lab 9?

Question 1

Behavioural ecology

Answer 1

studies the relationships between organisms and their environment that involve interactions with behavior.

Behaviours have been shown to have a genetic basis and can be a mechanism for increasing the individual’s inclusive fitness (the survival and reproduction of the individual plus all individuals who s hare genes).

Question 2

phenotypic plasticity

Answer 2

Phenotypic plasticity refers to the ability of organisms with the same genotype to produce different phenotypes (physical appearances/ physiologies) in response to different environmental conditions

Variation in behaviours can arise through various mechanisms including phenotypic plasticity.

A phenotypic response to the environment occurs during development and growth, and results in increased the survival of the individual, and is not reversible

Question 3

the Madagascar hissing cockroach (MHC) (Gromphadorhina portentosa)

Answer 3

that is endemic to the island of Madagascar and has been a widely studied social insect.

MHC belong to the same class (Insecta) and have a basic body plan with a head, thorax and abdomen.

They are dioecious: that is, they exist as distinct male and female individuals.

1987). In the wild they are found living in large groups under rotting logs and debris, and their social structure is a male dominance hierarchy.

The thorax contains modified spiracles that the cockroach forcefully expels air through, creating a “hissing” noise.

have been observed to exhibit agonistic behaviour.

Question 4

agonistic behaviour,

Answer 4

which defines aggressive interactions between members of the same, social species.

A high social status, or dominance, can offer the benefit of greater access to food, mates and shelter for the “winner” of agonistic interactions.

Factors that affect winning an agonistic encounter range from the physical features of the individual to the past events that have occurred.

Question 5

We will be examining

Answer 5

the physical effects on the structure of dominance by placing a pair of cockroaches in the same arena (done twice for each research group) and observing their actions toward each other.

expected to use excerpts provided and Table I.1 to formulate a hypothesis for determining the outcome of your “fights” based on a physical characteristic of the cockroaches.

Question 6

Methods

Answer 6

Each research group will run two simultaneous trials with two separate pairs of cockroaches.

Using the information provided from your class hypothesis, choose a suitable pair for each interaction that will allow you to test your hypothesis and record the appropriate measurements.

_{(*hint: remember that consistency is important in all variables except the one being tested)}

may need to mark your cockroaches.

Obtain two arenas and place the divider so that it is divided into two equal halves.

determine the size of the cockroach.

Place one marked cockroach on either side of the divider in each arena, using either your clean hands or gently prod the cockroach from his individual container to the arena.

Leave the cockroaches separated by the divider for 5 minutes to allow them to acclimate to their new conditions.

After the 5 minute acclimation period, remove the divider and start the timer.

In addition to recording observed behaviour when you see a change occur, you will be scoring aggressive behaviours and watching for a ‘crouch’ or a ‘retreat’ to signify submissi on.
_{When this occurs, you can note which cockroach has ‘won’ the bout or is considered dominant by points.}

Observe your cockroach for up to 25 minutes; you may stop if an obvious winner is evident.

note
_{can sometimes take more than 5 minutes for the cockroaches to approach each other, and may also fight and take breaks before a winner is determined.}

When finished, you may return both individuals to their separate containers and clean out your arenas,

Question 7

Table I.1. Behaviour involved in agonistic interactions of male Gromphadorhina portentosa

(from Clark and Moore 1994; scoring from McDermott et al. 2014)

Answer 7

Behavior: Abdomen Flick
Description: Thrust abdomen in an upward direction contacting opponent
Function: Aggression
Score: 1

Behavior: Abdomen Push
Description: Push another individual with the abdomen placed under the opponent
Function: Aggression
Score: 1

Behavior: Abdomen Thrash
Description: Horizontal shaking and beating of the abdomen on the substrate
Function: Undescribed
Score: 0

Behavior: Abdominal Extension
Description: Extend and telescope the abdomen in an upward direction
Function: Undescribed
Score: 0

Behavior: Agonistic Hiss
Description: Production of a distinct audible sound in the presence of other m ales
Function: Undescribed
Score: 0

Behavior: Antenation
Description: Contact with the antennae
Function: Olfaction?
Score: 0

Behavior: Approach
Description: Directed movement toward another individual
Function: Undescribed
Score: 0

Behavior: Butt
Description: Lower pronotum to expose horns and charge forward; contact made with horns
Function: Aggression
Score: 1

Behavior: Crouch
Description: Lower body against substrate and remain motionless
Function: Submission
Score: 0

Behavior: Lunge
Description: Forward thrust of the body toward an opponent
Function: Aggression
Score: 1

Behavior: Retreat
Description: Moving away from an individual and/ or an interaction
Function: Submission
Score: 0

Behavior: Sideways -Lean
Description: Drawing one side of the body toward the substrate
Function: Undescribed
Score: 0

Behavior: Sit On
Description: Sitting on or crawling over another individual
Function: Undescribed
Score: 0

Behavior: Stilt
Description: Raising the front of the body off of the substrate
Function: Undescribed
Score: 0