Table 2.

Outstanding questions on the evolution of personality and cognition on islands.

The master data

Do island populations exhibit repeatable inter-individual differences in the way they behaviourally interact with their environment, and are these differences consistent across contexts?

Do populations (or communities) on islands exhibit the same range and relative frequencies of behavioural types as populations on the mainland, or on other islands?

Do animal populations on islands differ in cognitive skills from their counterparts on the mainland, or on other islands?

The mechanisms of change

What is the role of non-adaptive evolution (e.g. inbreeding, genetic drift, pleiotropy) in creating differences in cognition and personality between island and mainland populations?

What is the role of dispersal filtering in creating differences in cognition and personality between island and mainland populations? How long does this effect linger?

What is the role of phenotypic plasticity versus genetic adaptation in creating differences in cognition and personality between island and mainland populations?

The drivers of change

What is the effect of predator release on islands on personality traits? Are these effects general, or specific to a predatory context?

Does predator release on islands affect prey cognitive capacity? (How fast) do prey species lose their ability to recognize predators, to respond in adequate ways? Are these effects general, or specific to a predatory context?

How does reduced interspecific competition (and the possible resulting niche shift) on islands affect personality traits? Are these effects general, or specific to an interspecific context?

How do high population densities on islands affect personality?

How does low-resource availability or predictability affect personality traits, and cognitive capacity?

Covariation with other characteristics

Do changes in morphology (e.g. body size, shape and colour), physiology (e.g. brain size and digestive performance) or diet (type or breadth) observed in island populations concur with changes in personal or cognitive capacity? Are these changes adaptive or constrained?

Do changes in life history of the pace of life (fast to slow) on islands affect personality and cognition?

Generality and relevance

Are the magnitude and the direction of changes in personality and cognitive traits on islands consistent over taxonomic groups and island environments? If not, which factors are responsible?

How do personality and cognitive characteristics of island populations affect their vulnerability to alien species? How readily can island animals adjust personality and cognitive traits to cope with new challenges?