A Request! Do sonic deer deterrents work to prevent deer damage in yards?

A Master Gardener in Clackamas County, OR requested that I blog on sonic deer deterrents as a potential means to keep the often ubiquitous and unwanted garden visitor away.

A 1995 study found the Yard Gard (sic) Ultrasonic Yard Protector to be ineffective at deterring deer from feeding on apples in two yards with a history of deer damage. Control (no Yard Gard device) and treatment (Yard Gard device present and turned on) feeding stations were established at each yard. Twenty apples were placed at each feeding station. Feeding stations were restocked for the duration of the study.

Deer consumed 96% of the 380 total apples at the control stations (no Yard Gard) and 98.9% of the 380 total apples at the experimental stations (Yard Gard device present and turned on). Behavioral observations suggest that the deer were alert or nervous when the Yard Gard device was 'on', but this behavior did not translate into reduced deer damage.

The scat (poop) and tracks of several other vertebrates were found near the feeding stations. These include squirrels, crows and turkeys.

The bottom line for the home gardener: the ultrasonic deer deterrents are not likely to reduce deer damage to your garden.