Between 2002 and 2011, Buller’s albatrosses (Thalassarche bulleri bulleri and T. b. platei) accounted for 34% of albatross interactions in New Zealand trawl fisheries. However, the relative impact of commercial fisheries on each taxon is uncertain as identifying individuals by morphology is challenging. The aim of this research was to develop a genetic identification method for the 2 taxa. To this end, DNA was isolated from blood samples collected from a total of 73 birds breeding at northern Buller’s albatross colonies on the islets of Motuhara and Rangitatahi (total n = 26) and southern Buller’s albatross colonies located on Solander Island and North East Island (total n = 47). The degree of genetic differentiation between northern and southern Buller’s was estimated by using DNA sequences from a 221 bp segment of the mitochondrial Control Region. The genetic structure between northern and southern groups was high (pairwise ΦST = 0.621, P < 0.001). A Bayesian assignment method was used to determine provenance of individuals randomly sampled from fisheries bycatch (n = 97). All bycatch individuals were assigned with maximum probability to either the northern (n = 19) or southern taxon (n = 78; P = 1.00). This study demonstrated that sequences from the mitochondrial control region could reliably be used to assign individuals to either northern, or southern breeding populations, and can be used for determining the provenance of seabird bycatch.
Observer call count surveys are utilised throughout New Zealand to monitor kiwi populations. The development of affordable autonomous acoustic recorders by the Department of Conservation has enabled the collection of large quantities of digital data. Utilising call count data from the North Island brown kiwi (Apteryx mantelli) monitoring programme at Whenuakite from the 2010 and 2015 survey periods, a retrospective comparison between data collected by human observers and acoustic recorders was undertaken. Both survey methods indicated an increase in the number of kiwi calls per hour between the 2010 and 2015 surveys. The overall ratio of the number of calls per hour detected by acoustic recorders to those detected by human observers was 1:1.52. Results from the occupancy modelling indicated that the average detection probability for human observers was almost twice as high as that for acoustic recorders. Furthermore, increasing the number of sites for monitoring kiwi populations improved the associated level of precision of the derived occupancy probability estimates. Adjusting the survey design to the underlying characteristics of the kiwi population are therefore important to gain reliable estimates of their population trajectory.
Zealandia (Karori Sanctuary) is a forest sanctuary which is surrounded by a predator-exclusion fence, and is situated in the Wellington city town belt, New Zealand. Following eradication of introduced mammals from within the fence in 1999, 10 species of endemic forest birds were reintroduced between 2000 and 2011, and 2 other species recolonised naturally. Five-minute bird counts were used to assess changes in the Zealandia diurnal forest bird community over 2 time periods: 1995-98 to 2002-05, and 2002-05 to 2013-16, as well as changes over the full 21 year period. Tui (Prosthemadera novaeseelandiae) was the only bird species present before the fence was completed that showed a significant, year-round positive response to mammal removal. Following the recreation of a diverse and abundant endemic bird community post-2005, detection rates for most of the species that were present before 1999 declined significantly. This included highly significant declines in detection rates for 3 native bird species: silvereye (Zosterops lateralis), grey warbler (Gerygone igata) and New Zealand fantail (Rhipidura fuliginosa). These results suggest that populations of the most common and widespread native and introduced birds are only weakly limited by mammalian predation, but can be rapidly outcompeted by restored endemic bird species if predators are removed. The forest bird community in Zealandia is now more similar to that on nearby Kapiti Island (the source site for many of the bird species translocated to Zealandia) than it is to the bird community that existed at the site before the fence was built.
This paper summarises the variations in breeding periodicity in the Australasian – South Pacific region, including recent evidence contrary to previous knowledge. Birds shown to breed in the Samoan islands throughout the year are white-tailed tropicbird (Phäethon lepturus), white-rumped swiftlet (Aerodramus spodiopygius), buff-banded rail (Gallirallus philippensis), brown noddy (Anous stolidus), white tern (Gygis alba) and wattled honeyeater (Foulchaio carunculata). In addition, crimson-crowned fruit-dove (Ptilinopus porphyraceus), blue noddy (Procelsterna caerulea), cardinal honeyeater (Myzomela cardinalis) and Polynesian triller (Lalage maculosa) breed in at least 9 months of the year. The Samoan whistler (Pachycephala flavifrons) has been found breeding in 8 months and the Samoan starling (Aplornis atrifusca) in 7 months of the year.
Over 11 years, the presence of bird species detected within a garden in Kaikōura, New Zealand, were recorded on a weekly basis. Of the 19 species, Eurasian blackbird (Turdus merula merula), house sparrow (Passer domesticus domesticus) and common starling (Sturnus vulgaris vulgaris) were most commonly detected followed by silvereye (Zosterops lateralis), the most commonly detected native bird. New Zealand falcon (Falco novaeseelandiae), Australian magpie (Gymnorhina tibicen) and California quail (Callipepla californica brunnescens) were each seen once. Others recorded were bellbird (Anthornis melanura melanura), chaffinch (Fringilla coelebs), common redpoll (Carduelis flammea), dunnock (Prunella modularis), European goldfinch (Carduelis carduelis britannica), European greenfinch (Carduelis chloris), grey warbler (Gerygone igata), red-billed gull (Larus novaehollandiae scopulinus), song thrush (Turdus philomelos), South Island fantail (Rhipidura fuliginosa fuliginosa), yellowhammer (Emberiza citrinella) and welcome swallow (Hirundo neoxena neoxena). Ten species exhibited significant seasonal variation; 4 showed significant increases and 2 decreases over the 11 years of the study. This study has shown that simple presence/absence observations of a species on a weekly basis can provide an index of numbers, and demonstrate seasonal movements and medium-term changes of bird species within an urban garden.
