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Providing evidence to improve practice

Individual study: Fladry and a movement-activated light and noise scarce device for managing predation by wolves Canis lupus, bald eagle Haliaeetus leucocephalus and bears Ursus spp., Wisconsin, USA

Published source details

Shivik J.A., Treves A. & Callahan P. (2003) Nonlethal techniques for managing predation: primary and secondary repellents. Conservation Biology, 17, 1531-1537


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, controlled study in 2002 in a captive facility in Minnesota and a replicated, controlled, before-and-after study in 2002 at six forest sites in Wisconsin, USA (Shivik et al. 2003) found that movement-activated guard (MAG) devices (emitting sound and light deterrents) reduced food consumption by carnivores. Captive wolves Canis lupus ate less of food protected with MAG devices (14% of available food consumed) than of unprotected food (84% consumed). Wild carnivores consumed less of MAG-protected deer carcasses (1.1 kg/day) than of unprotected carcasses (3.3 kg/day). At the same time in sites with no device, there was no difference in consumption between the later period (1.8 kg/day) and the earlier period (1.6 kg/day). Wolves, black bears Ursus americanus, fishers Martes pennanti and foxes Vulpes vulpes visited plots. Six groups of 1–7 captive wolves were each offered 1 kg of sled-dog chow for one hour during June or July 2002. A MAG device activated when animals were ≤2 m from the food. Four groups of 1–4 wolves were offered the same food, without deterrent. Study plots (30-m circumference) were established within territories of six wild wolf packs. A fresh deer carcass was placed in each plot. The study ran during April–June 2002 for 9–35 days (pre-treatment) and 16–29 days (treatment phase). A MAG device was used at one plot in each territory and one plot had no deterrent. Carcasses were weighed every 2–3 days and replaced as required. Camera traps at three territories identified species visiting plots.

(Summarised by Donovan Loh & Elspeth Wilman)

Deter predation of livestock by using shock/electronic dog-training collars to reduce human-wildlife conflict Terrestrial Mammal Conservation

A replicated, controlled study in 2002 of captive wolves Canis lupus in Minnesota, USA (Shivik et al. 2003) found that electronic dog-training collars did not reduce the amount of food consumed by wolves Canis lupus. Wolves fitted with dog-training collars, which activated when close to the food, consumed 43% of food offered. This was not significantly different to the 84% of food eaten by wolves where no deterrent was used. Four groups of 1–4 captive wolves were each offered 1 kg of sled-dog chow for one hour during June or July 2002. The wolves wore electronic dog-training collars, which emitted an electric shock when ≤2 m from the food. Four further groups of 1–4 wolves were offered the same food, without any deterrent.

(Summarised by Donovan Loh & Elspeth Wilman )

Use flags to reduce predation of livestock by mammals to reduce human-wildlife conflict Terrestrial Mammal Conservation

A replicated, controlled, before-and-after study in 2002 of forest at six sites in Wisconsin, USA (Shivik et al. 2003) found that installing lines of coloured flags (known as fladry) did not reduce overall deer carcass consumption by carnivores. Before installation, average consumption did not differ between carcasses assigned to treatments (flags: 2.0 kg/day; no flags: 1.6 kg/day). After flags were installed, consumption at these plots (2.5 kg/day) did not differ significantly from that at plots with no deterrent (3.3 kg/day). Wolves Canis lupus, black bears Ursus americanus, fishers Martes pennanti and foxes Vulpes vulpes visited plots. Study plots (30-m circumference) were established within territories of each of six wolf packs. A fresh deer carcass was placed in each plot. Plots were maintained for 9–35 days pre-treatment and 16–29 days during the treatment phase. The study ran during April–June 2002. Red flagging (100 × 7.5 cm) was suspended from perimeter ropes and was used at one plot in each territory and one plot had no deterrent. Carcasses were weighed every 2–3 days and replaced as required. Camera traps at three territories identified species visiting plots.

(Summarised by Donovan Loh & Elspeth Wilman )