Reading 6.1 Green et al Flashcards
1
Q
The study hypothesis
A
- The hypothesis was that variation in the contribution of helpers to cooperative brood care among species of cooperatively breeding birds is predicted by inclusive fitness theory
2
Q
What is the state of current literature?
A
- No evidence for kin discrimination in the amount of help provided by helpers. Thus, we currently have no explanation for the considerable inter-specific variation in the amount of effort that helpers contribute towards cooperative brood care.
- Current debate that kin selection theory is weak (Nowak, Martin A et al)
3
Q
What type of analysis did the study use?
A
Comparative analysis
4
Q
How many species and bird families was the study based on?
A
36 species forming, 23 families
5
Q
What was used as the benchmark for helper effort?
A
Parental effort
6
Q
How was the analysis done?
A
Phylogenetic generalized least squares analysis
7
Q
Kinship is not the only predictor of helper effort, what three other measures had to be accounted for?
A
- Reproductive constraint
- Parental investment decisions in regard to carers at the nest
- The care of helpers could vary consistently with sex
8
Q
What did the results show?
A
-Amount of care increasing with kinship
- Helper effort was not predicted by the percentage of nests with helpers or group size
- helper effort was found to decrease significantly with the proportion of helpers that were male
- more female-biased helper sex ratios were associated with higher ecological constraints
9
Q
Results in regard to the hypothesis
A
Support for Hamilton’s theory as amount of care increased with kinship
10
Q
What the study adds to animal behaviour as a whole?
A
- Reaffirms the central role of relatedness in the expression of cooperative behaviour in the light of recent debate
- Demonstrate the continuing utility of inclusive fitness theory in our understanding of social evolution.
