We investigated cryptic species across the range of band-rumped storm-petrels</p><p>(Hydrobates spp.): highly pelagic, nocturnal seabirds that breed on tropical and sub-tropical islands in the Atlantic and Pacific Oceans. In many breeding colonies, band-rumped storm-petrels have sympatric but temporally isolated (allochronic) populations we sampled all breeding locations and allochronic populations.