Proceedings of the Vertebrate Pest Conference

The M-44 sodium cyanide ejector is one of the most important tools used by the Animal Damage Control (ADC) program to protect livestock from coyotes. Unacceptable performance of M-44 cyanide capsules due to inadequate seals stimulated research to develop a better capsule sealant. Comparative tests of crude beeswax, Scheel SC-100 wax, and other materials revealed that capsules sealed with SC-100 were most resistant to deterioration in adverse environments. Based on these results, SC-100 wax was selected as the sealant of choice. Beginning in April 1989, all M-44 capsules made for ADC program use have been sealed with SC-100 wax. Since that date, the average number of capsules sold annually for ADC use is 15% lower than it was before 1989 even though the numbers of coyotes taken by M-44s each year has nearly doubled. The improved sealant appears to have increased the service life and effectiveness of M-44 cyanide capsules.