The remnant wild populations of the critically endangered orange-fronted kākāriki (Cyanoramphus malherbi) are restricted to 3 North Canterbury valleys where they co-occur with the yellow-crowned kākāriki (C. auriceps). Mixed pairs of Cyanoramphus kākāriki species have been documented throughout the genus, but the extent to which orange-fronted and yellow-crowned kākāriki mate assortatively, particularly when one species outnumbers the other, remains unclear. Here, we investigate the level of assortative mating between orange-fronted and yellow-crowned kākāriki. Based on 355 confirmed nests during 1999-2011, 99% (n = 351) were pure pairings and 1% (n = 4) were mixed pairings. With one exception, the ratio of orange-fronted to yellow-crowned kākāriki encountered during annual surveys ranged between zero and 0.78. These results indicate that the 2 congeners exhibit assortative mating, even when the orange-fronted kākāriki is outnumbered by yellow-crowned kākāriki. The low levels of mixed pairing we observed suggests that the reintroduction of orange-fronted kākāriki should not be precluded to sites where yellow-crowned kākāriki already occur.
Monitoring of wetland birds was undertaken at Lake Ellesmere/Te Waihora during the post-breeding period in February 2006, 2007 & 2008. Census totals were 38,726, 39,917 and 39,175 individual birds over the 3 years, respectively, and 46 wetland bird species were recorded. Nine species had a maximum count exceeding 1000 individuals, including 11,245 grey teal (Anas gracilis), 10,651 black swan (Cygnus atratus), 5776 pied stilt (Himantopus himantopus), 4899 Canada goose (Branta canadensis), 3405 Australasian shoveler (Anas rhynchotis), 1873 banded dotterel (Charadrius bicinctus), 1640 paradise shelduck (Tadorna variegata), 1592 black-billed gull (Larus bulleri) and 1389 mallard/grey duck (A. platyrhynchus/A. superciliosa). Fourteen species were recorded in numbers that met or exceeded the 1% Ramsar international significance criterion: Australasian crested grebe (Podiceps cristatus), black cormorant (Phalacrocorax carbo), white heron (Ardea modesta), black swan, paradise shelduck, grey teal, Australasian shoveler, pied stilt, black stilt (Himantopus novaezelandiae), banded dotterel, wrybill (Anarhynchus frontalis), black-billed gull, black-fronted tern (Childonias albostriatus), and Caspian tern (Hydroprogne caspia). Lake Ellesmere also supported populations of migratory bird species that are uncommon in New Zealand including curlew sandpiper (Calidris ferruginea), sharp-tailed sandpiper (C. acuminata), red-necked stint (C. rufficolis), Pacific golden plover (Pluvailis fulva) and white-winged black tern (Childonias leucopterus). When compared to other coastal wetlands in terms of bird numbers, Lake Ellesmere ranked as the most important site in the Canterbury Region.
We used data from 3 sources to examine the population size and trend of Salvin’s albatrosses (Thalassarche salvini) breeding on Proclamation Island, Bounty Islands, New Zealand. Island-wide counts of breeding birds during incubation resulted in totals that declined 14%, from 3065 in 1997 to 2634 in 2004. A count of breeding albatrosses over part of the island in 2011 indicated a further decline of 13% between 2004 and 2011, and an overall decline of 30% between 1997 and 2011. Additional counts on part of Depot Island indicated a decline of 10% in the numbers of breeding pairs between 2004 and 2011. Daily observations of 70 nests showed that hatching spanned the period from 5 to 21 November 1997, with a median of 15 November, apart from 5 eggs that had not yet hatched by the end of the study period. Based on the banding and recapture of chicks banded in March 1985 annual survival was estimated at 0.926. The scale of the decline estimated in this population has resulted in the conservation status of Salvin’s albatross being upgraded from nationally vulnerable to nationally critical.
