Tests of the effectiveness (primarily reduced plant damage) of U-12171 to repel linnets from, or reduce the amount of feeding damage on, Gem hybrid broccoli suggest that: 1) concentrations above 1.50 lb./acre deterred avian depredations whereas lower concentrations did not; 2) the "hop-scotch" feeding pattern of linnet groups may have contributed to repellency since high concentrations in one area may act as a barrier to other areas; and 3) U-12171 efficiency may be markedly affected by chemical coverage of the plant, the number of applications made, and application timing relative to crop maturity.

The ability of birds to thermoregulate under a variety of environmental conditions is necessary for their survival. The ability of European starlings to thermoregulate was investigated, finding that this species has a pronounced regular daily cycle of deep body temperature with a range of about 4.5°C. This cycle is likely the result of reduced metabolism and muscular activity during nighttime. A number of experiments of thermoregulation were conducted to better understand the possibility of using wetting agents or other techniques to prevent the birds’ feather insulation from protecting their ability to survive cold weather. We became increasingly impressed with the possibilities of using wetting agents as a possible tool to control birds by application to bird roosts, even under relatively mild climatic conditions that prevail in California.