Wills, D.E.; Murray, J.; Powlesland, R.G. 2003. Impact of management on the breeding success of the northern New Zealand dotterel (Charadrius obscurus aquilonius) on Matakana Island, Bay of Plenty. Notornis 50(1): 1-10.

Abstract The breeding success of northern New Zealand dotterels (Charadrius obscurus aquilonius) on Matakana Island, Bay of Plenty, was determined over 8 seasons (1992/93-1999/2000) in managed and unmanaged areas. Management to enhance breeding success included shifting nests to reduce the risk of flooding during spring tides and storms, and reducing predator populations of brushtail possum (Trichosurus vulpecula), feral house cat (Felis catus), Norway rat (Rattus norvegicus), stoat (Mustela erminea), and southern black-backed gull (Larus dominicanus) at dotterel breeding areas. Measures taken to reduce the incidence of disturbance by people on breeding dotterels included erecting fences around nesting areas, and speaking to members of the public about the plight of the species. The number of breeding pairs on Matakana Island fluctuated between 19 and 31 during the 8 seasons. Overall, 35.1% of 276 nesting attempts resulted in broods hatching. The main causes of nest failure during incubation were flooding by high tides or storms, and predation. The proportion of nests in which 1 or more eggs hatched was fairly stable during the 1993/94 to 1997/98 seasons at 26.1-33.3%, but was 68.0 and 51.3% in the last 2 years. This marked improvement in nesting success was attributed to the increased duration of pest control: starting before dotterel breeding began and continuing until most broods had fledged. Nesting success during incubation in managed habitat (47.5%) was significantly greater than in unmanaged habitat (19.5%). Overall, 52.6% of chicks fledged. The number of chicks fledged per season (5–33), and fledglings produced per breeding pair (0.26–1.08) increased through the study. In conclusion, we make suggestions to further promote the conservation of the northern New Zealand dotterel.

Whelan, M.B.; Hume, T.M.; Sagar, P.M.; Shankar, U.; Liefting, R. 2003. Relationship between physical characteristics of estuaries and the size and diversity of wader populations in the North Island of New Zealand. Notornis 50(1): 11-22.

Abstract The aim of this study was to associate the distribution of waders with physical attributes of estuaries and map the distribution of estuaries that have the potential to support large diverse wader populations. Maximum wader abundance and the maximum number of species recorded (1983-1994) at 94 estuaries on the North Island, New Zealand were related to physical attributes of the estuaries using General Linear Modelling techniques. Parameters describing the estuary type, area, tidal influence, catchment area, catchment rainfall, intertidal area and temperature were used as independent variables. Analysis revealed strong positive relationships between the size and diversity of a wader population and estuary area. A negative relationship between catchment runoff and wader abundance and diversity existed in some estuaries. The model predicted that relatively small estuaries (100 to 999 ha) could support large, diverse wader populations if catchment runoff was low. A map of estuaries predicted by the model to support large diverse populations of wading birds is presented. This study highlights the value of large estuaries in New Zealand in maintaining large populations and high species diversity of migratory and non-migratory waders.

Imber, M.J.; Harrison, M.; Wood, S.E.; Cotter, R.N. 2003. An estimate of numbers of grey-faced petrels (Pterodroma macroptera gouldi) breeding on Moutohora (Whale Island), Bay of Plenty, New Zealand, during 1998-2000. Notornis 50(1): 23-26.

Abstract Moutohora (Whale Island) holds the largest surveyed breeding colony of grey-faced petrels (Pterodroma macroptera gouldi).For our estimate of the breeding population, we divided the island into 16 sections within which burrow densities were approximately uniform; the surface areas of these sections were found by planimetry. Apparently completed burrows were counted in 1998-2000 within each section by plots of 2 m radius along linear transects, or by 10 × 10 m contiguous plots. The total estimate (± SE) for the island was 109,000 ± 10,000 burrows, which equates to about 95,000 pairs breeding annually, given an occupancy rate of about 87%. The population has apparently more than doubled since Norway rats (Rattus norvegicus) and rabbits (Oryctolagus cuniculus) were eradicated in 1985/87.

