Anne M. Stewart

The foraging of New Zealand honeyeaters

Abstract New Zealand has three species of honeyeaters, all of which feed on nectar, fruit, and ‘insects’. There is disagreement between published data and those becoming available from long-term studies on the relative proportion of these items in the diet. The effect of factors such as body size, dominance status, degree of movement, and time of year on diet and foraging behaviour are outlined, and predictions of differences between species and between sexes are made. A brief comparison of foraging in relation to the flora is made between New Zealand and Australian species.

Social dominance in communal Mexican jays Aphelocoma ultramarina

Abstract Social dominance among members of seven social units of communal Mexican jays ( Aphelocoma ultramarina ) was studied at feeding stations during the non-breeding season. Hierarchies were generally linear. Males were usually dominant to females and there was a tendency for the oldest male in each unit to be the most dominant adult. An unusual pattern of high social status of yearlings was observed. We attribute the high social status of yearlings and adult males to different causes. Adult male dominance is probably related to competition for breeding opportunities within each social unit. We tentatively interpret the dominance of the yearlings in terms of payoff asymmetries and parental facilitation.

Selection of fungal antagonists for biological control of onion white rot in New Zealand

Abstract Six fungal species were selected from a total of 76 on the basis of their antagonism to the onion white rot pathogen, Sclerotiurn cepivorwn, in dual culture. Gliocladium roseunt, G. virens, Trichoderma viride and Coniothyrium minitans exhibited their antagonism by competing successfully with the pathogen for space and nutrients whilst Chaetomium globosum and Penicillium expansion released antibiotic substances into the agar medium which inhibited the growth of S. cepivorwn at a distance. Four of the six test fungi were also able to colonise and degrade sclerotia of the pathogen. Gliocladium roseum was tolerant of the dicarboximide fungicides, iprodione, vinclozolin and procymidone. None of the antagonists were pathogenic on onion seedlings in vitro and they therefore show promise for use as biocontrol agents against onion white rot.

Reproductive biology of Phormium tenax: A honeyeater-pollinated species

Abstract The reproductive biology and pollination of Phormium tenax was studied on Tiritiri Matangi Island and in Auckland, in the northern part of New Zealand. P. tenax reproduces asexually by offsets and sexually by large inflorescences. Offsets are monocarpic and inflorescences are terminal. Adjacent inflorescences often originate from the same genetic clone and each inflorescence usually carries many open flowers at the same time. Flower crops varied substantially from year to year. Flowers are protandrous hermaphrodites that exhibit partial dichogamy and herkogamy. The pollen or the stigma are presented sequentially for initial contact with floral visitors. Nectar rewards are greatest during the male phase of flowering. Results of controlled pollinations show that the plant preferentially outcrosses. Seeds are either large or small with the former predominating from outcrossed and natural pollinations. The capsules formed from self pollinations were rarely retained unless overall levels of pollinatio...

A review of kiwifruit pollination: Where to next?

Abstract The likely role of various pollination vectors is considered in the context of flower anatomy and the published results of past experiments. A number of insects visit flowers of both female and male vines but there is as much evidence implicating wind as there is for an insect vector. Most experiments that investigated a likely role of wind alter wind flows and are confounded by the presence of honey bees. Similarly, evidence taken as support for the role of honey bees is confounded by the action of wind. Recent studies suggest that individual bees tend to work the flowers of one sex of vine or the other. Existing methods of measuring pollination effectiveness in kiwifruit are also questioned as is our understanding of incompatibility responses. An experiment that can help resolve these problems is outlined briefly.

