The Marlborough Sounds has a coastline of 1500 km and hosts the greatest diversity of marine shag species in New Zealand. A survey of all breeding shag species was conducted in spring 2006. Apart from New Zealand king shag, 3 species were counted: spotted shag (Strictocarbo punctatus), pied shag (Phalacrocorax varius) and little shag (Phalacrocorax melanoleucos). Two other species (black shag Phalacrocorax carbo and little black shag Phalacrocorax sulcirostris) also occur in the area but were not recorded breeding. A total of 1,254 pairs of spotted shag were recorded at 193 sites, with most colonies occurring in the outer Sounds and inner Queen Charlotte Sound. Average colony size was 6.5 pairs (range 1-76 pairs), with 85% of colonies containing ≤10 pairs. The distribution of spotted shag colonies appears to be influenced by the availability of suitable cliff habitat. Breeding pied shags were found at 48 colonies, with a total of 438 pairs. Colonies were widely distributed, and average colony size was 9.1 pairs (range 1-28), with 83% containing ≤15 pairs. A total of 226 little shag pairs were found at 24 colonies, with most colonies also including nesting pied shags. Colony size was on average 9.4 pairs (range 4-24), with 75% of colonies containing ≤10 pairs. Colonies of pied shags and little shags were found mostly in native vegetation. Colonial seabirds that occur at relatively few locations can be used as indicators to establish critical thresholds for marine management and marine conservation. It is proposed that this survey provide a good baseline for such an approach in the Marlborough Sounds.
Diagnostic prey remains of Auckland Island shags (Leucocarbo colensoi) were analysed from 23 regurgitated pellets collected in August 2010 at Enderby Island, Auckland Islands. Allometric equations from a reference collection were applied to prey remains to provide estimates of prey length and wet mass. A minimum total of 1058 prey items from 7 genera were represented in pellets, with an estimated total wet mass of 13.2 kg. The mean number of prey items per pellet was 46 (range 7-90), with mean total prey mass per pellet of 589 g (range 86–1037 g). Small octopus (Octopus sp.) was by far the most important prey item and was present in all regurgitated pellets. It accounted for 57% of prey by number and 68% of prey by wet mass. Only 2 other genera contributed ≥ 5% towards the total mass of prey—red cod (Pseudophycis bachus) and triplefin (Forsterygion sp.) The overwhelming importance of octopus in the diet is unprecedented among shags for which diet composition is known.
We investigate the phylogenetic affinites of the New Zealand blue duck (Hymenolaimus malacorhynchos), a riverine specialist of uncertain relationships, using 2613 bp of DNA sequence data from 3 mitochondrial genes. Hymenolaimus has variously been considered an aberrant Anas species, or an ancient taxa in the tribe Anatini. Presently, it is placed in a highly-derived clade (Tribe Merganettini) with the shelducks. Our findings show that Hymenolaimus forms a monophyletic clade, and does not fit within any of the other duck tribes around the world. Our study also confirms convergent evolution among duck species that inhabit fast flowing rivers.
Ruru or moreporks (Ninox novaeseelandiae) are an iconic native species that are relatively widespread in New Zealand, yet little is known about populations that reside within urban areas. Here we present results from a ruru survey conducted by volunteers within the city of Hamilton, New Zealand to: 1) collect baseline data for future comparative ruru surveys, and 2) to introduce and promote ornithology to a wider audience. In addition, these data may be used to quantify the success of urban restoration projects and pest control operations, as many of the desired outcomes of those projects (e.g., increased native vegetation and reduced mammalian predators) would have a positive impact on ruru numbers. Twenty sites were surveyed in areas such as amenity parks and gullys with established vegetation. Teams of observers recorded the time and approximate bearing of all ruru vocalisations at sites for 1 h each night for 5 consecutive nights between 2000-2230 hours in late October 2011. Ruru were detected at 80% (16/20) of sites at least once over the survey period; at 13 of these sites ruru were detected on >2 nights, while birds were detected every night at 5 sites. Multiple birds were detected at 11 sites, which suggested that some may have been resident pairs and breeding. We recommend that including members of the public in similar surveys is highly desirable as it raises awareness around conservation issues and introduces ornithology to a wider audience.
