Newell’s shearwater (Puffinus newelli)
|Also known as:||‘A’o|
|Synonyms:||Puffinus auricularis newelli|
|Size||Length: 33 cm (2)|
Male weight: 389 – 425 g (2)
Female weight: 343 – 422 g (2)
Classified as Endangered (EN) on the IUCN Red List (1).
Newell’s shearwater is called the ‘A’o in Hawaii, a name given for the moan-like call this seabird emits when in its burrow, which Hawaiians once believed sounded like an omen of death (3). This attractive bird and magnificent flier is undeserving of such an association, and is now so rare, one would be lucky to hear its nesting cry (3). It has dark, sooty brown plumage on its upperparts and white underparts, with the white extending up the throat and to the sides of the rump (2) (4). It has a dark bill (4), with a hooked bill and sharp blades, enabling it to deal with slippery prey with ease (5).
Newell’s shearwater breeds only on the Hawaiian Islands: principally Kaua‘i, but also Hawai‘i and Moloka‘i, and possibly also on O‘ahu, Maui, and Lāna‘i (6). At other times of the year, this oceanic bird wanders far over the central Pacific Ocean (2).
Newell’s shearwaters are oceanic birds, found north of the equator over waters deeper than 2,000 metres (2). It nests on steep, mountain slopes, typically between 160 and 1,200 metres above sea level and up to 14 kilometres from the coast (2).
Like other shearwaters, this species flies fast and often low over the ocean (2). Here it forages, often in association with wedge-tailed shearwaters, sooty terns and boobies, for small fish and squid (2). It dives into the water to pursue and capture its prey, often exploiting the actions of tuna and cetaceans, as they drive shoals of small fish to the surface (2).
In the last week of April, adult Newell’s shearwaters arrive at their island nesting grounds. During the first two weeks of June, they lay a precious, single egg into a burrow which has been dug under matted ferns or tussock grass (2), often at the base of a tree (4). The egg is thought to be incubated for around 51 days by both parents (2), who continue their parental care when the egg hatches, spending the daylight hours foraging in the ocean surrounding the island, travelling up to 1,200 kilometres from the colony, and returning at night to feed the chick (2) (4). By November, the young will have fledged and the parents provide no further care, leaving the young to start life on the open oceans (4). During the first year of life, Newell’s shearwaters do not visit breeding islands, but as they age, they will visit colonies for progressively longer periods, until they first breed at the age of six (2).
Since 1992, numbers of Newell’s shearwaters on Kaua’i have been declining. Although this decline is thought to be associated with the impacts of Hurricane Iniki, which hit the island in 1992, numerous other factors could also be implicated. Artificial lighting on the breeding islands, such as street and resort lights, is affecting large numbers of Newell’s shearwaters. Lights disorientate fledglings as they depart the island for life at sea, causing them to crash into powerlines, communication towers or other structures, or fall to the ground exhausted. Once on the ground, the small birds are vulnerable to cars, cats, dogs, starvation and dehydration, resulting in thousands perishing each year (4).
When nesting, Newell’s shearwater is vulnerable to predation from introduced mammals (4). Feral cats have been recorded killing nesting birds in their burrows (4), and rats are believed to prey on eggs and chicks (6). Also of concern is the small Asian mongoose (Herpestes javanicus), another potential predator that has recently been discovered on Kaua`i (6). Newell’s shearwater is likely to be impacted by the loss and degradation of suitable nesting habitat. Already 75 percent of Kaua’i’s natural forest has been lost in the last 150 years (4), and the remaining forest is now being impacted by introduced plants, pigs and goats (4) (6). Out at sea, overfishing of tuna species, which aid the shearwater by driving prey to the surface, may eventually affect this bird (4).
Finally, given that the majority of Newell’s shearwaters breed on a single island, this makes them highly vulnerable to the impacts of catastrophic events, such as hurricanes (4). The declines observed in this species since the hurricane of 1992 illustrate this sobering situation only too well (6).
Several conservation actions have been initiated for this Endangered bird. In 1978, a campaign to rescue and rehabilitate fallen fledglings began (4). Entitled Save our Shearwaters, this campaign recovers and releases around 1,500 disorientated shearwaters each year (2) (4). Since the early 1980s, efforts have been made to reduce the amount of glaring lights that attract and disorientate shearwaters (4). In 2006, a law was passed which requires all non-essential lights to be turned off or shielded between September and December on Kaua’i, when young shearwaters leave their nests (6), and recently, hoods (to prevent lights shining into the sky) have been installed on all lights on the island (4).
These are fantastic efforts, but yet more needs to be done to ensure the future survival of this species. Future recommended management measures include controlling introduced predators, eradicating invasive plants from the sites of shearwater colonies, and continuing to identify areas where the use of artificial lights and powerlines can be minimized (4).
For further information on the conservation of Newell’s shearwater see:
State of Hawaii – Shearwater Action Page:
For more information on this and other bird species please see:
This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
- Cetaceans: a group comprising all whales, dolphins and porpoises.
IUCN Red List (June, 2008)
- Brooke, M. (2004) Albatrosses and Petrels across the World. Oxford University Press, Oxford.
- Denny, J. (1999) The Birds of Kaua'i. University of Hawaii Press, Honolulu.
- Mitchell, C., Ogura, C., Meadows, D.W., Kane, A., Strommer, L., Fretz, S., Leonard, D. and McClung, A. (2005) Hawaii’s Comprehensive Wildlife Conservation Strategy. Department of Land and Natural Resources, Honolulu, Hawai‘i.
- Burnie, D. (2001) Animal. Dorling Kindersley, London.
BirdLife International (September, 2008)