Juvenile exposure to acoustic sexual signals from conspecifics alters growth trajectory and an adult personality trait

Animal personalities have become an established concept in animal behaviour. Despite this, the potential influence of early life experiences on adult personality is often overlooked. Juvenile exposure to environmental cues such as conspecific signalling or predator cues may provide relevant information regarding the make-up of the forthcoming environment. Individuals might be able to use these cues to adjust developmental trajectory and adult personality to prevent a personality–environment mismatch. Using the field cricket Gryllus integer, we show that individuals reared in the presence of conspecific acoustic sexual signals alter both growth rate and an adult personality trait. Males reared in the presence of acoustic sexual signals were less aggressive and less likely to become dominant relative to those reared in the absence of acoustic signals. Additionally, acoustic treatment interacted with juvenile body mass: large juveniles reared in the presence of acoustic signals were larger than small juveniles reared in the presence of acoustic signals and larger than all juveniles reared in silence. We discuss the potential adaptive significance of the observed developmental and personality differences.