Justification of Red List Category
This species appears to have declined very rapidly on its breeding islands, principally as a result of depredation by feral cats and mongooses.Combined with longer term declines owing to a number of other threats, it qualifies as Endangered.
In the 1990s there was a pelagic estimate of 84,000 individuals (with a 95% confidence interval of 57,000-115,000) and from this the breeding population is estimated at 16,700-19,300 pairs (Spear 1995). However, a more recent estimate based on at-sea counts between 1998-2011 and Generalized Additive Models, estimates the population to be 27,011 (Bootstrap 95% Percentile, 18,254-37,125), though this estimate did not encompass the entire oceanic range of the species, and thus should be considered a minimum population estimate (Joyce 2016). Also, given the decline on Kauai and near extirpation from Maui, the population size could now be far smaller (D. Ainley in litt. 2016).
Radar data from 1993 and 1999-2001 across 13 sites indicates a 60-62% decline in numbers visiting Kaua`i, while recoveries of stranded young birds showed a 72% decline over the same time period (Day et al. 2000, 2003). Population models incorporating best estimates of breeding effort and success yielded a population decline of 3.2% annually (Ainley et al. 2001 in NSWG 2005). When variables estimating the anthropogenic mortality suffered by the species (predation, light attraction, and collision) were included, these models predicted a population decline of 30-60% over 10 years (Ainley et al. 2001 in NSWG 2005). Combining this with longer term declines owing to habitat loss, introduced predators, disorientation owing to urban lighting and collision with power-lines, the species is estimated to be declining at rates exceeding 50% over 47 years (three generations)
Puffinus newelli nests principally on the mountains of Kaua`i. Previously, up to 10% of the population was estimated to occur on islands elsewhere in Hawaii (Ainley et al. 1997), however this estimate remains unclear given the persistence of threats at these sites and declines observed on Kaua`i (N. Holmes and A. Raine in litt. 2016). Small colonies exist on Maui and Hawai`i, and possibly also on Moloka'i and Lana`i and potentially intermittent breeding on Lehua Islet (near Ni'ihau) in the Hawaiian Islands (U.S.A.) (Ainley et al. 1997, D. G. Ainley in litt. 1999, NSWG 2005); as well as on Rapa Island (French Polynesia) (del Hoyo et al. 2014). Evidence from radar observations indicate that it has been present on Maui, though surveys of suspected colonies and evidence from the number of fledglings picked up suggests it may now be all but gone from the island (D. Ainley in litt. 2016). In 2004, a nesting site was observed in the upper Pi’ina’au headwater region in the Ko’olau Forest Reserve on East Maui due to activity vocalizing (Wood and Bily 2008), but subsequent surveys appear to have been negative (D. Ainley in litt. 2016). In the late 1970s, 90 eggs were transported from burrows inland to Kilauea Point National Wildlife Refuge and placed under incubating A. pacifica. Of these, 67 fledged, and there are now several P. newelli nests at the same site, mostly as a result of social attraction using tape recordings (D. Ainley in litt. 2016). As of 2015, a total of 22 burrows have been located at this site, although only 13 were active in 2015 (N. Holmes and A. Raine in litt. 2016) and 8-9 in 2016 (D. Ainley in litt. 2016).
Estimates from pelagic surveys in the mid-1990s indicated c.84,000 birds (95% CI: 57,000-115, 000), from which the breeding population is estimated at 16,700-19,300 pairs (Spear et al. 1995). On Kaua`i, estimates range from the low thousands (King and Gould 1967) to c.15,000 breeding pairs (Ainley et al. 1997). However, recently the population has been estimated to be 27,011 (Bootstrap 95% Percentile, 18,254-37,125), based on at-sea counts between 1998-2011 and using Generalized Additive Models (although this did not cover its entire at-sea range and so should be treated as a minimum population estimate) (Joyce 2016).
The species has undergone rapid historical declines and has been declining steadily on Kaua`i (despite the fact that scattered colonies were being regularly discovered [Ainley et al. 1997]), with the most up-to-date information indicating an ongoing drop in numbers over recent decades (D. Ainley in litt. 2016). Radar data from 13 sites indicate a significant (60-62%) decline between 1993 and 1999-2001 in numbers visiting Kaua`i (Day et al. 2000, Day et al. 2003), while recoveries of stranded young birds showed a 72% decline between 1993 and 2001 (Day et al. 2003), and 75% decline from 1973 to 2008 (Harrison 2009). In addition to declining numbers, studies show a breeding range contraction, with three colonies active from 1980-1994 found to be inactive in 2006-2007 (Troy and Holmes 2008). When compared with still active colonies, inactive ones were found to be lower in elevation and composed of less native vegetation, indicating in addition to light attraction and predation, breeding habitat modification by non-native plants may also play a role in its decline (Troy and Holmes 2008). Population models incorporating best estimates of breeding effort and success yielded a population decline of 3.2% annually (Ainley et al. 2001 in NSWG 2005). When variables estimating the anthropogenic mortality suffered by the species (predation, light attraction, and collision) were included, these models predicted a population decline of 30-60% over 10 years (Ainley et al. 2001 in NSWG 2005). Combining this with longer term declines owing to habitat loss, introduced predators, disorientation owing to urban lighting and collision with power-lines, the species is estimated to be declining at rates exceeding 50% over 47 years (three generations).
