Practical 2 - crickets

Question 1

What is habituation?

Answer 1

Innate responses to a stimulus decrease after repeated exposure to the stimulus

Question 2

Why is habituation important?

Answer 2

Ensures behavioural responses are accurate and not caused by fear or stress as well as it being ethical

Question 3

Cricket natural behaviours to look out for

Answer 3

Walking, running, antenna movement / fencing, stridulation (singing), harsh chattering, chasing, mandible fighting

Question 4

What is an ethogram?

Answer 4

A catalogue of behaviors defined

Question 5

Why is an inter-observer reliability test important?

Answer 5

Represents the extent to which data is collected accurately with each observer describing behaviours the same way

Question 6

What to do if the chi-squared of your inter-observer reliability tests is < 0.8?

Answer 6

Look back over ethogram and redefine behaviours / make definitions more clear

Question 7

Issues with taking cricket body mass?

Answer 7

Movement on scales, missing appendages, don’t know when last fed

Question 8

Why do we measure the pronotum?

Answer 8

Good proxy for size

Question 9

How did we assess aggression?

Answer 9

Observe frequency and level of aggression of fights in a period of time

Question 10

What did we use to tell crickets apart?

Answer 10

Marked each with a different coloured spot of non-toxic paint

Question 11

How to tell the loser and winner apart?

Answer 11

Loser walks away from encounter, winner chases loser, body jerking and singing

Question 12

Important hypotheses

Answer 12

Greater difference in pronotum size = increased aggression, larger males start more fights to assert dominance, more likely to win if the crickets starts the fight

Question 13

How were the crickets prepped?

Answer 13

Weigh body mass on scale in petri dish, measure pronotum width using digital callipers, left for 5 min to habituate

Question 14

Tinbergen’s 4 questions about animal behaviour

Answer 14

Ultimate (why), proximate (how)

Question 15

Tinbergen’s ultimate questions

Answer 15

Function (what is the behaviour for?) and evolution (where has the behaviour come from?)

Question 16

Tinbergen’s proximate questions

Answer 16

Development (how does the behaviour develop?) and mechanism (how is the behaviour achieved?

Question 17

What is a display?

Answer 17

Any behaviour pattern especially adapted (i.e. modified through evolution) in physical form or frequency to function as a social signal in communication

Question 18

4 kinds of signals which animals use to communicate?

Answer 18

Auditory, olfactory / chemical, visual, tactile

Question 19

Response rate to signals

Answer 19

Immediate (e.g. alarm calls), gradual (e.g. courtship) or both

Question 20

Discrete signals

Answer 20

All or nothing (e.g. fixed action patterns)

Question 21

Graded signals

Answer 21

Varying intensity and / or frequency

Question 22

What is a fixed action pattern?

Answer 22

A discrete behavioural unit that is sterotyped, innate and is performed in an all-or-nothing fashion when the animal is triggered by a certain stimulus

Question 23

What happens when a stimulus is detected?

Answer 23

It triggers an Innate Releasing Mechanism within the nervous system that generates the FAP motor output

Question 24

Statistical tests used?

Answer 24

Correlation (Spearmans Rank) and T-test / Mann-Whitney U