U.S. Department of Agriculture: Animal and Plant Health Inspection Service


Date of this Version

January 2007


Published in Proceedings of the 12th Wildlife Damage Management Conference (D.L. Nolte, W.M. Arjo, D.H. Stalman, Eds). 2007.


We developed a fast and simple method to detect presence or absence of DRC-1339 (CPTH: 3-Chloro-p-toluidine Hydrochloride) in birds that fed on DRC-1339 bait sites. We compared the effectiveness of the colorimetric method to the previously published analytical method using birds collected from DRC-1339 bait sites in Louisiana and Texas. We also conducted tests with caged red-winged blackbirds (Agelaius phoeniceus) to determine if time from consumption of DRC-1339-treated bait to death and time from death to colorimetric analysis affected test results. The colorimetric assay was effective in detecting the presence or absence of DRC-1339 in birds collected from bait sites. In the tests with caged birds, the method resulted in the detection of four grains of treated rice consumed up to 120 minutes post consumption, but failed to detect 1 grain of treated rice consumed at 120 minutes. Frozen samples of 4 treated consumed rice grains could be detected up to 90 days post collection.