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.