Genetic correlation between behavioural traits in relation to death-feigning behaviour

Individuals frequently behave in a consistent manner across time or in different situations. We examined the repeatability of duration of death-feigning anti-predator behaviour when attacked, and then carried out artificial selection for duration to calculate its heritability and examine correlated responses to selection in activity levels, in the confused flour beetle, Tribolium confusum. Three replicates of two strains were established by artificial selection for more than 17 generations: S strains exhibited shorter duration and lower frequency of death feigning while L strains exhibited longer duration and higher frequency of death feigning. Duration of death feigning clearly responded to selection, and significant value of realized heritability was detected in all replicates of the two strains. Examination of locomotor activity levels over a constant period showed that S strains had higher locomotor activity levels than L strains. No significant differences between the sexes were observed. Our study thus demonstrates heritability of death feigning and the existence of a negative genetic correlation between intensity of death feigning and activity level.