Kearvell, J.C.; Grant, A.D.; Boon, W.M. 2003. The orange-fronted parakeet (Cyanoramphus malherbi) is a distinct species: a review of recent research on its taxonomy and systematic and systematic relationship within the genus Cyanoramphus. Notornis 50(1): 27-35.

Abstract The taxonomic status of the endangered orange-fronted parakeet (Cyanoramphus malherbi) has been the subject of much debate since this endemic New Zealand parakeet was first described in 1857. The debate in the late 1800s and again over the past 30 years has been lively but inconclusive. We provide a summary of this debate and the most recent research into the taxonomic status of this parakeet based on mitochondrial DNA (mtDNA), assortative pairing, bill morphology, vocalisation, and comparative ecology. Based on all available scientific and historical data, we conclude that the orange-fronted parakeet is a distinct species.

Sagar, P.M.; Miskelly, C.M.; Sagar, J.L.; Tennyson, A.J.D. 2003. Population size, breeding, and annual cycle of the New Zealand Antarctic tern (Sterna vittata bethunei) at the Snares Islands. Notornis 50(1): 36-42.5.

Abstract The population size, breeding, and annual cycle of Antarctic terns (Sterna vittata bethunei) at the subantarctic Snares Islands were studied intermittently from 1976 to 2001. During the 1983/84 and 1984/85 breeding seasons the population comprised a minimum of 65 breeding pairs. Laying dates extended from mid Sep to late Mar, with peak laying in late Oct-early Nov. Clutch size averaged 1.33 (range 1-2 eggs) and clutch size did not change through the breeding season. Both parents incubated. Hatching success was 92.7% and both parents fed the young. Fledging success was 75%, and so overall breeding success was 69.6%. Chicks were fed mostly fish by both parents and 1-chick broods were fed smaller fish and less frequently than 2-chick broods. The youngest bird recorded breeding was at least 3 years old. After the breeding season (from Mar), the terns formed flocks and moulted in the vicinity of the Snares Islands. Following the completion of moult (from Apr) they tended to move offshore, only returning to the shelter of the islands during severe weather. From mid Jul, the terns tended to roost in flocks at the Snares Islands before dispersing to form pairs and defend nesting sites.

Baber, M.J.; Craig, J.L. 2003. The relationship between foraging behaviour and habitat use by South Island takahe (Porphyrio hochstetteri) on Tiritiri Matangi Island. Notornis 50(2): 59-66.

Abstract We investigated the habitat use and foraging behaviour of 3 South Island takahe (Porphyrio hochstetteri) family groups on Tiritiri Matangi Island, from Nov 1994 to Oct 1995. Takahe used habitats that offered abundant grasses, specifically grass/shrub mosaic and managed grass tracks, but open grassland was avoided. The preference was attributed to the higher risk of predation by Australasian harriers (Circus approximans) in this habitat as a result of a lack of sheltering trees or shrubs. Temporal patterns in habitat use reflected seasonal changes in food availability and breeding condition (age of chick). Most importantly, takahe family groups used the seasonally available grass seedheads in the grassland/shrub mosaic and the invertebrates in forest when chicks were young. The ability of Tiritiri Matangi to support takahe is likely to decrease as the suitable grass/shrub mosaic reverts to forest under the revegetation programme.

Baber, M.J,; Craig, J.L. 2003. Home range size and carrying capacity of the South Island takahe (Porphyrio hochstetteri) at Tiritiri Matangi Island. Notornis 50(2): 67-74.

Abstract The South Island takahe (Porphyrio hochstetteri), an endangered flightless rail, has been released on 4 predator-free islands to reduce the risk of its extinction. To determine the ability of these islands to support takahe populations, we studied takahe home range size and carrying capacity on one of the islands. We plotted the location of 4 takahe family groups (13 individuals) from Nov 1994 to Oct 1995 on Tiritiri Matangi Island. Mean home range size (95% Minimum Convex Polygon) was 20.7 ha, and tended to be smaller when the proportion of suitable habitat within each home range was higher. We estimate that Tiritiri Matangi can support up to 8 breeding pairs, based on the availability of suitable habitat and estimated individual habitat requirements. However, this number is likely to change in the future depending on the influence of population density increases and successional habitat changes on takahe spatial requirements.