We compared summer counts of water-birds (November–January, 2012–2016; mainly Anatidae, Phalacrocoracidae, Rallidae, Laridae) at 2 small, shallow, urban lakes set in parkland surroundings: Western Springs Lake (Auckland) and Henley Lake (Masterton), New Zealand. We recorded 25 species of water-birds; 17 at Western Springs Lake and 22 at Henley Lake, with 14 species in common. The average total densities (and biomasses) were 61 birds/ha (113 kg/ha) at Western Springs Lake, significantly higher than the 40 birds/ha (95 kg/ha) at Henley Lake. Ducks (Tadorninae, Anatinae) made the biggest single contribution to numbers at both lakes (40–60% of total water-bird density). Swans and geese (Anserinae) were less common than ducks but because they were heavier birds they accounted for 60–70% of total biomass, and were therefore the main consumers of food and producers of droppings. Introduced water-birds made up 60–70% of the density at both lakes, and 80–90% of the biomass, with no significant differences between lakes. The presence of some native species (in significantly greater total density and biomass at Western Springs Lake), and breeding of the endemic New Zealand scaup at both sites, illustrate the potential conservation value of New Zealand’s small urban lakes.
A national census of breeding black-billed gulls (Larus bulleri) conducted across New Zealand in 1995‒98 estimated 48,000 nests, however the methodology used was unclear. In 2013, the New Zealand threat status for the endemic black-billed gulls was changed to Nationally Critical, based on estimates of recruitment failure causing population decline. To inform future threat classification, the breeding population was re-estimated using aerial surveys to locate, photograph, and count breeding black-billed gulls across New Zealand in 2014‒2016. Large spatial gaps in nest count data during 2014/15 and 2015/16 did not allow for annual variability to be taken into account across the 3 seasons, but the 2016/17 survey successfully covered the entire country. Ground counts of nests were conducted at 16 colonies to determine a correction factor of 0.90 to apply to aerial photograph counts of apparently occupied nests. A total of 60,256 nests were found, with 33,703 nests in Southland and 20,675 nests in Canterbury. The North Island was surveyed on the ground and had 992 nests. Historical survey methods were reviewed, highlighting the inaccuracies of using nest densities or applying factors of gulls/nest to total bird counts based on photographs, as well as only counting individual birds on aerial photographs. Historical data likely overestimated numbers of breeding birds, and the inconsistencies of previous surveys make trend analyses difficult. Key recommendations for future counts include: (i) carrying out ground surveys before flights to determine the breeding stage of birds and hence the optimal time to fly; (ii) taking high resolution and zoomed in photos; (iii) carrying out ground nest counts immediately after flights to determine a correction factor; and (iv) using the same observers for all counts to maintain consistency.
Seabird bycatch data collected between 1996 and 2016 in commercial fisheries within the New Zealand Exclusive Economic Zone (EEZ) were analysed to determine if male and female grey petrels (Procellaria cinerea) have different at-sea foraging distributions during the breeding season. Data collection includes the return of bycaught (killed) seabirds from commercial fishing vessels by government fisheries observers. A total of 408 bycaught breeding grey petrels with known sex (214 males, 194 females) were analysed for a locational and seasonal sex bias. Data were also examined to determine whether where carcasses were returned from sea, there were different proportions of males and females captured by different fishing methods: offshore bottom longlining, surface longlining, and offshore trawling. There was no significant difference in the totals of male and female grey petrels returned from fishing operations, but capture locations for the sexes varied widely. More males than females were caught in April, May, August, and September. July showed a reverse trend, while June was the only month with no difference in captures between sexes. More males than females were caught in offshore bottom longliners and trawlers, with the opposite for surface longliners. This study emphasises the importance of a large-scale approach to capture locations and season when analysing impacts of fisheries on seabird populations, and highlights different foraging areas according to sex during the breeding season. Spatial segregation has important management implications as changes in fisheries practice in foraging areas may affect the sex ratio of the grey petrel population.
We assessed the impact of interspecific interactions on the breeding success of the South Georgian diving petrel (Pelecanoides georgicus; SGDP), a Nationally Critical seabird species, by monitoring 20 burrows at Codfish Island (Whenua Hou), with remote cameras. Additionally, we tested the utility of remote cameras to study the breeding biology and activity patterns of the SGDP by pairing 5 remote cameras with RFID readers. We recorded 7 different species at SGDP burrow entrances. The common diving petrel (P. urinatrix) likely caused two monitored burrows to fail. These results suggest that remote cameras are useful tools to study such interactions. However, the cameras had extremely low SGDP detection rates (mean = 10.86%; se = 7.62%) when compared to RFID readers. These low detection rates may be explained by the small body size and the speed at which SGDPs enter/leave burrows. Therefore, remote cameras, or at least the model and setup we used, appear unsuitable to study breeding biology and activity patterns in this seabird species.
We report Records Appraisal Committee (RAC) decisions regarding Unusual Bird Reports received between 1 January 2015 and 31 December 2016. Among the 113 submissions accepted by the RAC were the first New Zealand records of northern fulmar (Fulmarus glacialis), Herald petrel (Pterodroma heraldica), red-footed booby (Sula sula), laughing gull (Larus atricilla) and magpie-lark (Grallina cyanoleuca), the first breeding records for Australian wood duck (Chenonetta jubata) and glossy ibis (Plegadis falcinellus), and the second accepted records of shy mollymawk (Thalassarche cauta cauta), great shearwater (Puffinus gravis) and Cape gannet (Morus capensis). Other notable records included a pair of white-winged black terns (Chlidonias leucopterus) breeding in the Mackenzie basin, and the first record of pukeko (Porphyrio melanotus) from the Snares Islands. In addition, notable influxes of brown booby (Sula leucogaster) and great frigatebird (Fregata minor) occurred during 2015-16.