Researchers have analyzed tracking data for 5,775 birds across 39 species of albatrosses and large petrels -- threatened seabirds whose ranges span many countries and the high seas -- to estimate how responsibility for their protection should be distributed among nations and international organizations. The authors note that albatrosses and large petrels from all breeding countries spend much of their time on the high seas, indicating that effectively managing these waters is of global interest. These estimates are critical to inform ongoing United Nations discussions to design a global treaty for conserving biodiversity in the high seas, beyond national jurisdictions, the authors write. Many species of albatrosses and large petrels are threatened due to overfishing of their food sources, mortality from entanglement in fishing equipment, pollution, and climate-related changes to their habitats. Conservation efforts by one country may be nullified if another country in a species' range does not act, or if high seas regions, such as those governed by regional fisheries management organizations (RFMOs), are unprotected. Thus, effective conservation requires international agreements. To determine the relative responsibility countries and RFMOs share for protecting these species, the authors collected, regularized, and analyzed tracking data from a variety of sources to determine where the populations breed, which countries or marine regions they visit, and the networks of the species' annual migrations between these places. Their findings support existing agreements, such as the Japan-Australia Migratory Bird Agreement, but also reveal important gaps. For example, neither Japan nor Australia has agreements with Russia, where many of their birds spend time.