Anderson, S.H.; Craig, J.L. 2003. Breeding biology of bellbirds (Anthornis melanura) on Tiritiri Matangi Island. Notornis 50(2): 75-82.

Abstract Bellbird (Anthornis melanura) breeding activity was monitored on Tiritiri Matangi Is in 1977 and 1978. The density of bellbirds breeding within the study area was 2.25 pairs ha-1. Resighting of banded adult birds in consecutive years was 69%, and less than half the pair bonds were maintained into the following season. Breeding extended from Oct to Jan, with a peak in Nov. Most nests were built in tree ferns, and the mean clutch size was 3.6 eggs. Incubation and nestling periods were c. 12 and 14 days, respectively. The female bellbird was significantly more active than the male in care of the nestlings. Measurements of chick head and wing length were correlated with age. Nest success was 44%, and daily survival rate 97%. Predation, desertion, and exposure contributed to nest failure, and re-nesting was common. The mean number of nests female-1 season-1 was 1.3, while mean reproductive success was 2 chicks fledged. Young were independent 2 weeks after fledging, and moulted to adult plumage in their 1st year. The dynamics of the Tiritiri Matangi population, when compared with other populations, suggest that breeding behaviour is a flexible response to environmental factors, and will vary between populations depending on the level of predation, competition and habitat quality.

Greene, T.C. 2003. Breeding biology of red-crowned parakeets (Cyanoramphus novaezelandiae) on Little Barrier Island, Hauraki Gulf, New Zealand. Notornis 50(2): 83-99.

Abstract The reproductive biology of red-crowned parakeets (Cyanoramphus novaezelandiae novaezelandiae) was studied on Little Barrier Island (Hauturu) during the 1989/90 and 1990/91 breeding seasons. Nests sited in cavities of pohutukawa (Metrosideros excelsa) and puriri (Vitex lucens) trees accounted for all but 1 nest which was found in a hole in the ground. Breeding activity was recorded from Nov to Mar with peak egg laying in Dec. Mean clutch size was 7.0 eggs (range 4-9). Replacement clutches were rare and only followed the loss of young broods. Female parakeets were entirely responsible for incubation that lasted about 23 days. The nestling period averaged 40.8 days (range 32-49) with about a 30% probability of an egg resulting in a fledgling. The main cause of nestling mortality was starvation. Infestation of nests by mites and predation of nestlings were also occasionally recorded. Post-fledging mortality was high, particularly in the 1st 2 weeks, and was attributed mainly to aerial predators such as morepork (Ninox novaeseelandiae). Aspects of nest and roost site characteristics, brood reduction, mortality, and vulnerability to predation are discussed in relation to the conservation of the species.

Greene, B. 2003. Fence removal benefits gannets (Morus serrator) at Muriwai, northwestern Auckland, New Zealand. Notornis 50(2): 100-102.

Abstract Mainland colonies of Australasian gannet (Morus serrator) colonies at Muriwai, northwestern Auckland, New Zealand, were counted between 1999 and 2002. Fences installed in 1981 on the landward side of the colonies were removed at the end of the breeding seasons of 1996 (southern colony) and 1997 (northern colony). Counts 3 years before and after fence removal were compared. After fence removal, the total average number of birds during the peak breeding season (December and January) increased by 65%. The increase resulted largely from an increase in the average number of pairs nesting on the northern colony, and a small increase in the average maximum number of chicks on the northern and southern colonies.

Waugh, S.M.; Cabrera, H.; Wood, G.C.; Davis, L.S. 2003. Burrow occupancy in Westland petrels (Procellaria westlandica). Notornis 50(3): 123-127.

The Westland petrel (Procellaria westlandica) is endemic to New Zealand, and nests within a restricted area of the West Coast of the South Is. Surveys of burrow occupancy rate in 2 colonies in 2001 using burrow-scopes showed an average of 21% of burrows contained a chick or egg. The rate was c. 50% of that recorded for other burrowing seabirds and surveyed using burrow-scopes. These findings may suggest that the breeding population may have declined in recent years, or that a large group of non-breeding birds maintain territories on the colonies. Further work is planned to test the 2 opposing hypotheses.

Wiltshire, A.; Hamilton, S. 2003. Population estimate for northern giant petrels (Macronectes halli) on Antipodes Island, New Zealand. Notornis 50(3): 128-132.

