Abstract
Diving petrels (genus Pelecanoides) are a group of small Southern Ocean seabirds whose taxonomy has remained problematic due to a lack of morphological diversity between species and limited availability of genetic data. Here we examine the phylogenetic relationships of the Pelecanoides diving petrels with analyses of the mitochondrial cytochrome b gene, focusing in particular, on the recently described and critically endangered Whenua Hou Diving Petrel (P. whenuahouensis). Pelecanoides whenuahouensis showed only minor sequence divergence from its sister species, the South Georgian Diving Petrel (P. georgicus), comparable to divergence levels observed between subspecies of the Common Diving Petrel (P. urinatrix). The paratype of P. whenuahouensis, which was collected from the now extinct population on the Auckland Islands, is genetically indistinguishable from P. georgicus raising the question of which species formerly bred on these subantarctic islands. Our genetic analyses provide insights into the phylogeography and evolutionary history of Pelecanoides and will help inform the conservation of the critically endangered Whenua Hou Diving Petrel.