Data from: The effects of background risk on behavioural lateralization in a coral reef fish

Behavioural lateralization – the preferential use of one side of the body
or either of the bilateral organs or limbs – has been well documented in
many species, in a number of contexts. While the benefits reported are
numerous, existing latent variability in the degree of lateralization
within and across populations, species and taxa indicates that existing
costs may modulate its expression. Few studies have reported changes in
the degree of lateralization at the individual level, in response to
long-term changes in environmental conditions, but not in response to
short-term changes in environmental conditions. Predation is highly
variable both temporally and spatially and hence is a good candidate for
testing lateralization effects based on short-term changes in
environmental conditions. Here, we tested the hypothesis that the degree
of behavioural lateralization changes following short-term exposure to
different levels of risk. We tested whether wild-caught juvenile
damselfish exposed to a high or low background level of risk for 4 days
would subsequently differ in their turning bias, a trait that has been
linked to predator escape behaviour in fishes. We found that 4 days is
enough to induce a difference in the absolute lateralization scores of the
fish, with high-risk fish being more strongly lateralized than low-risk
fish. Practically, this difference stemmed from decreasing lateralization
scores for newly recruiting coral reef fishes that were kept in low-risk
environments, with the concurrent maintenance of higher lateralization
scores for fish maintained under high-risk conditions. Fish from the
high-risk background had higher survival than those from the low-risk
background upon release into mesocosms containing reef predators. Our
study highlights how early exposure to differential predation risk affects
the degree of behavioural lateralization. Given the profound effects of
lateralization on many aspects of an animal's life from its ability
to discriminate conspecifics to how it forages and interacts during
agonistic interactions, predation risk may be a key driver of animal
development.