Northern giant petrel (Macronectes halli) populations are thought to be increasing at some locations around the world, decreasing at others. The size and status of their breeding populations within the New Zealand region, in particular, is poorly understood: reliable population estimates have never been made at 3 of the 5 breeding locations. A survey of pre-fledging northern giant petrel chicks on Antipodes Island, New Zealand during Jan 2000 yielded a count of 130. The total population was estimated to be c. 230 breeding pairs. Because of an absence of accurate historical surveys, the status of the Antipodes Is population is unknown.

Moore, S.J.; Battley, P.F. 2003. The use of wing remains to determine condition before death in brown teal (Anas chlorotis). Notornis 50(3): 133-139.

Little is known of the causes of mortality in captive-bred brown teal (Anas chlorotis) released to the wild. To test whether feeding difficulties have contributed to the poor survival of released birds, we developed a method to detect starvation using the wing fat content of brown teal. We extracted the lipids from 4 outer wing components of 17 intact brown teal carcasses. The lipid content of each component reflected the birds’ nutritional condition (based on body mass and size, and visible fat). Lipids were also extracted from the outer wing components of 7 partial brown teal carcasses, 6 of which were from captive-bred released birds whose cause of death could not be determined. All of the released teal were found to have been in very poor nutritional condition immediately before death, implicating starvation as a factor in their deaths. Improving the feeding regime of captive-bred brown teal (pre- and post-release) is likely to increase their survival.

Ferreira, S.M.; Taylor, S. 2003. Population decline of brown teal (Anas chlorotis) on Great Barrier Island. Notornis 50(3): 141-147.

The brown teal (Anas chlorotis) is a threatened duck species endemic to New Zealand, whose single remaining stronghold is on Great Barrier Island. During a study at Awana from 1985 to 1987 it was concluded that the population was stable. We evaluated this proposition by analysing counts made at flocking sites between 1985 and 2001, examining their demography, and by developing an age-specific demographic model to predict the likely persistence time of the population. Numbers of teal at flocking sites declined between 1985 and 2001 though demographic variables did not change except for duckling survival rate, which increased from 26% during 1996 to 54% during 1999. Previous predictions of stability were based on an incorrect model and our model suggests that the brown teal population will halve every 4.1 years. The decline observed since 1987 could be halted by improving adult survival rate.

Darby, J.T. 2003. The yellow-eyed penguin (Megadyptes antipodes) on Stewart and Codfish Islands. Notornis 50(3): 148-154.

Recent estimates of the number of yellow-eyed penguin (Megadyptes antipodes) throughout its range have led to a revised figure for the total population of this species. The number of breeding pairs on Stewart and Codfish Is together with the Auckland Is remain the least well known. Ground searches in 1984 -1994 on Stewart and Codfish Is suggested fewer birds than expected. The results of 102 ground searches of 61 localities and 118 beach counts (> 700 h of observations) support a lowering of earlier estimates to c. 170-320 pairs on Stewart Is and its outliers, and 50-80 breeding pairs on Codfish Is, giving a total of 220-400 pairs for this region. The relatively few breeding pairs found on Stewart Is, based on the length of coast line and hinterland area mass available, together with the small groupings, suggest that predation of adults and chicks may be a factor in the relatively low numbers of this species on Stewart Is itself.

Barré, N.; Wichatitsky, M. de G.; Lecoq, R.; Maillard, J.-C. 2003. Contribution to the knowledge of the New Caledonian imperial pigeon (Ducula goliath Gray, 1859), with emphasis on sexual dimorphism. Notornis 50(3): 155-160.

Hunters of the endemic imperial pigeon (Ducula goliath) or notou in the Forêt Plate site, New Caledonia, in Apr 2001 and Mar 2002, allowed us to collect some biological material, measurements and descriptions from 63 pigeons. The sample included 5 immature imperial pigeons, and 58 adults. Several measurements of adult birds differed significantly between the sexes: weight, body length, wing length, tail length, tarsus length, and head length and width being greater in males (n = 28) than females (n = 30). A cross-validated classification using a discriminant function analysis on these variables allowed 74 % of the birds to be correctly classified as male or female. None of the qualitative characters (colour of skin, bill, iris, feet, feathers) was different between the sexes. Sexing birds using a bio-molecular analysis proved to be 100% reliable. The small gonads and the thin wall of the midgut indicated that the notou were not breeding at the time of collection. They had completed, or almost so, their wing moult. Fruits of 22 tree species and the leaves of trees and ferns were identified in material taken from digestive tracts. No internal parasites and few external parasites — of a low pathogenicity — were recorded. These results improve knowledge of this endemic species and should be useful in this popular game bird’s conservation and management.

