A new subspecies of Cape Verde Storm Petrel Hydrobates jabejabe from São Tomé Island, Gulf of Guinea

Résumé fourni par la source

A new subspecies of Cape Verde Storm Petrel Hydrobates jabejabe, previously considered endemic to the Cape Verde Islands, is described from São Tomé Island, Gulf of Guinea. The formal description is based on evidence gathered from the literature, museums and fieldwork in and around São Tomé; namely, from four specimens collected in 1928, one bird trapped offshore in 1997, six birds captured at a palm oil factory in 2023, and digital images taken of several hundred birds at sea off São Tomé in 2023 and farther out in the Gulf of Guinea in 2011. São Tomé Storm Petrels were found to differ from H. jabejabe by bill shape (relatively long, slender, downcurved), plumage (extremely narrow white rump band in many individuals) and breeding ecology (presumed nesting at high elevation in tropical forest vs flat or sloped rocky areas near the sea). In a phylogenetic analysis using mtDNA control region, São Tomé Storm Petrels clustered within H. jabejabe, with the two not being reciprocally monophyletic. However, the unique haplotypes of the six individuals analysed from São Tomé, not found among 34 haplotypes from 58 individuals of hot- and cool-season breeders from Cape Verde, might indicate a lack of recent maternal gene flow. Integration of these multiple lines of evidence shows that, despite varying degrees of support, the São Tomé Storm Petrel is distinctive enough to be treated as a separate taxon. It is not sufficiently differentiated to warrant species-level status, so we treat it as a subspecies of H. jabejabe. Procellaria lugubris Bonaparte, 1845, a valid and available name whose holotype originates from the South Atlantic, could not be confirmed to refer to the São Tomé Storm Petrel.