Discriminant function analysis (DFA) was used to determine gender and geographic variation in the morphometrics of white-chinned petrels (Procellaria aequinoctialis) measured from fisheries bycatch in New Zealand. Samples were divided into 5 clusters based on capture location. A DFA model was created using adult breeding birds presumed to be from the 2 main locations at the Auckland Islands and Antipodes Islands. Geographic variation in head and bill, skull width, culmen, culmen depth at base, culmen width at base, right and left mid-toe and claw, tail, and right and left wing was found between birds presumed to be from the ‘Auckland’ and ‘Antipodes’ clusters, with ‘Antipodes’ birds being generally larger than ‘Auckland’ birds. Gender variation in head and bill, skull width, culmen, culmen depth at base, culmen width at base, minimum bill depth, right and left mid-toe and claw, right wing, right and left tarsus existed for ‘Auckland’ birds. Gender variation in head and bill, skull width, culmen, culmen depth at base, culmen width at base, minimum bill depth, right and left mid-toe and claw, and tail existed for ‘Antipodes’ birds. Birds in the other 3 clusters were classified as originating from the Auckland Islands or Antipodes Islands. The clustering suggested that birds from the Auckland Islands tended to forage mostly north and west, whereas birds from the Antipodes Islands foraged mostly towards the north. There were large overlaps at Puysegur Point and particularly the Chatham Rise of birds from both breeding locations. This study shows the usefulness of bycatch necropsies, and emphasises the need for further studies in geographic variation and sexual dimorphism at all New Zealand breeding locations.
The Chatham Island duck (Anseriformes: Anatidae: Anas chathamica) had a pronounced and rugose enlargement to the tip of the processus extensorius at the proximal end of its carpometacarpus. This “carpal knob” was the equal in size of those found in some much larger waterfowl (e.g., steamer ducks, Tachyeres sp.), and was disproportionately larger than those of all other New Zealand waterfowl. The knobs on 20 carpometacarpi examined all showed evidence of continuous bone deposition at their tips and their use as weapons is implied. Comparisons with other duck species having similarly prominent and rugose carpal knobs suggests the Chatham Island duck maintained long-term pair bonds and occupied combined feeding and breeding territories year-round which both sexes defended belligerently.
Banded rails (Gallirallus philippensis) were surveyed in saltmarshes and mangrove fringed habitats at Onerahi, Whangarei, New Zealand. A total of 13 sites were surveyed 3 times per year around sunset during late spring in 2004, 2007 and 2013. On average 4.41 calls were heard per hour. Banded rails were detected at 12 sites with between 0.01 and over 2 ha of saltmarsh and extensive mangroves, but not a saltmarsh site lacking mangroves. Occupancy models favoured those with no change in occupancy state, seasonal detection, and there was with some support for random colonisation of sites. Records from Awaroa Creek indicate that rails can be detected from late afternoon calls throughout the year. Surveys should include the half hour before until at least 10 minutes after sunset.
The South Island kokako (Callaeas cinerea) was officially declared extinct in 2007, with the most recent report accepted by the Ornithological Society of New Zealand’s Rare Birds Committee, being in 1967. However reports of potential observations of South Island kokako continued to appear. We compiled a total of 241 reports between January 1990 and June 2012. These reports were categorised into 6 categories depending on the details provided by observers. The most highly ranked reports required identification of the wattles which are the most distinguishing feature of South Island kokako. The 13 reports from the highest category were submitted to the Bird Threat Ranking panel in June 2012 and, based on this evidence, the species was then reclassified from “extinct” to “data deficient”. The most compelling 11 reports were then submitted to the Ornithological Society of New Zealand’s Records Appraisal Committee (RAC). One report was accepted as a South Island kokako while 2 were deemed to be of North Island kokako. This paper reviews all available reports of the South Island kokako from 1990, the assessment process and a map of the distribution of reports. Our analysis of these reports suggests that the South Island kokako is extant.
The breeding ecology and reproductive traits of brown booby (Sula leucogaster etesiaca) were studied in Gorgona Natural National Park, Colombia. Adult morphometrics, egg dimensions, chick growth and nesting site characteristics, were examined at 3 locations in the park. As with other subspecies, brown boobies in Gorgona exhibit reversed sexual dimorphism. The female booby reaches about 80 cm in length, its wingspan measures up to 150 cm, and they can weigh up to 1,300 g. The male booby reaches about 75 cm in length, its wingspan measures up to 140 cm, and they can weigh up to 1,000 g. First-laid eggs were heavier and bigger than second- or third-laid eggs. Growth of brown booby chicks fit a natural log equation: body mass (g) = 0.8773 ln * days + 3.3895. A variety of nesting aggregations was found, and their relationship with the other marine birds nesting in the area is discussed.
