Did Rat Poison Kill Three Great Horned Owls in Menotomy Rocks Park?
Update: It appears that testing for poison was not carried out. The owls may have died after catching and eating rodents killed by Second-Generation Anticoagulant Rodenticides (SGARs). Other local raptors definitely have. SGARS is the poison in the black plastic boxes that are commonly placed behind restaurants, large buildings and, sometimes, private homes. The EPA explains that:
Second-generation anticoagulants were developed ... to control rodents that are resistant to first-generation anticoagulants. Second-generation anticoagulants also are more likely than first-generation anticoagulants to be able to kill after a single night's feeding. These compounds kill over a similar course of time but tend to remain in animal tissues longer than do first-generation ones. These properties mean that second-generation products pose greater risks to nontarget species that might feed on bait only once or that might feed upon animals that have eaten the bait. Due to these risks, second-generation anticoagulant rodenticides no longer are registered for use in products geared toward consumers and are registered only for the commercial pest control and structural pest control markets.