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Providing evidence to improve practice

Individual study: Strobe light and siren devices for protecting fenced-pasture and range sheep from coyote predation

Published source details

Linhart S.B. (1984) Strobe light and siren devices for protecting fenced-pasture and range sheep from coyote predation. Proceedings of the Eleventh Vertebrate Pest Conference, University of California, Davis, 154-156.


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Use lights and sound to deter predation of livestock by mammals to reduce human-wildlife conflict Terrestrial Mammal Conservation

A replicated study in 1979–1983 on pasture at 20 sites in Colorado, Idaho, South Dakota, and Oregon, USA (Linhart 1984) found that strobe light and siren devices reduced predation of sheep by coyotes Canis latrans. Ten trials, using 1–2 strobe light and siren devices per pasture, provided an average 53 nights of protection (≤2 sheep losses) from coyotes. Five trials, using 3–6 devices per pasture, protected sheep for an average 91 nights. Predation rates prior to trials were not stated. During five trials on unfenced range with two siren and two strobe light devices on each site, sheep losses to coyotes were 44–95% lower than those during the previous year. Sheep on pasture were protected by units containing a commercial strobe light or a warbling siren or both. Trials occurred in 1979–1982. On rangeland, sheep were protected, from June/July to late September of 1982–1983, by two warbling-type siren units and two with strobe lights, active at night and operating at intervals of 7 or 13 minutes. Other coyote control ceased during this time.

(Summarised by Nick Littlewood)