I conducted observations on the diet of the Floreana mockingbird (Mimus trifasciatus) during its breeding season in February and March 2011. The Floreana mockingbird is a critically endangered species restricted to Gardner and Champion Islets off the coast of Floreana Island, in the Galápagos Islands, Ecuador. During 11 days, 172 feeding bouts of adult and nestling mockingbirds were observed. The majority of feeding bouts of adults (31%; 19 feeding bouts) involved the consumption of nectar and pollen of Opuntia megasperma. Another important food item consisted of Lepidopteran caterpillars (27%; 17 feeding bouts). The majority of food items fed to nestlings consisted of Lepidopteran caterpillars (26%; 29 observations), followed by adult spiders (19%; 21 observations). The reintroduction of the species to its historical range on Floreana Island is currently being planned with an emphasis on the control or eradication of invasive cats and rats. To identify key areas for reintroduction, a study on the year-round diet of the species as well as availability and variability of food items is recommended. Nectar and pollen of Opuntia megasperma was an important dietary item for the species during its breeding season. This slow-growing plant species was widespread on the lowlands of Floreana Island but introduced grazers removed Opuntia from most of its range. In the context of the potential reintroduction of this species to Floreana Island, it is important to establish if this high-energy resource is key for breeding, and consideration should be given to a supplementary food program as it has been successfully implemented for bird species elsewhere.
The monitoring of endemic birds during the control of introduced mammalian predators is a common practice at community-based conservation projects in New Zealand. We describe long-term trends of endemic passerines monitored using the presence-absence technique during the control of stoats (Mustela erminea) and brushtail possums (Trichosurus vulpecula) in the Flora Valley, near Nelson, New Zealand. Data collected over an 8 year period by Friends of Flora, a community-based organisation, suggests that bellbirds (Anthornis melanura) significantly increased, while South Island robin (Petroica australis), tomtit (P. macrocephala) and rifleman (Acanthisitta chloris) populations showed little or no change, and grey warblers (Gerygone igata) significantly decreased. All species showed a greater increase during the first 4 years of the survey compared to the second 4 years, which suggests that meso-predator release of rats may have occurred from ~4 years after the start of the surveys. The presence-absence technique is simpler to conduct than the more commonly used 5-minute bird count method, and thus may be better suited for use by the community sector in similar situations.
We present counts of white blood cells of wild and clinically normal red-crowned parakeets (Cyanoramphus novaezelandiae) from 2 island populations in New Zealand. Total white blood cell counts on slides prepared in the field and counts of relative proportion of basophils, eosinophils, heterophils, lymphocytes and monocytes were determined for 33 individuals caught on Little Barrier Island and 48 individuals caught on Raoul Island. Mean haematological parameters were: total white blood cells 6.85 cells x 109/L, lymphocytes 5.0 x109/L (74.0%), monocytes 3.5 x109/L (5.7%), eosinophils 4.6 x109/L (6.4%), basophils 1.9 x 109/L (3.1%), and heterophils 9.9 x109/L (14.7%). Raoul Island parakeets had significantly higher counts of white blood cells, lymphocytes, and heterophils than Little Barrier Island parakeets, possibly reflecting latitudinal differences. Males showed significantly higher counts of white blood cells and lymphocytes than females. White blood cell counts on slides prepared in the field represent an inexpensive and straightforward technique to determine variation in the levels of each cell type and to assess the physiological state of healthy and diseased individuals. This information is useful for veterinary clinicians, wildlife managers, and conservation biologists who increasingly require methods for health assessment, disease diagnosis, and screening for pathogenic microorganisms on species of conservation concern.
Twenty five bird species were recorded following 2 brief winter visits to the southern Kermadec Islands during 2002 and 2006. Of these, 15 were seabirds and 10 land or shorebirds. Rapid changes in the dominant vegetation cover occurred between 1988 and 2002. Ferns replaced grass and sedge swards over much of the island, and although this succession was rapid, the distribution of woody species (the presumed historical dominant cover) did not change, most likely due to limited seed sources, Pacific rat (Rattus exulans) predation, and competition for space from other species. Possible impacts of these changes on the avifaunal composition of Macauley Island are discussed. Following the presumed eradication of Pacific rats from Macauley Island in 2006, recommendations are made for future vegetation and bird monitoring.
