Aggression
To quantify aggression in butterflyfishes we used 5-minute focal follows (n=1177) and scored each encounter (a non-focal fish within 1m of the focal fish), as passive (no response) or aggressive (signalling by flaring fins and or through aggressive posturing, or chasing by one or both individuals). Focal individuals of any butterflyfish (Chaetodontid) species were selected haphazardly based on order of encounter. There was not sufficient replication at the species level across the sampled years, so aggression scores were pooled in each year.