Ocean wave observation utilizing motion records of seabirds

•A new ocean wave observation method using floating seabirds was developed.•GPS motion records of seabirds provide accurate information on the wave parameters.•Seabirds have the potential to complement gaps in ocean observation networks.•The effect of ocean waves on seabird behavior was also quantitatively evaluated.•The tolerance of wandering albatrosses to very high wave on 5–6 m was revealed.