Drc-1339 and Drc-2698 Residues in Starlings: Preliminary Evaluation of Their Effects on Secondary Hazard Potential

INTRODUCTION DRC-1339 (3-chloro-4-methylbenzenamine HCI) is the active ingredient in Starlicide Complete, a commercial bait used to control starlings (Sturnus vulgaris) at animal feedlots throughout the U.S. Because of the recent widespread use of this product, particularly within the wintering range of many raptors, they and other avian or mammalian scavenger or predator species may be exposed to large numbers of dead or dying starlings and blackbirds (Icteridae) throughout the winter roosting season (November-March). Acute toxicity data are available for five species of raptors and a number of mammals indicating that DRC-1339 or its primary toxic metabolite DRC-2698 (N-(3-chloro-4-methylphenyl) acetamide, CAT), a potential roost toxicant, are only moderately toxic (100-300 mg/kg) to these animals. However, there are some avian and mammalian scavengers or predators to which these compounds are considerably more toxic (i.e., cats, owls, magpies). Secondary hazards have not been observed when DRC-1339 killed starlings were fed to three raptor species for as long as 141 days and to domestic cats for seven days (DeCino, Cunningham and Schafer 1966; Holler et al. 1979, unpubl, manuscript); however, the direct long-term effects of both chemicals have not been determined on raptors or other predatory or scavenger species.