Miskelly, C.M.; Sagar, P.M.; Tennyson, A.J.D; Scofield, R.P. 2001. A review of the birds of the Snares Islands, New Zealand. Notornis 48(1): 1-40.

Bird records from the Snares Islands between Dec 1982 and Oct 2000 are summarised. Population estimates and distributions are given for the 29 breeding species. Bird species recorded breeding on the Snares Is for the first time since 1982 were southern black-browed albatross (Diomedea melanophrys), Chatham Island albatross (D. eremita), mallard (Anas platyrhynchos), southern black-backed gull (Larus dominicanus), fantail (Rhipidura fuliginosa), and starling (Sturnus vulgaris). Fantails are now abundant on the Snares Is. Published work on the breeding chronology and breeding success of 8 intensively studied species is summarised, and new information on breeding ecology is presented for all breeding species. Sightings of 70 non-breeding and vagrant species are summarised; 34 of these were new records from the Snares Is since 1980. The total bird list for the Snares Is is now 99 species, with a further 8 species reported from boats offshore.

Bramley, G.N. 2001. Dispersal by juvenile North Island weka (Gallirallus australis greyi). Notornis 48: 43-46.

Reports of dispersal by juvenile weka (Gallirallus australis greyi) on the North Island are rare. Estimates of the distance dispersed and the rate of survival of dispersers are important factors to be considered for weka conservation. I captured 20 young weka during a 2-year study and attached radio transmitters to 4 of them. In addition, I was able to measure the distance travelled by 3 banded weka that were either recaptured or seen again, and 1 weka that was recovered dead. Newly independent weka used a part of their parental home range at first, then moved up to 3.5 km. Two-stage dispersal, where young weka leave their parents but remain close by and move away later, has been reported on offshore islands: my results are consistent with that type of dispersal. More research is needed on weka dispersal because it is likely to be linked to factors important for their conservation and management.

McKinlay, B. 2001. Counting terrestrial bird species in mixed habitats: and assessment of relative conspicuousness. Notornis 48 (1): 47-53.

Conspicuousness of terrestrial birds from a distribution study using 100 ha squares based on the New Zealand map grid was investigated. Logistic regression was used to determine the amount of time observers should spend in each square to have a 50% chance of detecting any given bird species if it was present. The analysis was conducted for 3 habitats. For 14 species of native and introduced birds, the length of time necessary to determine presence was 1 - 631 min. To ensure that most species are accounted for in future distribution studies using similar grids, it is recommended that observers spend 1 h in each square.

Pierre, J.P. 2001. Habitat use and foraging patterns of a reintroduced population of the South Island saddleback (Philesturnus carunculatus carunculatus), the first breeding season after release. Notornis 48(2): 63-71.

The benefits of monitoring habitat use patterns of translocated populations are widely acknowledged. However, this monitoring seldom occurs. Here, I report the habitat use and foraging patterns of a newly translocated population of South Island saddlebacks (Philesturnus carunculatus carunculatus) on Motuara Island, New Zealand, during the 1st breeding season after release. Reintroduced South Island saddlebacks spent most foraging time on the ground and in Pseudopanax arboreus. Foraging substrates used by male and female saddlebacks differed significantly. Saddlebacks focused foraging activities at 0-4 m above ground, and appeared to prefer to forage in larger trees, although the species composition of forested areas did not seem to influence the birds' choices of places to settle. With increasing population density, saddlebacks on Motuara Island may increase their areal foraging efficiency by using a wider range of plant species, vertically stratifying foraging locations within pairs, increasing use of smaller trees for foraging, and possibly by using scrub habitats more extensively. South Island saddlebacks appear to be highly adaptable in their choice of foraging sites and this plasticity may enhance the success of translocations.

McKinlay, B.; Smale, A. 2001. The effect of jetboat wake on braided riverbed birds on the Dart River. Notornis 48(2): 72-75.

We investigated the effect of jetboat wakes on feeding wrybill (Anarhynchus frontalis), banded dotterel (Charadrius bicinctus), black-billed gull (Larus bulleri), and black-fronted tern (Sterna albostriata) on the Dart River, Otago. We found that all species feed in areas likely to be affected by jetboat wake. On average, banded dotterel (n=8) were 43.2 mm above the water level and 4.37 m from the waters edge, wrybill (n=16) were 49mm above the water level and 0.8 m from the waters edge. Jetboat wake (n=7) extended 91.3 mm above the waters edge and on average 1 m from the edge of the river channel. The implications of the wash and the extent of the likely effect are discussed.

Armstrong, D.P. 2001. Sexing North Island robins (Petroica australis longipes) from morphometrics and plumage. Notornis 48(2): 76-80.

