ARTICLES ON HAWAIIAN
BIRDS AND BIRDWATCHING AND OTHER
Newell's Shearwater (Puffinus newelli)
The Newell's Shearwater (Puffinus newells) is now considered a full species, although it was once lumped as a single species with Townsend's Shearwater (Puffinus auriclaris). The current population is estimated at about 8,000 adults, with a total population of about 10,000 or more. It nests in burrows on the grassy slopes of mountains on the island of Kaua'i and possibly O'ahu, Maui and Hawai'i in the Hawaiian Islands Archipelago. The species also once nested on Moloka'i and still may do so in small numbers. The species is listed as "threatened" under the Federal Endangered Species Act and as "vulnerable" by Collar et al. and the IUCN (1994).
Sincock and Sweberg (1969) state that "Newell's Shearwater, known as 'A'o in Hawaiian was first obtained by Mr. M. Newell on Maui in the spring of 1894 when several of the species were taken from their burrows by natives and taken alive to Mr. Newell. Munro (1941) mentioned that Mr. Alanson Bryan found skins of the 'A'o in about 1900 in the Gay and Robinson collections from Kaua'i. Bryan reported hearing the call of what he thought were 'A'o in the valleys of Moloka'i. Munro (1944) expressed the opinion that the mongoose had no doubt killed all of them that nested on Hawai'i, Maui and Moloka'i. He further stated that "It may still nest in remote valleys on the north side of Kaua'i or perhaps Ni'ihau. By some it is thought to be extinct and if so there are only about seven specimens in existence". Kaua'i as the only major island without the mongoose, has frequently been suggested as the primary nesting area of the 'A'o. King and Gould (1967) concluded that Kaua'i is now the primary and possibly the only breeding locality of Newell's Shearwater. They estimated its population on Kaua'i to be in the low thousands. Locally, the annual autumnal misfortune of the 'A'o "falling" out of the sky onto lighted highways, parks, football fields, and buildings was well known to residents on the eastern side of Kaua'i. Swedberg sent about 40 of these "downed" birds to the Smithsonian Institution in 1966."
Henshaw in his work on Hawaiian Birds , 'Birds of the Hawaiian Islands' stated that Mr. M. Newell quoted "...Two specimens were saved, one of which, the type, is in my possession, the other being in the museum of St. Louis College in Honolulu. At the time mentioned the species was numerous in the Waihee Valley and probably elsewhere on Maui, but it is to be feared that the species has since suffered from the mongoose, which is rapidly exterminating the native puffins (sic) elsewhere on the islands. At present no particulars of its habits are known".
The Newell's Shearwater is a fairly small black and white Shearwater. The upperparts are black, occasionally with a brownish hue and white underparts. The underwing is white with a narrow black border and black primary shafts on the underside. The black on the face extends to below the eye and covers the ear coverts and the lores. The white from the underparts extends onto the sides of the rump and this is very prominent when a bird is seen from above. The tail is dark and pointed. The bill is narrow and all-dark, with a hooked tip as in most Shearwater species. In flight the species is characterised by a distinctive flight-pattern which consists of rapid flapping of stiffly-held wings interspersed with short glides, and this flight pattern is quite unlike that of the much more widespread Wedge-tailed Shearwater (Puffinus pacificus), enabling identification at long range.
The species has a very distinctive and diagnostic call, which is given over the nesting colony in display flight or from the ground near the nest site. The call is a repeated jackass-like braying and crow-like calling, as well as a repeated "ah-oh". The species is usually silent at sea.
Distribution, Population and Habits
The species nests only in the Main Hawaiian Islands, mainly on the island of Kaua'i, although small numbers also probably nest on O'ahu, Maui and Moloka'i, as well as possibly on Hawai'i. On Kaua'i Most birds nest in the thickly vegetated mountain slopes in the interior of the island which drop down from the Alaka'i Plateau, although birds probably also nest in the Mokolea Mountains in northeastern Kaua'i. Nesting sites on other islands are not well known and have been little studied, making estimates of population size or nesting success almost impossible to calculate
Collar et al. (1994) state that the population is estimated at about 8,000 adults, with a total population of over 10,000. However up to 2,000 birds, mostly juveniles, are picked up each year by residents and wildlife groups on Kaua'i after colliding with urban lights and power cables on their first flight from their nest to the open ocean, and this figure would suggest that the population is higher than that estimated. Spear et al. (1994) estimated a far larger total population (135,000) and a breeding population of between 20,000 and 25,000 pairs. Although these estimates were from at-sea population monitoring the numbers involved appear extremely high and it may well be that this is an over-estimate. Ainley et al. (1995) estimate a breeding population of 14,600 pairs from data gathered in the 1980's, with the population producing 9600 fledglings a year. They further state that using a Leslie model and a mix of parameters from the Newell's Shearwater with those from the closely related Manx Shearwater, indications showed that the population was declining at a rate of about 50% every ten years.
