Expected effects of the predator treatments under the three hypotheses mentioned in the introduction and the observed differences (-: predator treatments < control treatment, 0: predator treatments = control treatment, +: predator treatments > control treatment).

aIf helpers showed any predator defence in the predator treatments.
bHelp or submission as ratio of breeder punishment.
cNo effect in the focal observations, but effect in digging experiment.
dHelpers joined defence against the introduced predator, but also clear evidence for risk avoidance due to aggression declining with N. pulcher body size.
eNo clear predictions here, but there was a correlation between helper submissiveness and breeder punishment (supporting risk avoidance), which was not matched by an increase in the submission ratio in the predator treatments compared to the control treatment (contra risk avoidance).