Imber, M.J.; McFadden, I.; Bell, E.A.; Scofield, R.P. 2003. Post-fledging migration, age of first return and recruitment, and results of inter-colony translocation of black petrels (Procellaria parkinsoni). Notornis 50(4): 183-190.

Abstract Between 1986 and 1990, 249 black petrels (Procellaria parkinsoni) close to fledging were transferred from Aotea (Great Barrier Island) 32 km west to Hauturu (Little Barrier Island) in New Zealand’s Hauraki Gulf. At the same time, 50 black petrels of similar age to those transferred were banded as controls on Hauturu and 229 on Aotea. Searches for these birds returning to breeding sites on both islands began in 1991 but three times more search effort was made on more-accessible Aotea. During their first 4.8 years of life at sea the only recovery came from off Ecuador (close to where two 6 year olds were also recovered). Since then to 2001, 32 birds have been recaptured or recovered in New Zealand. Most were first recaptured at 5-6 years old and first breeding at 6-7 years old. A maximum of 42% survived to 6 years old. Survival rates of transferred and control birds were similar. The 1990 cohort had significantly better survival than did the 1986-89 cohorts, and this cohort, just 21% of the experimental birds, contributed 43% of chicks known to have been reared by experimental birds to 2001. Neither body mass at departure nor the El Niño-Southern Oscillation was clearly related to this differential survival. Most transferees returned to Aotea; none of the 1986-89 cohorts was found on Hauturu but 2 of the 3 1990 transferees that were recaptured returned to Hauturu. Given that fledglings were always transferred at a similar stage of development, the earliest transfer of heavy fledglings was the most successful.
Keywords black petrel; Procellaria parkinsoni; Aotea; Great Barrier Island ; Hauturu; Little Barrier Island; migration; post-fledging survival; recruitment; translocation.

Hooson, S.; Jamieson, I.G. 2003. Breeding biology of the South Island saddleback (Philesturnus carunculatus carunculatus, Callaeatidae). Notornis 50(4): 191-199.

Abstract This study provides a first description of breeding biology of the South Island saddleback (Philesturnus carunculatus carunculatus) and the first comparisons with North Island saddlebacks (P.c. rufusater), using data collected from Ulva (Stewart Island), Breaksea (Fiordland) and Motuara (Marlborough Sounds) Islands, New Zealand. We found courtship and copulation behaviour to be similar to that of North Island saddlebacks. So too were nest locations, heights and materials, with nest materials determined by their proximity to the nest site. On Motuara and Ulva Islands, most nests were located in natural cavities (54% and 80%, respectively), while on Breaksea Island, 67% of nests were in flax (Phormium cookianum). In the recently established Ulva Island population, saddlebacks had a median and maximum clutch size of two and laid a maximum of two clutches. This contrasts with translocated island populations of North Island saddlebacks where up to four-egg clutches and four clutches per season have been recorded for pairs breeding in the first few seasons post- release. Incubation and brooding behaviour was like that described for North Island saddleback. A small number of yearlings bred successfully on Ulva Island (0.18 birds/ha), but no yearlings bred on Motuara (0.42 birds/ha) and Breaksea (0.42 birds/ha) islands.
Keywords South Island saddleback; Philesturnus carunculatus carunculatus; Callaeatidae; Ulva Island; Breaksea Island; Motuara Island; breeding behaviour.

Anderson, S.; Ogden, J. 2003. The bird community of Kaitoke wetland, Great Barrier Island. Notornis 50(4): 201-209.

