Assessment and management of pest bird species

Abstract

Adelaide Hills grape growers suffer heavy losses of fruit and income through damage by birds. In many seasons around 40% of bunches have bird pecks and for individual blocks damage of more than 90% has been recorded. Seeking effective management they decided to compare control measures and quantify damage through the season.

Summary

Six vineyards were chosen for the exercise, one each in Lenswood and Meadows and two each in Eden Valley and Balhannah to capture any sub-regional differences. These incorporated eight varieties (Chardonnay, Riesling, Sauvignon Blanc, Viognier, Cabernet Franc, Cabernet Sauvignon, Merlot and Shiraz), which were sampled and scored for bird damage. Other work included relating percentage of bird damage to the tool or combination of tools used (e.g. scare guns, scarecrows, netting and other means) and the recording of grower observations.

Observations in the season in question (2000) were that the main species doing damage were the Adelaide Rosella, Red Wattlebird, Silvereye, Little Raven and Common Starling, with the latter being seen less frequently than in previous seasons. Total damage was thought to be significantly greater across the region than in 1999 without apparent reason.

Sub-regional differences were not significant and nor was the percentage damage across grape varieties. It was found that no single technique other than well-applied netting could stop damage altogether although losses would have been even greater if nothing was done. Another pointer for management resulting from the project was to implement measures early as greatest losses occurred where there were delays until closer to harvest. It was also found that better estimates of final losses at harvest could be made if daily rates of new damage were monitored.