A stable evidence-based taxonomy is a critical requirement for the effective future conservation of the albatrosses. Recently published partial molecular phylogenies are in broad agreement with respect to the structure of the evolutionary tree for most named taxa, but the analytical methods used to create them have been seriously criticised and they must be considered provisional at best. A further problem is that their authors reach startlingly different conclusions regarding the numbers of taxa which should be recognised as species; 13 vs. 24. Here, we attempt to resolve this situation by supplying full length mitochondrial cytochrome b data presently missing for 2 taxa, carrying out thorough phylogenetic analyses meeting the requirements of published prescriptions and taking into full account other sources of new molecular data and contemporary opinions on albatross nomenclature and the status of taxa. We provide general support for the published trees and critically evaluate claims regarding how many taxa represent full species. Some genetic distances between pairs of taxa are so small that considerable weight of alternative evidence is required to support any decision leading to a recommendation to split them. We note that the empirical boundary between consensus and controversy falls at or around 1% DNA sequence divergence and further that few, if any, commentators recognise taxa that are separated by less than 0.1% as being valid species.
The kaka (Nestor meridionalis) is an endemic parrot of New Zealand, and is nationally endangered. Conservation of the species is primarily dependent on intensive control of introduced mammalian nest predators, particularly stoats (Mustela erminea) and brushtail possums (Trichosurus vulpecula). Breeding was studied in 4 sites: Waipapa (1996-2002) and Whirinaki (1998-2002) in the North Island, and Rotoiti (1997-2002) and Eglinton (1998-2002) in the South Island. In total, 145 nests were found. The proportion of radio-tagged females that bred at a site in a given year varied from 0-100%, with most breeding occurring in years of mast-fruiting or seeding by key food tree species. Kaka nested mainly in trunk cavities of live canopy or emergent trees. Egg-laying occurred from Oct to Mar, but differed between years within sites by up to a month, and was usually 2 months later at the most southern site (Eglinton) than elsewhere. Mean egg length was 41.5 mm, mean maximum breadth was 31.5 mm, and fresh egg mass was 22.6 g or 5.65% of female body weight. Clutches consisted of 1-8 eggs, most being of 3, 4 or 5 eggs (mode = 5), and mean clutch size did not differ significantly between the sites. The female alone carried out incubation, with her mate feeding her 8-12 times a day. Overall, hatching success varied from 39-66% between sites, but it also varied between breeding seasons at each site, in part due to the level of control of introduced predatory mammals. Kaka nestlings were covered in white down at hatching, and left the nest when c. 70 days old. Even when 11-20 days old, they were left unattended at night for 20-70% of time and by day for 50-85% of time. Twice females were filmed aggressively attempting to evict stoats that had killed broods in their nest cavities. Breeding productivity (proportion of eggs that produced fledglings) in the 4 study sites varied from 19% at Whirinaki (no control of predatory mammals) to 53% at Eglinton (intense control of predatory mammals). The implications of the breeding biology of the kaka are discussed in relation to conservation management of the species.
Breeding of pied shags (Phalacrocorax varius) at 2 colonies at Makara Beach, Wellington, was studied from Mar 1996, when breeding was 1st noted there, to May 2005. Pairs occupied and refurbished vacant nests rather than build new nests. The number of breeding attempts increased from 3 in 1996 to 46 in 2004, with 166 occurring during the study. New nests (n = 14) took about 3 weeks to build; most nests were used twice a year. Clutches were laid in all months, but there were 2 peaks: 61 nests (37%) in Feb–Mar and 53 nests (32%) in Aug–Sep. Overall, 76.6% were successful (fledged at least 1 nestling, n = 154 breeding attempts for which the outcomes were known), and the mean success was 1.4 fledglings nest-1. The proportion of successful breeding attempts and the mean number of fledglings produced nest-1 were similar for 1996-2000 (when the number of breeding attempts yr-1 increased from 3 to 11) compared with the 2001-2005 period (when breeding attempts increased from 15 to 46 yr-1). Of 14 breeding attempts for which clutch size was determined, mean clutch size was 3.4 (range 2-4 eggs), and mean brood size at fledging was 2.1 young (62% of eggs resulted in fledglings). The maximum number of shags counted at the colonies increased from 14 in 1996 to 68 in Dec 2003, after which numbers appeared to stabilize. However, since 2003, numbers of pied shags seen elsewhere in the Wellington region, particularly on Mana I and at Waikanae Estuary, have increased.
