The Hawaiian petrel is now limited to a very small breeding range and its population is suspected to have declined severely over the past few centuries (2). The historical decline of this species is likely to be due to hunting by humans, which eliminated the Hawaiian petrel from many of the Hawaiian islands (2) (6). Like other seabirds, the Hawaiian petrel is also suffering from the introduction of non-native species. Over the years, dogs, pigs, rats, cats and the small Indian mongoose (Herpestes javanicus) have been introduced to the islands. Predation by these animals affects both adult petrels and their eggs and chicks (2) (6) (7).
Another kind of threat is posed to this species by feral goats and pigs, which may trample nesting burrows (6). Urbanisation has also meant a severe decline in nesting sites for the Hawaiian petrel (2).
On the island of Lana`i, the habitat is also being degraded by the spread of the invasive tree strawberry guava (Psidium cattleianum), threatening the long-term survival of the island’s Hawaiian petrel colony (2).
Flying mostly at night, the Hawaiian petrel is often disoriented by artificial lighting, and fledglings may become grounded after flying into lights. Once grounded, the young birds are vulnerable to predators and cars, or can die from starvation (2) (6). Collisions with artificial objects, such as power lines and buildings, are also cause for concern (6).
The Hawaiian petrel may also be negatively affected by environmental changes in its oceanic feeding grounds, which can alter prey availability (2).