Factors affecting pollinator effectiveness in Feijoa sellowiana

Abstract Feijoa sellowiana (Myrtaceae) was studied under cultivation in New Zealand, California, and Japan, to determine which floral visitors are the most effective pollinators. A large range of insects and birds visited feijoa flowers to collect pollen or feed on the sugary petals. Estimation of pollen deposited on stigmas showed that only large birds deposited sufficient compatible pollen to initiate fruit development. An exclusion experiment confirmed this. Observations of the behaviour and size of the floral visitors explained why insects and smaller birds are ineffective pollen vectors. In orchards with high densities of large birds, flowers were visited at earlier stages but, even at lower densities, visits were sufficient to ensure pollination. In orchards that lacked birds, fruit set was minimal. Bird visitation was greater at the edges of blocks and, in large blocks, fruit set was significantly lower in the centre of the block. Studies of animal movements indicated that large birds such as black...

Movements, status, access to nectar, and spatial organisation of the tui

Abstract Movements of tui (Prosthetnadera novaeseelandiae) breeding on Tiritiri Matangi Island were followed and related to changes in nectar access. The island has limited nectar sources and birds must move to gain access to nectar year round. All tui leave the island, although the extent and timing of movement varies for different individuals. Tui return for breeding but again the timing of the return varies for individuals. Nectar sources were typically concentrated in both time and space, and access was related to individual asymmetries such as sex, residential status and age. These same asymmetries also relate to the timing of individuals movements, and where individuals nest relative to nectar sources. At concentrated food sources, access was determined by an absolute social hierarchy. Although tui defend exclusive feeding territories, breeding territories are not exclusive and access to nectar is determined by distance to nest site. Such variability in spatial organisation is related to a continuum...

Use of demethylation inhibiting fungicides (DMIs) for the control of onion white rot (Sclerotium cepivorum Berk.) in New Zealand

Abstract The demethylation inhibiting (DMI) fungicides, tebuconazole and triadimenol, both of the triazole group, were evaluated for the control of white rot (Sclerotium cepivorum Berk.) on onion (Allium cepa L). Both fungicides, applied as foliar sprays, gave a high degree of white rot control, effecting reductions in disease of up to 85% ofthat in untreated plots. When applied as a soil surface spray immediately after sowing, tebuconazole provided a high level of protection all season. The greatest degree of control was obtained from a combination of seed treatment with procymidone (a dicarboximide fungicide), followed by foliar sprays of either procymidone, tebuconazole, or triadimenol. Tebuconazole was unsuitable for seed treatment, causing high seed and seedling mortality. For maximum control of white rot, a combination of seed treatment and foliar sprays should be used. The triazoles—tebuconazole and triadimenol are suitable alternatives to procymidone for foliar sprays.

Innovation or Multiple Copies of the Same Lottery Ticket: The Effect of Widely Shared Knowledge on Organizational Adaptability

Marketing literature suggests that a market orientation has a positive effect on a firm’s performance and innovativeness. This paper applies biological metapopulation theory to describe how a high dispersion of market information and significant shared homogeneous knowledge may reduce the evolutionary adaptation and the creation of successful new products. Empirical results derived from survey data support the theory that organizational information processing routines associated with a market orientation are not always the same as those required to facilitate organizational adaptability, contrary to previous assertions in the marketing literature.

PREDICTING PRO-ENVIRONMENTAL ATTITUDES AND BEHAVIORS: A MODEL AND A TEST

The level of public commitment to environmental sustainability is unclear; most people appear inactive in terms of effective pro-environmental behavior despite optimistic reports from public opinion polls. Mounting degradation is evidence that pro-environmental behavior has declined or at least has grown insufficiently to make a difference to environmental degradation rates. There has been a call for a fresh approach to resolve accelerating degradation. We take up this challenge and suggest that most people live in urban environments low in functional natural values. Consequently they do not understand that their continued existence depends on naturally functioning ecosystems. We investigate the effect of direct experience of a naturally functioning ecosystem (versus a constructed environment) on conservation attitudes and rates of pro-environmental behavior. Results suggest that frequent experience of a naturally functioning ecosystem was more strongly linked to conservation attitudes and pro-environmental behavior than frequent experience of a constructed environment (such as a zoo).