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


Date of this Version



Shivik, J.A., L. Mastro, and J.K. Young. 2014. Animal attendance at M-44 sodium cyanide ejector sites for coyotes. Wildlife Society Bulletin 38(1):217-220. doi: 10.1002/wsb.361.


Sodium cyanide (NaCN) ejectors for coyotes (Canis latrans), known as M-44s, are used in many parts of the United States for lethally removing coyotes to protect livestock or other resources. Quantifying selectivity of current devices in killing target and non-target species is important to users and provides a baseline for future development of more effective and selective techniques. We used motion-activated cameras to monitor M-44 locations for coyote and other species visitations to the sites. Because camera presence potentially influences coyote behavior, we first compared activation of M-44s at paired sites where cameras were and were not present. Coyotes activated M-44s sites with cameras (n¼17) similarly to sites without cameras (n¼19). During 832 site-days of observation, coyotes visited M-44 sites 29 times, and 18 other species visited 1,597 times. The mean visitation ratio for non-coyotes to coyotes was 2.8:1 at the M-44 locations monitored (n¼22). Non-coyotes were much less likely to touch the devices with their noses or mouths than were coyotes (0.24:1). No non-canid activated an M-44, suggesting very high selectivity toward killing canid species. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Included in

Life Sciences Commons