Animal Behav. Chapter 1: Principles of Animal Behaviour

What are the 4 questions asked to predict animal behaviour and why do we ask them?

Mechanism, Developmental, Evolutionary, survival value

• we ask them to understand the proximate and ultimate causes of a behaviour

Mechanism

• what physiological mechanisms happen as a consequence of behaviour?

• what stimuli elicits the behaviour

Developmental

How does behaviour change over ones life?

• how do developmental processes as a fetus change how an individual behaves 

Survival Value 

• does the behaviour offer survival value and increases fitness of the individual 

• ex. courting behaviours 

Evolutionary change

how does behaviour vary due to evolutionary history

• evolved and adaptive behaviours

Singing Crickets and Parasites 

• an example of natural selection and darwinian theory that behaviours evolve when they increase fitness 

• male crickets sing as a courting behaviour however the singing also attracts flies that kill the cricket 

• flatwing crickets evolved in order to not attract flies but also be able to reproduce by being near singing crickets 

Xenophobia in molerats

Method: comparing mole rats from arid (low resource environments) and mesic (high resource environments)

• aggression was recorded to same and opposite sex strangers

Findings: mole rats from arid environments were more aggressive toward strangers of the same sex

• aggression decreased with opposite sex but was still more aggressive than mesic mole rats

• this shows this is an adaptive behaviour because they adapt to not trust strangers when there are limited resources to increase their survival

Grasshopper Individual Learning Experiment

• grasshoppers are able to learn what foods are associated with a balanced or bad diet based on their colour and scent

• one group of grasshoppers were put in a randomized environment and another put in a controlled environment

• controlled environment grasshoppers were able to learn an association between colour and scent and a balanced diet and the random grasshoppers were not able to learn

Cultural Transmission and social learning in Rats 

• rats do not eat novel foods 

• experiment tested their ability to eat novel foods 

• demonstrated rats learned to eat a novel food such as chocolate or cinnamon and then interacted with the observers so they could smell them 

• rats that interacted with another rat who ate cocoa preferred it

• rats that interacted with another rat who ate cinnamon preferred it

  • over a generation, food preference will get passed down because they learn which novel food is safe through those around them.

Conceptual approach 

integrating existing ideas into theories in new ways 

• ex. kin selection theory: behaviours that increase fitness are favoured by potential mates 

Empirical Approach

data collection through observation or experiments

• data is used to male a hypothesis about animal behaviour

Theoretical approach

• creating models to predict behaviour

  • optimal foraging theory: animals choose to maximize energy intake and decrease time foraging

Fruit Flies and Artificial Selection

• flash flies with a red light to activate their neurons and make them fight 

• aggression increased with the flashes 

• CAUSED A DRAMATIC INCREASE IN THE NEXT GENRATION 

Fruit flies and artificial selection graph

• neutral label = no induced aggression

  • low fighting frequencies in both generations

• aggrl label = induced aggression

  • high fighting frequencies that significantly increased in the next generation

• this shows successful artificial breeding

List four causes to improvements observed in placebo treatments?

1. spontaneous improvement

2. statistical regression of the mean

3. co-intervention

4. bias

What are the two mechanisms that can change behaviour over time?

evolution and learning

Explain the evolution of beak size in finches.

Individuals with large beaks are more efficient at cracking open large, tough seeds. Those with small beaks are better with small seeds.

There was a drought in 1977-78 that killed 80% of finches because it favoured those with large beaks (who could crack open the large

seeds)

What are the three prerequisites of natural selection?

Variation in the trait, fitness consequences of the trait, a mode of inheritance