North Island robins are sexually dimorphic, males having darker plumage on their back and upper breast. However, males show delayed plumage maturation, and do not acquire the characteristic male plumage until after their first breeding season, 12-16 months after fledging. Therefore, sexing based on plumage alone will overestimate the proportion of females, and this may result in highly skewed sex ratios for translocations. Using measurements from robins of known sex on Tiritiri Matangi Island, I found tarsus length to be a useful indicator of sex. Of 82 robins measured, 80% of birds with tarsus length greater than 35.6 mm were male and 77% of other birds were female. If tarsus length is used in combination with plumage, it should allow sex ratios to be estimated reasonably accurately and without bias. However, additional data including wing chord measurements suggest that wing chord is superior to tarsus length for determining sex.

Parrish, R; Williams, M. 2001. Decline of brown teal (Anas chlorotis) in Northland, New Zealand 1988-99. Notornis 48(3): 131-136.

Numbers of brown teal (Anas chlorotis) present at summer flock sites in Northland, New Zealand declined 65% during 1988-99 and the species' principal range contracted to three enclaves located along 20 km of the eastern coast. Most populations underwent a period of gradual decline followed by an abrupt crash, symptomatic of prolonged recruitment failure. Drought-induced habitat and landscape change is proposed as an important agent of decline in two formerly large populations at Clendon Cove and Tutaematai. Extirpation in Northland appears imminent.

Medway, D.G. 2001. Causes of the demise of a breeding population of titi on Mangaia, Cook Islands. Notornis 48(3): 137-144.

A species of small procellariid known locally as titi, probably the black-winged petrel (Pterodroma nigripennis), nested into the historic period in burrows in the volcanic soil of the uplands of Mangaia in the southern Cook group. The demise of this titi as a breeding bird on Mangaia was probably caused by a combination of the detrimental effects of human harvesting and various introduced mammalian predators which were present on Mangaia after the arrival of missionaries in the early nineteenth century.

Moore, P.J. 2001. Historical records of yellow-eyed penguin (Megadyptes antipodes) in southern New Zealand. Notornis 48(3): 145-156.

The yellow-eyed penguin (Megadyptes antipodes) on the South Island of New Zealand was believed to have suffered a population decline that continued into the 1980s. Unpublished census results from L. Richdale (1930s-1950s) and S. Sharpe (1950s-1960s) for Otago Peninsula show that there were only 44 nests in 1940, but the number increased in the 1940s-1960s. Numbers peaked at 276 nests in the mid-1980s. Subsequent decreases and a crash to 79 nests in 1990 led to concerns for the viability of the population, but years of good survival and breeding allowed a recovery. The fluctuations were probably driven by interplays of human impacts and environmental variation. Reservation of breeding areas, revegetation, and predator control have reduced the deleterious human impacts and given the species a chance to increase numbers and withstand adverse fluctuations in the environment.

Miller, C. 2001. Long-term monitoring of a breeding colony of white herons (Egretta alba) on the Waitangiroto River, South Westland, New Zealand. Notornis 48(3): 157-163.

The population of white herons (Egretta alba) at Waitangiroto Nature Reserve has been monitored since 1944. The number of breeding adults (estimated from maximum number of nests at the height of the breeding season, and first recorded in 1958) has increased from 26 to c.100, with a concurrent increase in the number of chicks hatched and fledged. Population growth was greatest between 1964-69 and 1980-84. Chick mortality appears to result largely from the effects of westerly and southwesterly storms in October and November, although infanticide, siblicide, and low levels of predation may account for some chick deaths. The mean number of fledglings nest-1 has decreased over time as the number of nests has increased, suggesting a density dependent response. The white herons that "invaded" New Zealand from Australia in 1952 and 1957 did not appear to recruit into the breeding population.

Williams, M. 2001. Productivity and survival within two declining populations of brown teal (Anas chlorotis). Notornis 48(4): 187-195.

Brown teal (Anas chlorotis) populations at Clendon Cove and Tutaematai in Northland, New Zealand, declined catastrophically between 1993 and 1995, from 31 pairs to 1 and from 22 pairs to 8, respectively. Mean productivity was 1.8 fledglings pair-1 in both populations. Fledgling survival was almost nil with only 1 of 51 identifiable fledglings surviving to recruit into 1 population. Almost all fledgling mortality occurred within 3 months of independence. Annual adult survival was 15% at Clendon Cove and 43% at Tutaematai and most deaths occurred in October-December, immediately after breeding. At Clendon Cove, significant mortality also occurred in autumn. Destruction of breeding and refuge habitat by cattle seeking moisture during periods of drought was identified as a significant cause of decline.

Flux, I.A.; Powlesland, R.G.; Dilks, P.J.; Grant, A.D. 2001. Breeding, survival, and recruitment of Chatham Island pigeon (Hemiphaga chathamensis). Notornis 48(4): 177-206.

