Date of this Version
Two field trials were conducted to determine the effectiveness of Avitrol® (4-aminopyridine) mixed grains 0.50% in the repelling of house finches (Carpodocus mexicana) from two vineyards in Sonoma County. In the first trial, two properties were prebaited for twelve and fourteen days respectively. After the removal of the prebait, Avitrol treated grain mixture was then placed in the bait troughs for a period of from two to four days. A count of the house finch (linnets) number visiting the troughs during the prebaiting and treatment phases of the trial was recorded. Subsequent linnet counts were made to determine the days of protection which were achieved from the treatment. In the second trial the methods were similar; however, only one of the two selected properties was treated. In both trials, trapping with a modified Australian crow trap was done when necessary to census existing house finch populations and to mitigate further crop damage. The trials indicate that Avitrol mixed grain baits can provide good long term protection to smaller vineyards with low to moderate linnet populations. In the larger vineyards with approximately 1,000 linnets, only short term control was achieved.