Abstract A quantitative survey of the bird community of Kaitoke wetland, Great Barrier Is., New Zealand between May 1998 and July 2000 using 5-minute counts recorded 33 species, most of which occurred in less than 10% of counts. The commonest species were North Island fernbird (Bowdleria punctata), fantail (Rhipidura fuliginosa), silvereye (Zosterops lateralis), grey warbler (Gerygone igata), welcome swallow (Hirundo neoxena) and (collectively) the exotic finches, yellowhammer (Emberiza citrinella), chaffinch (Fringilla coelebs) and goldfinch (Carduelis carduelis). Native wetland species also recorded were spotless crake (Porzana tabuensis), banded rail (Rallus phillipensis), Australasian bittern (Botaurus poiciloptilus), pukeko (Porphyrio melanotus) and Australasian harrier (Circus approximans). Distributional analysis of the commonest species (those occurring in more than 10% of counts) showed most had some association with a particular vegetation type(s), while few showed any change in conspicuousness with season. There was little apparent movement of birds associated with phenology of the main wetland plant species. The significance of Kaitoke wetland in providing habitat for a range of native wetland bird species is recognised. The current threat to this ecosystem from introduced pests and development pressure, and the paucity of data available on native wetland bird species to inform conservation management, is discussed.
Keywords abundance; bird; distribution; season; vegetation; wetland; Great Barrier Island.

Moore, P. 2003. Southern royal albatross (Diomedea epomophora) injured by bands. Notornis 50(4): 211-220.

Abstract More than 35,000 southern royal albatrosses (Diomedea epomophora) were banded on Campbell Island from 1941 to 1998. Recoveries of 2187 birds while breeding on Campbell Island during 1994-98 included 54 (2.5%) that were injured by their bands; over all years, 195 (3.4%) injured birds and 225 others with bands fitted incorrectly were reported. Injury rates were higher for birds banded as chicks (7%) than adults (0.5%). Untrained volunteer banders from the island’s meteorological station banded up to 5200 birds annually, and in some years bands were not closed properly. The partially open bands eventually embedded in the leg or ankle, crippling the birds. Six annual banding cohorts were responsible for 83% of injuries and almost half (n=90) came from the 1979 cohort. Banding quality improved after 1982 and only two injured birds have been found from more recent cohorts. The band’s large circumference relative to its thickness may have contributed to it springing open with time, so a stronger band is recommended. For animal welfare reasons, a band repair operation should be conducted. If nothing is done, the situation should improve over the next 20-30 years as birds die, but regular band maintenance would prevent future problems.
Keywords southern royal albatross; Diomedea epomophora; bands; injury.

Imber, M.J.; West, J.A.; Cooper, W.J. Cook’s petrel (Pterodroma cookii): historic distribution, breeding biology and effects of predators. Notornis 50(4): 221-230.

Abstract Cook’s petrel (Pterodroma cookii), a New Zealand endemic, now breeds on only three islands at the extremities of its former range. Holocene fossil bones have indicated sites of 11 extinct colonies on North and South Islands, showing that Cook’s petrels preferred hills <1000 m high and 20-30 km inland. This is a forest-breeding, burrowing petrel. Atypically for a seasonally breeding gadfly petrel, some birds visit Hauturu (Little Barrier Island) nocturnally through the non-breeding season, but do not land. The breeding season extends from September to April at its northern-most colony on Hauturu but is a month later in the south at Whenua Hou (Codfish Island), where birds are heavier. The pre-laying exodus lasts about 28 days. Egg-laying extends over 38 days in the large northern colony, but barely 15 days in the smaller southern one. Incubation is mainly done in three 14-day spells. Chick-rearing takes about 87 days. Chicks attain almost twice the non-breeding adult weight. There is a desertion period of about 10 days before fledging. Pacific rats (Rattus exulans), feral cats (Felis catus) and weka (Gallirallus australis) have endangered these last colonies. Breeding success, most affected by rat predation of eggs and chicks, deteriorated seriously after extermination of feral cats from Hauturu, but improved significantly after eradication of rats from Whenua Hou. Rats are now a major threat on Hauturu. Cook’s petrels should be considered for reintroduction to suitable mainland reserves, to enhance biodiversity and restore nutrient inflows.
Keywords Cook’s petrel; Pterodroma cookii; Hauturu; Little Barrier Island; Whenua Hou; Codfish Island; historic distribution; predators; breeding biology.