Show simple item record

dc.contributor.authorWatkins Nigel, G.en
dc.date.accessioned2008-05-29T00:56:24Z
dc.date.issued1999en
dc.identifier.urihttps://hdl.handle.net/10182/508
dc.description.abstractBirds are a major pest in vineyards both in New Zealand and overseas. There is a need for new behavioural research on birds' foraging habits and feeding preferences in vineyards, as much of the literature to date is anecdotal. Research on cues to birds' feeding will provide a basis on which new deterrent and control strategies can be devised. Spatial-and temporal bird damage in a small vineyard block was mapped to find if damage was correlated with grape maturity and environmental factors. Vineyard and field observations of bird behaviour using video technology combined with preference experiments aimed to establish the relative roles of grape sugar concentration and colour in avian selection. Proximity of vineyards to bird roosts affects damage levels, regardless of differing maturity between locations. The rate of damage tends to increase exponentially once grape maturity has passed a threshold of 13 °Brix. Bunches positioned closest to the ground receive more damage if blackbirds or song thrushes are the predominant pests. Both sugar concentration and grape colour were found to affect birds' feeding preference, but the importance of the two factors varied between years. Black and green grape varieties were differentially preferred by blackbirds (Turdus merula) and song thrushes (Turdus philomelos) while silvereyes (Zosterops lateralis) appeared to have no strong colour preference. It was apparent that there were other, not assessed, grape factors that also affect selection. In small unprotected vineyards that are adjacent to bird roosts the entire grape crop can be taken by bird pests. Besides removing the roosts, which can be beneficial shelterbelts in regions exposed to high winds, growers currently may have no alternative other than to use exclusion netting to keep crops intact. The differential preferences between bird species for variety characteristics suggest that any new deterrents and other strategies to deflect birds from grape crops may need to be species-specific.en
dc.language.isoenen
dc.publisherLincoln Universityen
dc.subjectforaging strategiesen
dc.subjectEuropean blackbirden
dc.subjectTurdus merulaen
dc.subjectSong thrushen
dc.subjectTurdus philomelosen
dc.subjectSilvereyeen
dc.subjectZosterops lateralisen
dc.subjectbird damageen
dc.subjectgrapesen
dc.subjectvineyard managementen
dc.subjectpreferenceen
dc.subjectcolouren
dc.subjectsugar concentrationen
dc.subjectbird behaviouren
dc.titleEcological correlates of bird damage in a Canterbury vineyarden
dc.typeThesis
thesis.degree.grantorLincoln Universityen
thesis.degree.levelMastersen
thesis.degree.nameMaster of Applied Scienceen
dc.subject.marsdenFields of Research::300000 Agricultural, Veterinary and Environmental Sciences::300300 Horticulture::300305 Oenology and viticultureen
lu.contributor.unitLincoln Universityen
pubs.organisational-group/LU
pubs.publication-statusPublisheden


Files in this item

Default Thumbnail
Default Thumbnail

This item appears in the following Collection(s)

Show simple item record