A Federal Parkway through a National Forrest near my home was a daily route for me for several years and at dark the deer were moving and seemed to take little notice of automobiles with or without the whistles. I have stopped and let more than a dozen pass in single file and flashing the lights and sounding the horn had no noticeable effect on them. Several friends have hit deer with the whistles installed. I just slowed to 45 mph through the area with 100% success.
If they do work, what about the dear next to the road? I envision hundreds of dear, their hooves held to their ears pleading, āMAKE THE WHISTLING STOP!!!ā
I blew on one of these whistles almost half of opening day deer season, and never saw a deer. I conclude they do not work.
Sadly the short answer is āno.ā
If youād like to read a longer answer that includes some of the reasons why, you (and anyone else for that matter) can do so at my blog, Next-Door Nature:
Dr. Kieran, Car Talk Wildlife Guru and Animal-Vehicle Biologist
Honking you horn works but use caution
They donāt work at allā¦I really depended on them until tonight when I went for a ride and I ended up hitting one, thank goodness it didnāt damage the radiatorā¦Just the grill, and the hoodā¦Most of all, I was really lucky that there was just minor damage and this was on an 89 olds. 98ā¦
Well like I said some years ago, Iām sure they donāt work but I put them on both cars over five years ago and havenāt hit a deer since. HID and LED lights also help. They donāt work on coons though. Perhaps they werenāt properly spaced and mounted to get the effect from the two tones. Hey, for $5 what else can I do? Those pesky creatures are everywhere, even in my back yard.
My wolf whistle got me slapped.
I think air transmits high frequency sound just fine, what high frequency sound does not do is go around corners. Also, small objects in the air will scatter it. Thatās why bats use high frequency sound. It will resolve small insects that are invisible to low frequency sound.
1 Like
I have a set of dragon whistles on my car, and Iāve never hit a dragon so they must work. 
2 Likes
All I can say is Iāve blown through one as hard as a could and never had a deer come to me;)
4 Likes