It breeds at 160-1,200 m, apparently exhibiting habitat segregation from the Wedge-tailed Shearwater A. pacifica which is confined to lower altitudes and Hawaiian Petrel Pterodroma sandwichensis which tends to nest on cliffs above Newell's Shearwater (Ainley et al. 1997, D. Ainley in litt. 2016), albiet it does breed alongside Wedge-tailed Shearwaters at the translocated colony (N. Holmes and A. Raine in litt. 2016). It usually nests in burrows associated with the root structure of trees, including Ohia lehua Metrosideros polymorpha, and a dominant understory of densely matted uluhe fern Dicranopteris linearis in montane mesic forests on steep slopes (Ainley et al. 1997, T. Holmes in litt. 2007), although a minority nest in tussock-grass (D. G. Ainley in litt. 1999). Also recently found to nest in Sadleria cyatheoides dominated fern cover on East Maui (Wood and Bily 2008). Prior to the introduction of non-native predators, its nesting habitat was not restricted by the gradient of the slope (Ainley et al. 1997), and it has recently been indicated that it can nest in potentially any habitat that is cat-free (Troy et al. 2016, D. Ainley in litt. 2016). The breeding season begins in April, when birds return to prospect for nest sites and, following an exodus in late April, egg-laying in early June is highly synchronised (NSWG 2005). Pairs produce one egg, which is incubated for an average of 53-54 days, followed by a fledging period of 81-94 days (NSWG 2005). Most young fledge by November (Mitchell et al. 2005). The species's diet is not well known, although it is likely to consist of fish and squid, particularly Purpleback Flying Squid and flyingfish (Mitchell et al. 2005, Ainley et al. 2014). It forages for hundreds of kilometres offshore, often in large, mixed species flocks associated with schools of large, predatory fish that drive prey species to the ocean surface (Mitchell et al. 2005, NSWG 2005). The age at first breeding is likely to be around six or seven years (Mitchell et al. 2005).
The main threat to this species is thought to be predation (e.g. by cats, rats, dogs, Barn Owls Tyto alba and pigs) (D. Ainley in litt. 1999, Mitchell et al. 2005, NSWG 2005). Predation of adults and juveniles by cats has been documented on Kaua`i, and rats may take eggs and chicks (NSWG 2005). Another potential predator, the small Asian mongoose Herpestes javanicus, has recently been discovered on Kaua`i (NSWG 2005), and this could potentially be a greater threat than cats as its smaller size means it may be able to get down breeding burrows more easily (Duffy and Capece 2014). It is yet to establish a permanent presence on the island (D. Ainley in litt. 2016), although it has a history of incursions onto Kaua'i and one was trapped there in 2016 (N. Holmes and A. Raine in litt. 2016).
On Kaua`i, hurricanes Iwa and Iniki devastated the forests in 1982 and 1992 (e.g. Ainley et al. 1997). Given that a large proportion of the population breeds on Kaua`i, catastrophic events, like hurricanes, are a serious threat (Mitchell et al. 2005). Subsequent and ongoing habitat modification by alien invasive plant species, such as strawberry guava Psidium cattleianum, and feral pigs and goats, pose a significant threat (Mitchell et al. 2005, NSWG 2005) and have been suggested as contributing factor for the recent abandonment of some colonies (Troy and Holmes 2008, N. Holmes and A. Raine in litt. 2016). The recent establishment of the two-spotted leafhopper Sophonia rufofascia, which feeds on D. linearis, could be a further problem (Cooper and Day 1998).
During the 1980s and 1990s an estimated 70 adults and 280 subadults each summer, and at least 340 fledglings each autumn, die as a result of collisions with power-lines and communications towers, or indirectly because of light attraction (Podolsky et al. 1998, Anon. 2007). Birds attracted by artificial lighting become exhausted and fall to the ground. Once on the ground, fledglings are unable to fly and many are killed by cars or cats and dogs, and some die from starvation or dehydration (Mitchell et al. 2005). Between 1978 and 1981, more than 5,000 individuals were grounded on Kaua`i, and over 30,000 have been recovered since 1979 (Anon. 2007). On Kaua`i, approximately 1,500 fledglings are recovered annually after becoming grounded (Mitchell et al. 2005), although with the suspected steep decline on Kaua'i this number is now down (D. Ainley in litt. 2016). Collision with artificial structures (such as powerlines and wind turbines) is another key threat to this species, particularly in flight corridors for subadult and adult birds accessing inland colonies. Nine communications towers have recently been constructed on the Hawaiian Islands without proper consultation, and these are now the subject of an ongoing lawsuit (Anon. 2007). A field of wind generators was planned for Lana`i (A. Wilson in litt. 2007), where the species potentially breeds, although this was thought to be unlikely (T. Holmes in litt. 2007), and may no longer be happening (A. Raine in litt. 2016). On Hawai`i, cinder mining has resulted in habitat loss at several colonies (Mitchell et al. 2005). The species may suffer indirect impacts from the over-fishing of tuna Thunnus species, which drive prey species to the ocean surface (Mitchell et al. 2005, NSWG 2005). This could have implications for the energetic costs of foraging, with potential impacts on chick growth and fledging success (Mitchell et al. 2005, NSWG 2005). Fledglings have been found with pox lesions, suggesting that disease may be affecting breeding populations (Mitchell et al. 2005).
