High-speed deer collisions are almost a given in many areas, and they are devastating to all parties involved. Most deer hit by cars die, cars hitting deer can cause thousands of dollars in damage, people in those vehicles can be severely injured or even killed.
In the past few decades, deer whistles have become the most popular way to prevent these fatal accidents. But questions remain about whether reindeer whistles work as advertised.
It’s natural to look for ways to avoid clashes with deer and many people swear that devices like deer whistles actually work. However, all available evidence supports proven vehicle safety technologies and techniques such as defensive driving, which are more effective at avoiding deer collisions than deer whistles.
Growing problem of deer collisions
According to the Insurance Information Institute, there are about 1.5 million deer collisions every year.
The frequency of deer strikes can be traced to a number of causative factors, including habitat fragmentation, when deer are forced to cross roads to forage, and gradual acclimatization of deer from road noise over several generations.
The deer population has also recovered in recent years due to hunting restrictions and the elimination of predators such as wolves from many deer habitats. With more licensed drivers on the road every year and deer populations exploding in many areas, more deer collisions seem almost inevitable.
Deer are heavy animals with a center of gravity that is elevated by their long legs, so a blow to a deer is often disastrous for both the animal and the vehicle.
Deal Collision Vital Statistics
- Deer-vehicle collisions occur each year in the United States: 1.5 million
- Average driver and passenger deaths per year: 150
- Annual damage to vehicles: 1 billion dollars
- Deadliest month: november
- Most Dangerous State: West Virginia
- Chances of hitting a deer: every 164 racers will beat a deer every year.
According to Institute for Insurance Information the average damage to a car in a collision with deer is about $4,000. For older cars and trucks, this is enough to sum up the car.
While 166 people were killed in deer collisions in 2014 and about 30,000 more were injured, deer are still getting the worst deal. In fact, the total number of deer killed by hunters each year is only six times the number of deer killed in car accidents.
While hunters take more than six million deer into the US every year, according to American Institute of Biological Sciences drivers beat and kill more than one million deer every year.
The mechanism behind the deer whistles
The main idea behind deer whistles is that they make ultrasonic sounds that supposedly warn deer of impending danger and scare them away. Noise is usually generated by air passing through a whistle, which is often mounted on the front bumper or roof of a vehicle. Electric deer whistles are also available.

Manufacturers and proponents of deer whistles claim that deer and other animals can hear the ultrasonic frequencies generated in this way, but the sounds are too high for humans to hear. Also, they tend to claim that deer are naturally shy animals, so a loud, high pitched sound from a whistling deer will make them either stop or run away.
Currently, all evidence for deer whistling works anecdotally, meaning the people who use them are often ardent supporters of the technology. Because many people who install deer whistles do so after a catastrophic clashes with a deer, elk, or other large animal, the absence of further accidents is taken as proof that the deer is whistling, and personal experience is hard to argue with.
So do deer whistles work?
While some anecdotal evidence suggests that reindeer whistles work, and some companies even install reindeer whistles on all cars and trucks in their fleets, or insist that their drivers install them on their own vehicles, the jury is still out.
For example, if there is any real evidence that reindeer whistles work in any demonstrable way that can reduce accidents and insurance payouts, you can expect insurance companies to give a discount or even offer free reindeer whistles to policyholders. However, the opposite is true.
Most insurance companies, which often give discounts on safety technology like airbags or car alarms, discourage the use of deer whistles, and many companies like Allstate and Geico do, in fact. recommend not to use deer .
Another important question is whether reindeer whistles work as advertised.
The companies that make these devices typically say that they emit ultrasonic frequencies that repel deer, which are naturally shy animals. It seems to make sense, but it’s not really backed up by any real, non-anecdotal evidence.
In fact, some studies have shown that deer whistles, or at least the specific products that the studies have looked at, do not even generate ultrasonic sound, which is commonly mistaken for frequencies above 20 kHz, which are beyond human hearing.
Not all deer whistles claim to generate an ultrasonic sound, so such a shutdown is not necessarily a matter of truth in the advertisement. It is also important to note that different deer whistles generate different frequencies, with different intensities, depending on the design. Some of them generate sounds that deer are able to hear, so the question is whether these sounds actually prevent animals from entering the road.
However, these devices are relatively inexpensive, easy to install, and are unlikely to damage deer whistles even if they don’t work as advertised.
Evidence that deer whistling doesn’t work
While there are no studies that show deer whistles work, that doesn’t mean there haven’t been any studies on the subject. Numerous government agencies, universities, and even insurance companies have studied and tested deer whistles, and they all agree on a few points.
What most importantly available scientific data on deer whistles in overwhelmingly indicate that there is no statistically significant difference in the reaction of deer to vehicles without whistles compared to vehicles with whistles installed.
Another point raised by multiple deer whistle studies is that it isn’t clear whether deer can even hear the ultrasonic sound frequencies that deer whistles are supposed to use to scare them away. While deer can hear higher frequencies than humans, studies have shown that the range of sounds which deer hear the best fall below the frequencies generated by some deer whistles.
For instance, one study published by the Acoustical Society of America found that closed-ended deer whistles produce frequencies of about 3.3 kHz, while open-ended whistles produce frequencies of about 12 kHz that vary widely based on air pressure, both of which fall short of the 20 kHz mark commonly associated with ultrasonic sound.
While 3.3 kHz falls within the best hearing range of deer, and 12 kHz is inside the range of sound frequencies they can hear under ideal conditions, the study also found that the intensities at which deer whistles created these sounds were “totally lost” in the ambient road noise created by a typical car or truck.
Evidence of this assertion was that while the closed-ended deer whistles generated a 3.3 kHz sound, which is well within the range of human hearing, human subjects were unable to separate the noise of the whistle from general road noise.