answer 4

conspicuous- increase detect ability
Redundancy
Stereotypy
Alerting components

Ritualisation of cues revealing changes in behaviour:
Intention movements
Self protective movements
“Displacement” behaviours

Question 5

signalling danger

Answer 5

Communication with other prey
Alert
Flee
Assemble
Attack

Communication with predator
Startle displays
Aposematism = conspicuous warning of unprofitability
Pursuit deterrence e.g. mobbing

Question 6

vervet monkey

Answer 6

An eg. Of coding
Learned calls for specific circumstances :
‘Leopard’ -head for trees
‘Snake’ -stand + search
‘Raptor’ -look at sky

Question 7

sexual selection

Answer 7

Sexual selection-natural selection for traits that increase reproductive success

Question 8

sexual V natural selection

Answer 8

natural:
Variation between individuals
Variation effects survival
Variation is inherited

sexual:
Variation between individuals
Variation effects reproductive success
Variation is inherited

Question 9

Anisogamy-unequal gametes

Answer 9

Eggs are large & expensive,
sperm are small & cheap!
*Males produce huge numbers of tiny sperm
*Females produce a relatively small number of eggs
*Females (usually) invest more in growing & caring for each offspring
Ardent males compete for choosy females!

Question 10

Intra-sexual competition

Answer 10

MALE - MALE COMPETITION
Ardent males compete for access to females
-fighting-dangerous
-ritualised contest-roaring
-guard of females-forced mating(rape eg. Ducks)
-sperm competition-Competition for inseminations between the sperm of rival males

Question 11

Inter-sexual selection

Answer 11

FEMALE CHOICE
Selection favours females who choose the best possible males to mate with
Benefits of choosing good quality mates:
Good resources & parenting ability
Good genes (high quality sexy parents have high quality sexy offspring)

Question 12

Methods to impress females

Answer 12

Defeat opposition
Defend high quality territory
Provide ‘nuptial gifts’ =courtship feeding
Advertise genetic benefits of a good choice
1. Have attractive traits=runaway sexual selection
2. strategic “handicap”Conley high quality males can afford to possess(hard to escape predators-peacocks tail)

Question 13

Sexual conflict

Answer 13

Conflict of interest between male and female
Eg. Sexual cannibalism
Eg. Infanticide

-can be over parental care
-some situations, females compete for males

Question 14

Mating systems

Answer 14

monogamy - eg. European robin
polyagomy/polygyny - eg. marsh harrier
polyandry - eg. phalarope
polygynandry - eg. kentish plover
promiscuity - eg. aquatic warbler

Question 15

Eg. Of cooperation- parental care, helping siblings

Answer 15

parental care:
Offspring have copies of parents genes, so helping offspring (by feeding them) is an effective way of maximising genetic contribution to future generations
Each parents contributes 50% of its genes to each offspring

helping siblings:
Siblings have coefficient 0.5 so individuals could maximise their genetic contribution to next generation by:
Helping to rear their full siblings
Rearing their own offspring

Question 16

Coefficient of relatedness

Answer 16

= genetic similarity of 2 individuals relative to the population as a whole
= probability that 2 individuals share a gene that is identical by descent(from same ancestor)
= probability of sharing a rare allele

Question 17

”Genes eye view” of selection

Answer 17

A gene can maximise its transmission to the next generation by:
Direct fitness-maximising the reproductive success of the individual it is in
Indirect fitness-maximise the reproductive success other individuals who share copies of that gene

inclusive fitness = direct + indirect fitness

Question 18

Optimising long term fitness

Answer 18

Animals should maximise their lifetime inclusive fitness
Kin selections- the process by which traits are favoured due to their effects on the fitness of relatives

Question 19

Hamilton rule

Answer 19

Identifies the conditions under which altruism will spread due to kin selection
Altruism will be favoured if:
r x B - C > 0
r = coefficient of relatedness between actor and recipient
B = benefit to recipient
C = cost to actor

Question 20

Extreme altruism

Answer 20

Eg. Extreme altruism: suicide and sterility in the social insects
Bee stings are fatal to the worker bee = suicide
Workers rarely reproduce themselves but instead help their mother(queen) to produce offspring= sterility

Male develop from unfertilised eggs and so are haploid: all genes come from mother
Females Develop from fertilised eggs, so are diploid: half genes from mother, half from father

Question 21

Eg. Naked mole rat (sabre toothed sausage)

Answer 21

Reproductive divisions of labour:
One reproductive female “QUEEN”
1-3 reproductive males
Reproductive suppression of “workers”
LOTS of close relations(20-300 individuals)
High coefficient of relatedness
Cooperative brood care
Overlap of generations
Cooperative foraging(sharing highly patchy foods = tubers)

Question 22

Coop courtship in wild turkeys

Answer 22

Male turkeys form coalitions to court and defend females
One dominant male(gets all the matings)
One subordinate male(gets no matings)

Measure relatedness using micro satellite markers r=~0.5 ie. Brother-brother or father-son coalitions

Estimate benefits of cooperation by comparing reproductive success of single or dominant males
Estimate cost by comparing reproductive success of single or subordinate males

Question 23

Reasons to cooperate

Answer 23

1. Kin selection- indirect benefits to the cooperator, via benefits to close relations
2. By product benefits
3. Reciprocity
4. Enforcement
5. Deception

Question 24

2. By product benefits

Answer 24

Cooperation is the best option from a selfish perspective, but happens to help others too
Eg. Cooperative hunting increases net food intake

Question 25

3. reciprocity

Answer 25

Net benefit in the longer term
Favoured by repeated interactions between individuals
Eg. Mutual grooming, eg. Reciprocal feeding of blood meals in vampire bats

Question 26

4. enforcement

Answer 26

Cost of “defecting” are extremely high eg. Punishment in human and primate societies

Question 27

5. deception

Answer 27

Animals my cooperate “by mistake”
Manipulation of receivers by signallers
Eg. Large blue butterfly caterpillars deceiving ants
Eg. Cuckoos deceiving reed warblers

Question 28

Spite – in animals

Answer 28

Spite - incurring cost to your own reproduction by harming others
Spite will be favoured if:
r x B - C >0. B(benefit to recipient)= negative
This can occur if r is negative (ie. If relatedness between actor and recipient is less than the population average)

Spite in animals
Most potential eg. Can be explained by longer-term direct benefits eg. Male-male fights
Real eg. Parasitoid wasps

Question 29

 Prisoners’ dilemma