Conservation Actions Underway
In the late 1970s, a cross-fostering experiment was carried out at Kilauea Point National Wildlife Refuge, in which 90 P. newelli eggs were placed in P. pacificus nests (Anon. 2007). Subsequently, 30 young were fledged, and the four breeding pairs nesting there in 2006 were believed to be descendents of fostered birds (Anon. 2007). Between 2006 and 2013 colony calls were played and artificial burrows constructed to attract more nesting pairs to the refuge, where there is a low threat from collisions with artificial structures, and measures are being put in place to control alien species (Anon. 2007); and owing to this process up to 13 pairs have been recorded there (N. Holmes and A. Raine in litt. 2016). In 2015 a predator-proof fence was built at Nihoku (also within the Refuge) and artificial burrows added to the site, with the first 8 Newell’s Shearwater chicks translocated to the site in 2016 from montane colonies where they were raised to fledging (N. Holmes and A. Raine in litt. 2016). It is envisaged that up to 50 chicks will be translocated to this site over a five year period (N. Holmes and A. Raine in litt. 2016). Also since 2015, social attraction has also been employed in an attempt to save the population on Maui, and while the results are looking favourable, it is too soon to evaluate success (D. Ainley in litt. 2016).
In total, predator control and monitoring activities are now taking place at six colonies on Kaua'i and involve the control of cats, rats, pigs and Barn Owls as well as monitoring the effectiveness of these activities through the use of cameras and acoustic monitoring devices (N. Holmes and A. Raine in litt. 2016). On Kauai', Barn Owl control is also been undertaken at a further 5 colonies located along the Na Pali coast, Kalaheo/Kahili and Hanalei valley (N. Holmes and A. Raine in litt. 2016). The effectiveness of Barn Owl control is being monitored through the deployment of acoustic recording devices via helicopter in management areas (N. Holmes and A. Raine in litt. 2016).
There is an active programme to control lights across Kaua'i, and disorientated fledglings are recovered and released, although few of these birds have subsequently been recovered (NSWG 2005). Lighting on some buildings has been designed to reduce collisions (Ainley et al. 1997). A ruling brought by the U.S. Fish and Wildlife Service in 2006, under the U.S. Endangered Species Act, has enforced a campaign running since 2005, in which all non-essential lights on Kaua`i are required to be turned off or shielded between 15 September and 15 December when young birds leave their nests (Appel 2006). The island's electricity company is helping by darkening all of its 3,000 street lights, and shielding or turning some of them off. The company has also started incorporating a range of measures to reduce powerline collisions; including moving lines underground, lowering lines, fitting diverters to lines, and testing a ‘laser fence’ on key lines to make them more visible to birds moving at night (N. Holmes and A. Raine in litt. 2016). Significant improvements have been made in reducing light attraction and collision (T. Holmes in litt. 2007), and over 30,000 downed birds have been rescued through the Save Our Shearwaters (SOS) programme since the 1980s (Harrison 2009). While most have been banded and released only a couple dozen recoveries have ensued and therefore, whether this program is effective is not known (D. Ainley in litt. 2016). In 2010, four environmental groups sued a hotel development, which was responsible for over one quarter of all downed birds as a result of light pollution. Several other suits have been brought for violations under the Endangered Species Act (ESA) (Harrison 2009). However, there is still a considerable amount of developing and existing infrastructure that needs to be modified. It is not expected that the threat posed by artificial lighting will ever be eliminated (T. Holmes in litt. 2007). There is an ongoing programme to identify new colonies suitable for terrestrial conservation efforts (predator control, habitat restoration), further refine ornithological radar and other monitoring methods (Mitchell et al. 2005, NSWG 2005).
33 cm. Medium-sized shearwater, generally black above and white below. Undertail-coverts white basally, black distally, therefore appearing white (the last is the most useful field character). Similar spp. Townsend's Shearwater P. auricularis, but little or no range overlap. Hints Feeds at ocean fronts along the Equatorial Counter Current. Typical low fast flight of smaller shearwaters, but wingbeat slower than Audubon's Shearwater P. lherminieri.
Text account compilers
Symes, A., Anderson, O., Isherwood, I., Ashpole, J, Butchart, S., Westrip, J., Stattersfield, A., Benstead, P., Calvert, R., Taylor, J., Stuart, T.
Telfer, T., Wilson, A., Raine, A., Holmes, N, Ainley, D., Pimm, S., Pratt, H.
BirdLife International (2018) Species factsheet: Puffinus newelli. Downloaded from http://www.birdlife.org on 20/06/2018. Recommended citation for factsheets for more than one species: BirdLife International (2018) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 20/06/2018.