New Zealand

The relative importance of birds and insects as pollinators of the New Zealand flora

Native birds may have been underestimated as pollinators of the New Zealand flora due to their early decline in abundance and diversity on the mainland. This paper reconsiders the relative importance of birds and insects as pollinators to eight native flowering plants, representing a range of pollination syndromes, on two offshore island refuges. Experimental manipulations were made on five of these plant species to assess the relative effectiveness of bird and insect visitors as pollinators.

Brushtail possum (Trichosurus vulpecula) diet in a north Westland mixed-beech (Nothofagus) forest

We quantified brushtail possum (Trichosurus vulpecula) diet in a mixed Nothofagus fusca-N. menziesii forest in north Westland. Diet comprised 49 food items of which four (Aristotelia serrata, Muehlenbeckia australis and Weinmannia racemosa foliage, and W. racemosa flowers) contributed 68%. The canopy dominant Nothofagus species were a minor diet component (<1%), while wood, fungi and bark were a small but consistent part of diet (10.1%).

Cattle grazing and the regeneration of totara (Podocarpus totara var. waihoensis) on river terraces, south Westland, New Zealand

Totara-matai forests are an under-represented forest type in Westland, relative to their original extent, and require protection and enhancement where possible. This study examined the regeneration of totara on gorse-covered river terraces of the Whataroa and Waiho Rivers, on a site grazed by cattle at Whataroa, and ungrazed sites at both locations. Totara is regenerating prolifically at all sites. Tall-seedling densities were significantly higher at the grazed Whataroa site than at the ungrazed Whataroa site.

Managing biodiversity information: development of New Zealand's National Vegetation Survey databank

The National Vegetation Survey (NVS) databank is designed to safeguard the investment of millions of dollars spent over the last 50 years collecting, computerising and checking New Zealand vegetation data and to optimise the potential knowledge gains from these data. Data such as these can be synthesised across a range of spatial and temporal scales, allow novel ecological questions to be considered, and can underpin land management and legal reporting obligations.

Lack of pre-dispersal seed predators in introduced Asteraceae in New Zealand

The idea that naturalised invading plants have fewer phytophagous insects associated with them in their new environment relative to their native range is often assumed, but quantitative data are few and mostly refer to pests on crop species. In this study, the incidence of seed-eating insect larvae in flowerheads of naturalised Asteraceae in New Zealand is compared with that in Britain where the species are native. Similar surveys were carried out in both countries by sampling 200 flowerheads of three populations of the same thirteen species.

Increased predation on pukeko eggs after the application of rabbit control measures

We have been studying the social behaviour and ecology of pukeko (Porphyrio porphyrio) for over five years at a study site in the lower Taieri River, Otago New Zealand. After an application of rabbit poison in 1995 and the illegal release of rabbit haemorrhagic disease (RHD) in 1997, there was strong anecdotal evidence that rabbit (Oryctolagus cuniculus) abundance on and around our study site had been substantially reduced.

Mortality of North Island tomtits (Petroica macrocephala toitoi) caused by aerial 1080 possum control operations, 1997- 98, Pureora Forest Park

Aerial poisoning operations with carrot or cereal baits are used to control brushtail possum (Trichosurus vulpecula) populations in New Zealand forests for ecosystem conservation and to stop the spread of bovine tuberculosis to cattle and deer herds on adjacent farmland. Although various measures have been implemented to reduce the incidence of bird kills, dead birds continue to be found after poison operations.

Social and spatial structure and range use by Kaimanawa wild horses (Equus caballus : Equidae)

We measured horse density, social structure, habitat use, home ranges and altitudinal micro-climates in the south-western Kaimanawa ranges east of Waiouru, New Zealand. Horse density in the Auahitotara ecological sector averaged 3.6 horses.per km² and ranged from 0.9 to 5.2 horses.per km² within different zones.

An assessment of the probability of secondary poisoning of forest insectivores following an aerial 1080 possum control operation

Assays for the toxin sodium monofluoroacetate (compound 1080) were undertaken on arthropods collected from toxic baits after a brushtail possum (Trichosorus vulpecula) control operation in Nothofagus forest in central North Island, New Zealand. The 1080 concentrations measured (mean 57 mu g per g, max 130 mu g per g) are considerably higher than those reported by other researchers who collected arthropods randomly after control operations.

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