A technique to estimate bird damage in wine grapes

Bird damage is a world-wide problem in agriculture. Measurement of such damage is an important first step in its effective management. We develop a visual assessment technique and a progressive sampling strategy using 5 strata and suggest sample sizes necessary to achieve an estimate of bird damage within a standard error of 5%. This strategy improved sampling efficiency by 67%, 79% and 80% compared to stratified systematic, standard systematic and random sampling. With an average cost of under $(AUS) 6 per block this technique is a rapid inexpensive method to estimate bird damage to vineyards and has application to most crop-bird situations.