Food preferences of the bellbird (Anthornis melanura), an endemic honeyeater, were determined by comparing the proportional use of plant species for nectar, fruit, and invertebrate feeding with the proportional availability (foliar cover) of plant species in forest remnants on the Port Hills, near the city of Christchurch, New Zealand. Of 529 feeding observations throughout the year, 56% were on invertebrates, 29% on nectar, and 15% on fruit. Invertebrate feeding predominated in all months except August to November, when nectar feeding predominated. Kunzea ericoides, Fuchsia excorticata, and Hoheria angustifolia were used more than expected from their foliar cover for invertebrate feeding, while F. excorticata, Sophora microphylla, Pseudopanax arboreus, and Phormium tenax were used more than expected for nectar feeding, and Coprosma robusta and Myrsine australis more than expected for fruit feeding. Little nectar was available in winter, which may explain why some bellbirds moved from the hills to the city at the end of the breeding season. However, more research is needed on the influence of temperature on these movements and on the resources used by bellbirds in the city.
On 5 years between 1969 and 2006, counts were made of birds seen and heard along a 2.3 km transect through a central suburb of Wellington City. A total of 14,461 birds of 26 species were encountered, including 10 native and 16 introduced species. Silvereye (Zosterops lateralis), sacred kingfisher (Halcyon sancta) dunnock (Prunella modularis) and rock dove (Columba livia) numbers remained similar over the 5 counts. By contrast, counts of tui (Prosthemadera novaeseelandiae), fantail (Rhipidura fuliginosa) and grey warbler (Gerygone igata) rose between 1988-89 and 2005-06. New Zealand pigeons (Hemiphaga novaeseelandiae) and bellbirds (Anthornis melanura) were 1st detected in 2005. The number of mallard (Anas platyrhynchos), song thrush (Turdus philomelos), chaffinch (Fringilla coelebs), blackbird (Turdus merula), goldfinch (Carduelis carduelis) and greenfinch (Carduelis chloris) increased more than 3-fold between the earliest and latest counts. Increases in the numbers of most native and introduced species may have resulted from a possum control programme that began throughout the Wellington district in the 1990s and to the establishment of the nearby Karori Wildlife Sanctuary (‘Zealandia’). Common starling (Sturnus vulgaris) and black-backed gull (Larus dominicanus) counts fell after 1971 as did the number of Australian magpies (Gymnorhina tibicen) between 1989 and 2005. Between 1969-71 and 1981-2, house sparrow (Passer domesticus) counts fell 37%, the figure remaining low until 2006. The coincidence of this decline in house sparrows with similar declines in the northern hemisphere is discussed.
Kowhai Bush in the Kaikoura region represents an important wildlife reserve for some native forest bird species. It is home of 1 of the few populations of brown creepers (Mohua novaeseelandiae) and South Island robins (Petroica australis) in lowland forest in the Canterbury region. Here, I present results from 275 five-minute point counts that were conducted at Kowhai Bush from October until December from 1999 to 2001. I compare these data with those collected by Gill (1980) in the same months of 1976 at similar sites. These comparisons reveal that the observed abundance and composition of the species at Kowhai bush has changed between 1976 and 1999-2001. Overall, there was a decline in bird abundance between 1976 and 1999-2001 and there was a significant difference in bird abundance between the 2 habitats in which counts were undertaken at Kowhai Bush. At a species level, there were dramatic declines (>50%) in the observed abundances of brown creepers and South Island robins whilst blackbirds (Turdus merula), redpolls (Carduelis flamea), and European goldfinches (C. carduelis) had more modest, but still significant declines. These declines were offset somewhat by large increases (>50%) in the observed abundances of silvereyes (Zosterops lateralis), and song thrushes (Turdus philomelos) and significant increases in the observed abundances of bellbirds (Anthornis melanura) and chaffinches (Fringilla coelebs). I discuss a number of factors that might be responsible for these changes.