We report a polymorphic population of collared petrels (Pterodroma brevipes) apparently breeding on Vanua Lava, northern Vanuatu, in the austral autumn-winter. This is one of only 5 known extant colonies of the species. One of the 2 birds captured by us matched the description of the recently described dark plumaged Pt. b. magnificens which had never been reported caught ashore previously. However, the other bird caught was a paler individual indicating that the taxon is variable in plumage colour, like other Pt. brevipes populations. We suggest that the 2 other criteria used to define the subspecies Pt. b. magnificens (body size and breeding chronology) are also questionable and require further investigation.
We report on the discovery, care, release, and post-release monitoring of the 2nd vagrant emperor penguin (Aptenodytes forsteri) recorded from New Zealand. An immature male emperor penguin came ashore at Peka Peka Beach (40° 50’ S) 56 km north-east of Wellington on 20 Jun 2011. Its condition deteriorated over the following 4 days, and it was taken into care at Wellington Zoo on 24 Jun. Following 72 days of rehabilitation, the bird was released at sea at 51° 42’ S, 78 km north of subantarctic Campbell I, on 4 Sep 2011. He was tracked, via satellite transmitter, moving south-east for 113 km until 9 Sep, after which no further signals were received. The arrival, care and release of this penguin attracted unprecedented levels of public and media interest for a vagrant bird to New Zealand.
One-legged standing (or unipedal posture) in birds was investigated with a particular focus on the role of ambient air temperature on this behaviour in a variety of wading birds and waterfowl. Waterfowl (Anas platyrhynchos and Cygnus atratus) were less likely to be observed standing on 1 leg than long-legged species of wading birds (Ardea novaehollandiae, Limosa lapponica, Platalea regia, Himantopus himantopus), perhaps because of differences in the length of their legs. Feeding behaviour and activities associated with disturbance influenced the frequency of unipedal posture. For captive flamingos (Phoenicopterus roseus) and pied stilts (Himantopus himantopus) the proportion of birds observed standing on 1 leg increased as the temperature increased from 8 to 19C. This observation contradicts the theory that unipedal posture is a behavioural adaptation to minimise heat loss on cold days. An alternative theory based on unihemispheric slow wave sleep (USWS) patterns is proposed as an explanation for unipedal posture and is recommended as a focus for future research. Our results also confirm the importance of considering differences between species in leg anatomy and activity levels to measure the effects of temperature.
There have been few studies on the temporal patterns of social behaviours and how they relate to timing of life history stages in nocturnal colonial bird species. This study focuses on the threatened Westland petrel (Procellaria westlandica; Procellariidae), to investigate temporal patterns in colonial interactions, including vocalisations and social behaviours, in the context of petrel sociality. We conducted extensive behavioural observations on the colony at different time-scales (throughout single nights, between seasons, and across years) to characterise the temporal dynamics of at-colony behaviours. These analyses show consistent temporal variation in several behavioural attributes (e.g., social interactions, vocalisations, eyes closed, body movements), with little or no temporal variation in others (e.g., self maintenance or stationary behaviours). These data provide the basis for specific predictions to test the role of social interactions between temporally varying vocalisations and social behaviours in nocturnal colonial birds.
A total of 730 variable oystercatchers (Haematopus unicolor) were recorded during a survey of the entire 1,500 km coastline of the Marlborough Sounds, New Zealand in spring 2006. This included 347 breeding pairs, 28 single birds and a non-breeding flock of 8 birds. The distribution of oystercatchers was influenced by habitat and human development, with fewer birds found in the inner sounds, where there is most development, and in the exposed outer coastline, where cliff or boulder habitat is limiting. Using similar methods of coastal surveys during the breeding season, the estimated national population of oystercatchers has increased from 2000 birds in 1970-71 to 7000 birds in 2006. This represents a population growth rate of 3.5% per annum. Winter flock counts give lower population estimates and coastal surveys are recommended for future monitoring of this species.