Reducing blackbird damage to newly planted rice with a nontoxic clay-based seed coating
At 3 sites in Chambers County, Texas, the estimated sprout loss in 1-ac plots sown with clay-coated rice seed averaged 17.0% compared to 36.5% in adjacent 1-ac control plots. In one field, bird use of the control plot was 14 times that of the treated plot. Average feeding rates of red-winged blackbirds (Agelaius phoeniceus) were 1.5 seeds/min and 8.4 seeds/min in the treated and control plots, respectively. Roadside counts of territorial male redwings and evening flightline counts of birds going to roost indicated a depredating population consisting mainly of nonbreeding, roosting birds early in April with increasing proportions of breeding birds as the rice-planting season progressed. The results of this study are consistent with previous laboratory findings and with predictions from foraging theory. Further development and field testing of the seed coating will be required before the technique becomes generally available as a method for reducing bird damage to sprouted rice.