Mohua (Mohoua ochrocephala) are endemic to the South Island of New Zealand but they have declined in both range and abundance. The causes of decline include predation from introduced predators and forest clearance. Mohua have survived in reasonable numbers in the Dart Valley in west Otago. In this paper we describe the relationship between the presence of mohua breeding territories and vegetation at a 1 ha scale within low altitude, red beech-dominated forest. The extent of shrub or regeneration was found to have the strongest association with the presence/absence of breeding mohua. Other factors which increase leaf volume, such as forest-edge and broken canopy were also important in explaining the presence of mohua. Milling was found to have a long lasting negative impact (>70 years) on mohua presence. Management which reduces grazing and increases the shrub and regeneration forest component is likely to increase mohua carrying capacity.
An annotated checklist of birds recorded or reported on the Aleipata Is, Samoa is presented. Nu’utele and Nu’ulua Is were the focus of an attempt to eradicate Pacific rats (Rattus exulans) in 2009. The data presented are from bird surveys intended to provide baseline information to determine the effect of rodent eradication on the bird fauna. Fanuatapu or Namu’a Is were surveyed as experimental controls. A total of 42 species were recorded or reported, comprised of 24 species of land birds (including 3 introduced species) and 18 species of seabirds and shorebirds. Morphometric data are also presented from Friendly ground-doves (Gallicolumba stairi) that were removed from Nu’utele I and held in captivity during the rat eradication attempt.
Information on the relevant spatial scale for controlling pest birds causing significant crop damage is generally lacking. Here, we assess the potential of 2 radiotracking systems (hand-held vs. elevated twin-Yagi antennae) for monitoring pest bird ranging behaviour on and around an arable farm. Radio-transmitters were fitted to 19 European greenfinches (Carduelis chloris) in the summer and 25 house sparrows (Passer domesticus) in the winter. Greenfinches were most likely to be detected in or near Brassica seed crops, particularly on the study farm, but 12% travelled large distances (>3 km) between Brassica crops in the landscape. Even though house sparrow home ranges were widely dispersed across the landscape, most overlapped with the farm boundary and were positively associated with woody vegetation. Relative to hand-held antennae, the elevated twin-Yagi system increased the detection radius for tagged birds from 100 m to 2000 m and also the number of location data, albeit over a more restricted area.
Orange-fronted parakeets (Cyanoramphus malherbi) are New Zealand’s rarest parakeet species with a global population of less than 500 individuals on remnant mainland populations and reintroduced populations on offshore islands. Since there is limited information about habitat preferences by this species on offshore islands I characterised habitat use on Maud Island, where captive-bred parakeets were introduced in 2007. I compared the vegetation characteristics of 29 plots (each 25 m2) where parakeets were encountered and 23 plots randomly selected. Parakeets were observed foraging in 96.6% of the plots. Plots used by parakeets showed significantly higher density of stems under 20 cm dbh and a higher canopy than random plots. Used plots also tended to have greater canopy cover and lower understory and ground vegetation covers. These results indicate that orange-fronted parakeets use ecotones of broadleaf coastal forest-manuka scrub, and pine plantations-manuka scrub for foraging highlighting the potential value of islands with mixed patches of these vegetation types as future refuges for this critically endangered species.
The diet of the Australasian gannet (Morus serrator) at Farewell Spit, New Zealand, was studied by the analysis of 70 regurgitations collected from the 1995 to 2001 breeding seasons. Surface schooling pilchard (Sardinops neopilchardus) was the main prey, followed by anchovy (Engraulis australis). The composition of the diet was similar in most seasons examined except in 1996 in which anchovy was the main prey item. Such a change in diet could be linked with a pilchard mass mortality in New Zealand in August 1995. The estimated annual prey consumption by birds at the Farewell Spit gannetry was 852 tonnes. Although annual catches of pilchard and anchovy by commercial fisheries in the area are still relatively small, an increase may interfere with prey availability, and in turn, increase competition between marine predators and influence the breeding success. Our analyses of diet are consistent with previous studies showing that Australasian gannets as flexible foragers and they highlight their importance as bioindicators of fish stocks in New Zealand.