Non-lethal effect has become an important part of predation risk,which shows increasing influence over density-mediated interaction.With complex anti-prey strategy and behavior,birds provide good examples for non-lethal effects study.This review summarized progress in non-lethal effects studies on birds.Previous work showed that non-lethal effects tolerance could affect individual fitness and population regulation and dynamics.Moreover,birds' evaluation on non-lethal stimulation is influenced by many factors,eg.individual condition,perching height and group size.Knowledge and understanding of non-lethal effect on birds may play a key role in predation risk trade-off theory,population modelling,and coexistence of human being and birds.