The species arrives and leaves its burrow in the mountains during darkness and birds are seldom seen near land during daylight hours. During the day adults remain either in their burrows or at sea some distance from land. Birds are frequently encountered on pelagic boat trips during daylight, especially near to Kaua'i and Ni'ihau, further east in the chain birds are far more scarce, reflecting the nesting distribution of the species. During the early evening birds start to gather offshore and although usually birds are only seen singly or in small groups within sight of land occasionally larger rafts of hundreds of birds may be observed. As the light begins to fade birds start to head towards the land and usually gain height before they reach the coast (though not always) and will usually head in a direct line for their nesting colonies, without any of the meandering or wandering of some other species. Their direct flight means that birds are often lost quickly from view as they dart inland and gain more height, usually disappearing into the clouds which shroud their nesting sites.
Once at the nesting areas the birds may call constantly for hours on end as they fly over and around the nest site. The birds nest in short burrows excavated into the crumbly volcanic rock and ground, usually under dense vegetation. Unlike Wedge-tailed Shearwaters the species will not usually lay its eggs straight onto the ground if a nesting burrow is not available as the egg would likely become chilled or blown away from the nest site. This must undoubtedly have an effect on the numbers of birds able to nest as burrows can sometimes be in short supply, due to collapses, flooding or over-occupation of a colony. According to Harrison (1990) avian malaria has been detected in the blood of many Newell's Shearwaters recovered in Hawai'i and this may be a limiting factor to the species population in the mosquito-infested mountain slopes of the Hawaiian Archipelago.
A single egg is laid in the burrow and one adult bird remains on the egg whilst the second adult goes to sea to feed. Once the chick has hatched and is large enough to withstand the cool temperatures of the mountains both adults will go to sea to provide the growing chick with a daily supply of food.
For those interested in the full life history of the species Hawai'i's Seabirds: Natural History and Conservation by Craig Harrison (1990) covers many aspects of the species existence including the breeding season, breeding success, conservation, courtship, distribution, feeding, fledging, growth and development, incubation, longevity, movements, nest sites, population, pox, territory and vocalizations.
Collision of Shearwaters with power cables and urban lights
Every year hundreds and sometimes thousands of Newell's Shearwaters, along with dozens of Hawaiian Petrels (Pterodroma sandwichensis) are grounded by colliding with power cables or after becoming disorientated by urban lighting. Of these many are killed or injured but thanks to an island-wide initiative those individuals which are unharmed or are treatable are collected, taken to fire stations and then rehabilitated and released back into the wild. On Kaua'i up to 2000 birds may be released in a year - a number which makes up a significant proportion of the entire population of this species. It is also important to remember that most of these birds are newly fledged and on their first flight to the ocean, if the population is bereft of these young birds then the long-term outlook for the entire population could be bleak.
Telfer et al. (1987). state " Every year more than 1,000 fledglings of three threatened or endangered procellariform seabird species are attracted to bright coastal lights on the Hawaiian island of Kaua'i. These seabirds, apparently on their first flight to the ocean, become disorientated around bright lights and crash into buildings, wires, tall vegetation and vehicles. Beginning in the early 1960's this problem became increasingly acute as Kaua'i's urban areas grew and the number of high-intensity lights increased. In response we initially instructed the public to release birds by tossing them into the air near the ocean. Since 1978, however, we asked Kaua'i residents to collect and turn in the birds at 1 of 12 "Shearwater aid stations" that we set up around the island. Newell's Shearwaters began turning up under bright lights during the autumn months in the late 1950's. Thirty seven birds were collected on Kaua'i between 1954 and 1961, and in the autumn of 1967, 200 downed Shearwaters were found on the grounds of the Kaua'i Surf Hotel".