Opportunities to monitor natural island ecosystem recovery following the eradication of introduced predators are rare, and provide a useful comparison for recovery programmes aided by active habitat restoration and species translocations. We present an assessment of the current avifauna on Burgess Island, Mokohinau Group, 2 decades after kiore (Pacific rat; Rattus exulans) removal. The 4 most abundant land bird species we recorded are red-crowned parakeet (Cyanorhamphus novaezelandiae), bellbird (Anthornis melanura), tui (Prosthemadera novaeseelandiae) and silvereye (Zosterops lateralis), all New Zealand native taxa. Our records confirm that 46 species now utilize the island’s habitats, compared with 24 species reported from the literature during the last decades of rat infestation. We also confirm breeding of 9 seabird species by 2011, only 4 of which maintained breeding populations on Burgess Island prior to rat eradication. More than 20 years after predator removal, Burgess Island hosts a rich avifauna, and provides a valuable example of natural recovery following predator eradication without any further active restoration measures.
Numbers of bellbird (Anthornis melanura), an endemic honeyeater, counted along transects in forest remnants on the Port Hills near the city of Christchurch, New Zealand, increased since the initiation of intensive mammalian pest control in 2006. Bellbird counts also increased along transects in bush reserves and along a 6.5 km cycle route in the city itself, probably as a result of spill-over from source populations on the Port Hills, because few bellbirds breed in the city. In contrast, counts of bellbirds in domestic gardens in the city did not increase, perhaps because of the continued presence of introduced mammalian predators and/or lack of suitable habitat. We suggest the increased abundance of bellbirds in forest remnants on the Port Hills was likely the result of mammalian pest control but the lack of ‘no-treatment’ areas means we cannot rule out other causes of the increase such as changing habitat and food availability.
Calls and playback-response behaviour of breeding wedge-tailed shearwaters (Puffinus pacificus) were studied at Muttonbird Island, Coffs Harbour, New South Wales, Australia. Burrow calls were recorded from 45 females and 60 males. Male calls averaged higher in fundamental frequency and longer in note lengths than female calls, although ranges overlapped. Playback experiments demonstrated sexual recognition, with incubating females mostly responding to female playbacks. Males responded to both female and male calls. Ratios of between- to within-subject variation suggested that individual vocal signatures could be encoded in timing and some frequency parameters. Playback experiments demonstrated a “dear enemy” effect, where shearwaters in burrows were more responsive to stranger rather than neighbour calls. Wedge-tailed shearwater calls are informative and further studies are encouraged for other southern hemisphere breeding shearwaters.
Royal spoonbill (Platalea regia) nestlings (n = 158) were colour-banded between 1990 and 2005 at Green Island, Otago and Wairau lagoons, Marlborough. A total of 75% and 84% of Otago and Wairau birds, respectively, were resighted between 1991 and 2012. The pattern of independent resightings (n = 737) indicates that adult royal spoonbills in New Zealand undertake repeated seasonal inter-island migration, moving north to wintering sites (mainly Parengarenga, Rangaunu and Whangarei, up to 1200 km away), then relocating to the south again in summer to breeding sites. Most juveniles move as far north as adults, although a third of juveniles from Wairau were seen in winter in the Nelson region, a distance of < 100 km away. Juveniles and immatures (< 2 year old) remain in northern locations in summer, and return as adults (2 years and older) to their natal area. In summer all adult birds banded in Otago were resighted only in Otago, which indicates a high degree of philopatry. In contrast, a third of nestlings banded at Wairau were resighted as adults in the Otago area, indicating a southward natal dispersal. The annual survival rate is estimated to be 0.89 and 0.92 for Otago and Wairau birds, respectively. The oldest bird seen alive was 18 years and 3 months.
It is difficult to locate and monitor populations of the New Zealand falcon (Falco novaeseelandiae) because the terrain they occupy is frequently inhospitable and the traditional method of walking transects lines to locate nest sites is arduous and time consuming. For this reason we developed and trialled a low-priced broadcasting system that amplifies pre-recorded vocalisations to attract falcons, which we then used to locate their nest sites. We tested the system on 20 falcons in the Kaingaroa and Pan Pac forests on the North Island. Both sexes responded but males responded more frequently. We conclude that the system can rapidly and accurately locate falcons in a large plantation forest during the summer breeding season.