In accord with AOS-NACC (Chesser et al. 2021), the nomenclature of Phalacrocorax (cormorants and shags), and the sequence of genera and species, are revised, following Kennedy and Spencer (2014) and Kennedy et al. (2019). Phalacrocorax is partitioned into six genera, which are listed in the sequence Poikilocarbo, Urile, Phalacrocorax, Gulosus, Nannopterum, and Leucocarbo. Change the scientific name of Chatham Islands Shag from Phalacrocorax onslowi to Leucocarbo onslowi.