The Coyote Lure Operative Device (CLOD) is a bait delivery device designed to deliver chemicals such as vaccines, sterilizing agents, predacides, and physiological markers to coyotes. Coyotes have activated the device in the field when it is filled with placebo baits, but measured delivery of an active ingredient has never been attempted. We developed a dose-response relationship for pentachlorobenzene (PeCB) residues in coyote serum and used the CLOD to deliver PeCB to captive coyotes. Twenty-two days post dosing, PeCB residues were detected in serum samples collected from every coyote that activated the CLOD. No residues were found in controls. We conclude that PeCB can be used as a physiological marker for identification of coyotes that activate CLODs. Using PeCB to quantify CLOD consumption met with moderate success and recommendations for future research are provided.

Lettuce is an important economic crop in California, with approximately 101,000 ha in production and a value of $1.3 billion in 2002. Bird damage to lettuce in the San Joaquin Valley, the central coast, and southern California is believed to amount to millions of dollars annually. We evaluated the effectiveness of Flight Control™ (50% anthraquinone applied at 10 L/ha) as a foliar spray for protecting emerging lettuce seedlings from depredation by horned larks. In field enclosure trials conducted near Huron, in the San Joaquin Valley of California, damage to treated lettuce seedlings was 8.5%, compared to 68% damage to untreated seedlings. In a field test, anthraquinone residues on the day of treatment averaged 570 ppm and at Day 50 after treatment were lower than the method of detection (0.063 ppm). However, horned lark numbers using test sites were too low to detect any differences in damage among treated and untreated sites. Anthraquinone offers promise for reducing bird depredations to sprouting lettuce, but additional testing should be conducted to evaluate this repellent in a large-scale field setting.