The Chatham Island pigeon or parea (Hemiphaga chathamensis) is an endangered species of pigeon endemic to the Chatham Islands. Effective conservation management of the Chatham Island pigeon required an understanding of its ecology and identification of the causes of decline. We studied the pigeon in their last remaining stronghold; the south-west of Chatham Island, New Zealand, between July 1991 and December 1994. We describe the nesting behaviour, nesting success, and the dispersal, survival, and recruitment of juveniles. The study was confounded by the lack of information on predator numbers or outcomes of pigeon nests from before the start of predator control activities within and adjacent to our study area. Despite a previously reported decline in pigeon numbers up until the early 1990s, during this study there was a 3-fold population increase, and only a low-level of predation by possums and rats. Other than predation, no factor which might previously have limited the pigeon population was identified. We assume that the trapping and poisoning of pest-mammals since 1989, has been sufficient to allow the population of Chatham Island pigeon to recover.

Powlesland, R.G.; Merton, D.V.; Crouchley, D.; O'Connor, S. 2001. Status and breeding biology of the Chatham Island tomtit (Petroica macrocephala chathamensis). Notornis 48 (4): 207-216.

The population status of the Chatham Island tomtit (Petroica macrocephala chathamensis) was determined for each island of the Chathams group, east of New Zealand. Also, the breeding biology of the population on Rangatira (South East Island), which is free of introduced mammalian pests, was determined from observations made during 8 breeding seasons, 1981/82 to 1988/89. The total population of the Chatham Island tomtit is estimated to be < 1000 birds: Chatham, extinct; Pitt, c. 500; Rangatira, 200-300; Mangere, 70-100; Tapuaenuku (Little Mangere Island), occasional vagrant. Regeneration of scrub and forest habitats on 3 islands is likely to lead to gradual increases in the tomtit populations there. The nesting season on Rangatira was from late September to late January, which was just sufficient time for a pair to rear 2 broods successfully. Of 378 nests, 43% were in tangles of pohuehue (Muehlenbeckia australis) vines, 16% in cavities, 12% on a branch, trunk, or stump covered in vines, and for 21% the site was not indicated. The mean height of nests was 2.7 m, and the mean duration of the pre-laying period was 5.9 days. Mean clutch size was 3.1 eggs, and incubation usually started on the day the last egg was laid (82%). Only females were seen incubating, with males feeding their mates at regular intervals. Of 97 eggs, 83% hatched, and 93% of 15 nesting attempts resulted in at least 1 fledgling each. The high nesting success, in comparison to that of mainland populations, is attributed to the absence of mammalian predators on Rangatira. Although our study provided much information for the early stages of the nesting cycle, few data are available for other aspects of the Chatham Island tomtit's breeding biology, such as length of incubation, and nestling and fledgling periods.

Flux, I.; Innes, J. 2001. A field technique for determining the sex of North Island kokako (Callaeas cinerea wilsoni). Notornis 48(4): 217-223.

North Island kokako (Callaeas cinerea wilsoni) appear sexually monomorphic. Females are, on average, slightly smaller than males in most body measurements. Mean tarsus length was significantly smaller among females at all sites and can be used to predict sex of unknown birds with up to 86% accuracy. A simple discriminant function, using tarsus and wing chord measurements, was derived which increased sex resolution to over 90% at some sites. This is sufficient accuracy to provide a useful field technique for kokako research and conservation management. Best discriminant functions for different sites are presented and their geographical limitations are discussed.

Worthy, T.H. 2001. A fossil vertebrate fauna accumulated by laughing owls (Sceloglaux albifacies) on the Gouland Downs, northwest Nelson, New Zealand. Notornis 48(4): 225-233.

A rich fossil fauna accumulated by laughing owls (Sceloglaux albifacies) during the Holocene, is described from GD101 Cave, on the Gouland Downs, northwest Nelson, South Island, New Zealand. Twenty-eight species of bird, a tuatara, 3 frogs, at least 4 geckos, 1 skink, 2 bats, and 2 fish contribute to the species diversity. The fauna includes the first inland fossil record of New Zealand dotterel (Charadrius obscurus). The taphonomy of the deposit and the diet of the owl are discussed.

Quintana, R.D.; Cirelli, V.; Benitez, 0. 2001. Nest materials of skuas and Kelp Gulls at Cierva Point, Antarctic Peninsula. Notornis 48(4): 235-240.

Use of nest materials for skuas (Catharacta spp.) and kelp gull (Larus dominicanus) was studied in the Antarctic Peninsula during the 1992-1993 breeding season. Material from 126 skua and 51 gull nests found in 10 habitat types (HTs) was analyzed. Plant censuses were conducted to evaluate the availability of species commonly used as nesting material. Skuas used mainly Polytrichum alpestre, while gulls used mainly Deschampsia antarctica. No correlation was found in the use of different nest material in skuas and gulls, indicating that they differ in their use. The narrow range of resources found in nest material suggests a selective pattern of use restricted to a few plant species. However, use of nesting material also appears linked to its availability, although skuas and gulls' preference tbr P. alpestre and D. antarctica, respectively was observed in HTs with a low and discontinuous covering of these plant species.