Telfer et al. (1995) state that the Save Our Shearwaters (SOS) has processed an average of 1432 fledglings per year since 1980-91 (the SOS start up years). "Considering all areas of Kaua'i, the number processed has shown no trend with annual variation largely a function of breeding success and the date of the full moon relative to the fledging peak in October... SOS data reveal that the numbers of fledglings attracted to urban lights each fall have been gradually decreasing on the southshore, where the urban corridor, until recently, long has been the most developed on the island; in contrast, on the Eastshore and especially the Northshore, where development is relatively new and has been increasing very rapidly since the 1970's, numbers of fledglings processed has also been increasing sharply. research in the urban corridor, by SOS and us, revealed that (1) about 15% of all fledglings produced each year are processed by SOS, (2) mortality of fledglings due to fallout is high (ca. 10%), but (3) mortality to adults and especially subadults...is relatively lower (0.6 - 2.1% per year)... that first breeding occurs at about age 6 and that one-year olds do not visit Kaua'i.
They estimated a breeding population of about 14,600 pairs. Using a Leslie model and a mix of parameters from the Newell's Shearwater with those from the closely related Manx Shearwater, indications showed that the population was declining at a rate of about 50% every ten years. The model also shows that the SOS program is critical to reducing the rate of population decline.
Newell's Shearwater prior to release at Kilauea Point, Kaua'i.
© Christian Melgar. 1998.
Cross-Fostering experiment with Newell's Shearwater
An experimental cross-fostering program was conducted between 1978 and 1980 as part of an overall plan to ensure survival of this threatened Shearwater. Eggs were transferred from Newell's Shearwater burrows to those of foster parent Wedge-tailed Shearwaters at Kilauea Point National Wildlife Refuge, Kaua'i during the first half of July, about 2 weeks prior to hatching. Sixty-five Newell's eggs were transferred to Kilauea Point and 25 to Mokuaeae Island (offshore at Kilauea Point). Hatching success was relatively high at Kilauea Point each year and much higher than on Mokuaeae Island in 1979. the difference was the rate of egg predation. The Common Myna (Acridotheres tristris) is a major predator of eggs of Wedge-tailed Shearwater, and so a Myna control and scare program was initiated late in the laying period and no Newell's eggs were lost. In 1979 and 1980, chicken eggs were treated with bird repellent to condition the Mynas not to eat eggs at Kilauea Point, but not on Mokuaeae. As a result 44% of the Newell's eggs were taken on Mokuaeae Island whereas only two were taken at Kilauea Point in 1980 and five failed to hatch. The overall hatching success of cross-fostered eggs (78.9%) was almost identical to that in undisturbed burrows of the nominate race of Manx Shearwater (P.p. puffinus) in Wales. Over 94% of chicks from eggs that hatched subsequently fledged.
Although the recommendation at the time (1979-1980) was that the program should be extended the lack of subsequent reports in later years of Newell's Shearwaters returning to Kilauea Point to nest or breed must be a limiting factor in the future use of this method of population stabilisation and recruitment. Another program of bringing birds to Kilauea Point during the mid - late 1990's has resulted in up to two pairs of Newell's Shearwaters returning to artificial burrows annually, as yet however (1991) no fledglings had successfully left the nest.
Observing Newell's Shearwaters in Hawai'i
This species can be observed in Hawaiian waters between early April and November, with the majority of birds being sighted between May and September. Outside of the nesting season birds are surprisingly scarce and rarely seen at sea in the waters surrounding Hawai'i, presumably the birds wander further afield in the central North Pacific although they are rarely (if ever) recorded from the North American mainland west coast or from the far western edge of the Pacific Ocean.
One of the best ways to observe the species is to embark on a pelagic boat trip from one of Hawai'i's many small harbours. Pelagics from Kaua'i are far more likely to pick the species up as this is nearest to the main breeding colonies. Any boat travelling from Kaua'i to Lehua Rock (Ni'ihau) or out for 5 - 10 miles from shore will almost certainly see this species between May and late September, with smaller numbers occurring in April and October and November. Birds are also regularly seen from boats from the other islands, especially O'ahu, but the further down the chain one travels the less likely there is of a sighting.
This is the island where there is the best chance of seeing the species, both from land at sea and of birds flying over during the evening.
Ha'ena Point: Small numbers are seen passing by here every evening, presumably many birds are flying to Hanalei Bay, although undoubtedly some also fly directly to the mountain slopes along the Na Pali coast.
