While white-tailed deer are fully able to eat and survive off of naturally occurring vegetation, crops and landscaping are more of a draw. This has led farmers, home owners, and others to come up with creative solutions in the hope that the problem of deer damage will lessen. One interesting but ineffective solution that was developed are the use of sonic and ultrasonic repellents.
There are lots of theories on which sounds will work and what is actually the reason they repel. The thought is that the mechanisms of action are because of anywhere from sounding like distress calls of other members of the herd to causing disorientation.
“Sounds are alleged to repel animals by several mechanisms: pain; fear; communication ‘jamming’; disorientation; audiogenic seizure; internal thermal effects; alarm or distress mimics; and ultrasound. After time, most animals adjust and ignore a new sound, a process called habituation.”Bomford, M. and O’Brien, P. H. (1990). Sonic Deterrents In Animal Damage Control: A Review Of Device Tests And Effectiveness. Wild. Soc. Bull. 18: 411.
Home owners will go as far as leaving radios in their gardens playing talk radio or white noise as a result of trying to protect their plants. In addition, sonic deterrents are typically in the form of pyrotechnics or other loud noises. This can be anything from gun shots to propane exploders. However, there is no scientific backing on noises deterring deer more than for a few weeks until it is no longer new to them. With this in mind, in the 1975 Great Plains Wildlife Damage Control Workshop, who describes that not even controlled explosions will deter deer after the initial shock wears off.
“Noise devices such shell crackers and propane exploders have generally proven to be of little value in controlling deer damage. The effect of such devices at the onset is positive, but after a short duration the animals become accustomed to the noise and tend to ignore it.”Loomis, F. D. and Ogden, R., (1975). Control of White-tailed Deer in Field and Orchard. Great Plains Wildlife Damage Control Workshop Proceedings. 197.
Besides sonic there is ultrasonic, but it is no more effective on deer. Emitting a high pitched noise that is inaudible to humans, ultrasonic deterrents are believed to be within the hearing range of a lot of animals.
“There is little data that mammals are repelled by ultrasonic devices. In fact, there is almost no evidence that any animal (vertebrate or invertebrate) avoids ultrasonic cues for more than short periods of time”Mason, J. R. (1998). Mammal repellents: options and considerations for development. Proceedings of the Vertebrate Pest Conference, 18.
Why It Doesn’t Work
Deer will put up with almost any deterrent if the situation is right. For instance, if they lack food in the area due to bad weather or if there is just an overpopulation of them in the area, deer will enter repellent-laden areas no matter what.
“Reproductive and social behavior, density of the deer population, and availability of food may have influenced the variability in repellency…”Seamans, T. W., (2001). A Review Of Deer Control Devices Intended For Use On Airports. 2001 Bird Strike Committee-USA/Canada, Third Joint Annual Meeting.
This is why you need to have an approach that uses rotating methods throughout the year in order to keep deer guessing. The goal is to make your property less desirable than other surrounding areas. In other words, they will take the path of least resistance; chiefly, just make sure that it is not your yard that meets that specification. Use of sound based deterrents is not out of the picture, but only use in conjunction with physical barriers and commercial sent based sprays.