The effects of age, sex and season on the live weight and weight of liver, ether-extractable fats, fat-free weight and gizzard contents were examined for starlings in Canterbury, New Zealand.
The application of fensulfothiqn and parathion for the control of invertebrate pasture pests in Canterbury during March, April and May 1970 killed many birds and mammals. Two hundred and thirty-six dead birds were found after a single application of fensulfothion to 123.4 ha, and 158 birds were recovered from 78.5 ha of pasture treated with parathion. The main species killed were white-backed magpie (Cymnorhina tibicen), black-backed gull (Larus dominicanus) and harrier hawk (Circus approximans).
A population of hedgehogs (Erinaceus europaeus L.) in pasture land in Canterbury was found to vary between less than four and eight per hectare. Feeding habits were studied through stomach contents and analysis of faeces. Grass grub beetles (Costelytra zealandica) and porina moths (Wiseana cervinta), both important pasture pests, were relatively important food items. Estimates of the number of grass grubs eaten in relation to their density and that of hedgehogs in pastures show that hedgehogs are potentially capable of consuming 10-40 percent of adult populations.
The distribution of parks and reserves in the Canterbury Land District is outlined, and attention is drawn to the predominance of forest and mountain vegetation within the present network of nature conservation.
Five herbivorous introduced mammals are sympatric in the central Southern Alps. All of these species have the potential to affect conservation values, yet the Department of Conservation at present monitors and mitigates the impacts of only one. We outline ecological arguments for multi-species management of sympatric herbivore pest impacts and use the two- species system of sympatric thar and chamois to highlight the need for multi-species management of the central Southern Alps alpine pest community.
Changes in Hieracium abundance in Eastern Otago tussock grassland were examined by sampling 163 sites in 1982 and again in 1992. For Hieracium pilosella, H. praealtum and H. lepidulum, as well as Agrostis capillaris for comparison, colonisation of new sites was recorded, as well as extinction of species from sites over the 10 years, and changes in cover. H. pilosella colonised the majority of sites from which it had been absent in 1982; it disappeared from only a few sites where it had been present at very low cover.
The effects of environment and management on the composition of short-tussock grasslands and the abundance of the invasive weed Hieracium pilosella were investigated in two small catchments. Species composition and site factors were recorded on a total of 182 plots and the management history of each catchment was reviewed. H. pilosella was present on >80% of all plots, but was at an early stage of invasion in one catchment (<5% cover) and dominant in the other (25% cover).
The relationship between fleshy-fruited indigenous species and adventive weeds in the diet of 500 mist-netted birds was studied in forest remnants of differing size and degree of modification. Fruit abundance Peaked in March and April, and most fruit was either red/orange or purple/black. The physical parameters of adventive and indigenous fruits were not significantly different. Six of the 15 passerine species netted are frugivores, and of those netted 77% had eaten fruit.
Vegetation changes were investigated on 27 transects in agriculturally unimproved short tussock grasslands dominated by Festuca novae-zelandine in the Harper-Avoca catchment, Canterbury. These were remeasured at 5 or 10 year intervals between 1965 and 1990. Change was widespread. It was characterised by invasions by exotic species, declines in native species (including F. novae-zelandine), and a trend towards vegetation dominated by the flatweeds Hieracium lepidulum and H. pilosella, and the grass Agrostis capillaris.
Recent concern that honey bees may threaten natural areas by increasing weed abundances through increased pollination was investigated by reviewing the literature to determine which weed taxa surveyed from New Zealand Protected Natural Areas (PNAs) are visited by honey bees. The contribution made by honey bees to weed reproduction was assessed by checking reproductive strategies and pollination mechanisms of a subset of problem weeds. A substantial proportion of surveyed weeds in PNAs are probably visited by honey bees (43%) including half of the problem weeds.