Short-term exposure to an endocrine disruptor affects behavioural consistency in male threespine stickleback

► I examined the effect of EE2 on reproductive behaviour and consistency in stickleback. ► Short-term exposure affected reproductive behaviour and consistency across trials. ► EE2 reduced behavioural consistency of both courtship and aggression. ► Threespine stickleback males may vary in their sensitivity to EE2.