Hydrobatinae is one of two subfamilies of storm-petrels. The distribution of the subfamily is predominantly in the northern hemisphere. The subfamily contains two (sometimes three) genera in which there are 14 species. They were the first group of storm-petrels to break off from the ancestral petrel stock, and for this reason some authors have suggested that they should constitute a separate family from the Oceanitinae storm-petrels. Subfamily Hydrobatinae European Storm-petrel Hydrobates pela… (More on Hydrobatinae)