Hanalei Bay: The main gathering area for Shearwaters before they fly up to the mountain slopes of the Alaka'i Plateau. Hundreds of birds may be present offshore, although often they are just beyond observational range from the shore. Birds fly inland here in larger numbers than at any other single site and so a sighting is almost guaranteed, although clear skies with a clear sunset will make observation much easier.
Kilauea Point: Although only a few individuals are usually observed each evening birds tend to be easier to observe here than at other sites due to a combination of position of The Point (most northerly on the island), visibility range (able to see as far as Hanalei Bay and the Mokolea Mountains) and the fact that a few individuals have been relocated to the area. Birds which nest in the interior usually pass straight over but may fly past the point a couple of times to orientate themselves before continuing. The position of Kilauea Point means that birds flying in over the north coast can be picked up over quite a considerable distance. Of even more interest at Kilauea Point is the fact that a small number of Newell's Shearwater chicks were relocated to the Kilauea Point National Wildlife Refuge to provide a separate population of the species. Special nest boxes were provided for the birds and for the last few years birds have returned annually to use the boxes. As of 2000 no birds had successfully nested, although eggs were laid on several occasions. It is hoped that the species will soon successfully nest at this site. To see or hear the birds at the National Wildlife Refuge stand at the "turnaround" at the refuge gate after sunset and wait for the birds to start calling loudly. On a clear night when the moon is visible you may be lucky enough to glimpse a Shearwater flying rapidly around over the refuge, although it is more likely that you will hear the birds rather than see them. It is very important not to try to enter the refuge after it has closed as this may jeopardise nesting seabirds and future access to the site.
Kealia Beach/Kapa'a: Birds pass overhead daily along the coast between the Wailua River and Kealia Beach in small numbers on their way to their nesting sites and small groups can often be seen collecting offshore earlier in the evening. Birds often collide with power cables and street lights along the coast here and during the fall many birds are picked up here dead and injured - a deadly combination of being a direct flight path to the nesting areas and being one of the most built up areas on the island.
Nawiliwili Lighthouse/Ninini Point: One of the best sites for observing the species. Birds can be seen here in large numbers (up to 500 individuals recorded) and many often pass close inshore. This location is best during a northeast wind, when many other seabirds will be present offshore as well; days when there is no wind can result in very few or no birds being recorded. Although a telescope is useful here it is easy to pick out Newell's Shearwaters by their distinctive flight and their diminutive size.
Makahuena Point: Birds are regularly recorded off the point here in fairly good numbers, most are distant but now and again a bird will close nearby.
Polihale: Birds can easily be seen from the park at Polihale, although often distant and a telescope is often very useful.
For a close up view during the fall a visit to a fire station may provide this opportunity. Birds picked up on roads and paths which have been brought to the stations for rehabilitation and release can often be seen in the small collection cages positioned outside. It is important however not to frighten or distress the birds by approaching too closely or making sudden movements in front of the cages, as the birds are likely to already be in shock. Rehabilitation cages with seabirds photo © Jim Denny.
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BYRD, G. V. and T. C. TELFER. 1984. A cross-fostering experiment with Newell's race of Manx Shearwater. Journal of Wildlife Management, 48 (1).
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HENSHAW, H.W. 1968. Excerpts from The Birds of the Hawaiian Islands. Reprinted in The Elepaio volume 29, No.3, p.21. Hawai'i Audubon Society. Honolulu, Hawai'i.
PODOLSKY, R.; AINLEY, D.G.; SPENCER, G.; DEFOREST, L. and Nur, N. 1998. Mortality of Newell's Shearwaters caused by collisions with urban structures on Kaua'i. Colonial Waterbirds 21 (1): 20-34.
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SPEAR, L.B., AINLEY, D.G., NUR, N., and HOWELL, S.N.G. 1995. Population size and factors affecting at -sea distributions of four endangered procellariids in the tropical Pacific. Condor 97:613-638. The Cooper Ornithological Society.
TELFER, T. C., J. L. SINCOCK, G. V. BYRD and J. R. REED. 1987. . Attraction of Hawaiian Seabirds to lights: Conservation efforts and effects of Moon phase. Wildlife Society Bulletin 15: 406-413.
Christian Melgar. Worthing, West Sussex, UK. 2002.