Stewart Island/Rakiura, the third largest island in New Zealand, has not had the large-scale forest clearance and introduction of mustelids that has had deleterious impacts on populations of native forest birds on the North and South Islands. However, Stewart Island has had 3 rat species, feral cats and possums introduced, which are known bird predators. It is likely that these species have had serious consequences for the native birds there. As no review of forest birds had been done within the past 80 years, an evaluation of changes in the reported abundance of native bird species on Stewart Island over the past 100 years was carried out, which revealed relatively recent declines and extinctions. Brown teal, rifleman, mohua, South Island kokako, falcon, Stewart Island weka and probably yellow-crown parakeets, have gone extinct on Stewart Island within the past 50 years. Birds showing dramatic declines in the past 100 years include kereru, kaka, kakapo, and robin. Populations of native birds on Stewart Island showed similar patterns of extinctions and declines as the South Island despite fewer agents of decline.
An appraisal of the conservation status of the post-1800 New Zealand avifauna is presented. The list comprises 428 taxa in the following categories: ‘Extinct’ 20, ‘Threatened’ 77 (comprising 24 ‘Nationally Critical’, 15 ‘Nationally Endangered’, 38 ‘Nationally Vulnerable’), ‘At Risk’ 93 (comprising 18 ‘Declining’, 10 ‘Recovering’, 17 ‘Relict’, 48 ‘Naturally Uncommon’), ‘Not Threatened’ (native and resident) 36, ‘Coloniser’ 8, ‘Migrant’ 27, ‘Vagrant’ 130, and ‘Introduced and Naturalised’ 36. One species was assessed as ‘Data Deficient’. The list uses the New Zealand Threat Classification System, which provides greater resolution of naturally uncommon taxa typical of insular environments than the IUCN threat ranking system. New Zealand taxa are here ranked at subspecies level, and in some cases population level, when populations are judged to be potentially taxonomically distinct on the basis of genetic data or morphological observations. In contrast, IUCN and BirdLife International bird threat rankings are assigned only at species level. This paper represents the first time that the entire modern New Zealand avifauna has been assessed from a conservation perspective. A brief analysis of patterns of extinction, threat, and rarity exhibited by the taxa listed is presented.
Pterodroma occulta was described by Imber and Tennyson in 2001 and tentatively named Vanuatu petrel. The first specimens of this bird were collected in Jan 1927, east of the island Mere Lava in Vanuatu (then New Hebrides), but their breeding grounds have remained unknown. After several exploratory visits to the Banks Islands I discovered a breeding colony of Vanuatu petrels on Vanua Lava in Feb 2009. Statements that this species breeds on Mere Lava were not substantiated.
The New Zealand storm-petrel Pealeornis maoriana Mathews, 1932 was described from 3 specimens collected in the 19th century. Since 1952 it has most commonly been considered a subspecies of Wilson’s storm-petrel Oceanites oceanicus exhibiting the ventrally streaked “Pealea” phenomenon. There had been no recorded sightings of the New Zealand storm-petrel in over 170 years before Jan 2003. Since then, observations off northern New Zealand of storm petrels believed to be this taxon have been made regularly during the austral summer. From observations and photographs, these birds appeared more similar to the New Zealand storm-petrel than to other storm petrel species occurring in the region. However, confirmation of their identity was not possible without capture. In Nov 2005 one was captured off Little Barrier Is, and 3 more were caught elsewhere in the Hauraki Gulf in Jan 2006. Analyses of detailed descriptions, photographs, and morphometric data of these birds provide conclusive evidence that they represent an extant population of the New Zealand storm-petrel. Our analyses of these data and comparison with the New Zealand storm-petrel museum specimens and 17 other Southern Hemisphere storm petrel taxa (subfamily Oceanitinae), lead us to conclude that this species is distinct.
Motuora is a highly modified island in the Hauraki Gulf that is currently being re-vegetated. It is envisaged that the island will eventually be restored to a native forest system with strong seabird influences. The island retains a small breeding population of grey-faced petrels (Pterodroma macroptera gouldi). In 2005 a survey of the accessible areas of the coastal margin was carried out to estimate the current size of the population. The survey located 406 active burrows and it was estimated that approximately 260-280 burrows contained incubating pairs. There was some evidence that active burrow numbers had increased at established breeding areas since the last survey in 1995, but differences between survey methods made comparisons difficult. Fixed monitoring plots were put in place in 2005 to provide a standardized measure of changes in burrow activity. Between 2005 and 2007 no change in the number of active burrows was discernible in the fixed plots. Longer term monitoring will be required to determine the population dynamics of the Motuora grey-faced petrels as evidence from other locations indicates that growth (if it occurs) will be slow. Consequently, seabird numbers (and associated nutrient inputs) on Motuora are likely to be below pre-disturbance levels for many decades. These results highlight the challenges of ecosystem restoration in highly modified habitats.