Sounds like at best they're not reliable... Perhaps some deer are scared off by them and others are not is a good way to look at it. Nothing beats slowing down and being extra careful at night. I lost my step-Dad to a deer in Aug 2009 when he hit one on his '07 EGC just south of Monticello, UT. He was my motorcycle mentor and best riding buddy.

 

They DONT work...I have a "Deer Slayer" tat on my arm that proves it.

 

Now you just jinxed yourself.

 

They work great!
You just need to be sure you install them properly.
I once installed one backwards on my car...
I had a huge herd of deer chasing me down I90 for miles....

 

I have a friend that wouldnt ride a bike without one , and he lived in heavy deer country and never hit a deer, I really doubt anything is 100 % when your dealing with wild animals , and I would imagine only at lower speeds, but if they work sometimes not sure thats a bad thing either. most of the ones around here seem to notice my pipes and try to get away (hey loud pipes do save lives) and not to many stick around when I hit the air horn too. We have enough around here I think I would try anything that might help a little bit.

 

I never have either....only hit a 900 lb moose with my Silverado. Guess that's why they call them deer whistles and not moose whistles.

 

I did a little google search and found this http://www.ibmwr.org/otech/deerw.html

 

deer are stupid....they will run any direction when spooked....including right into you.....

I don't think the whistles work....besides....really don't want to spook them.

The best technique I have used is flashing the brights.....this tends to freeze the deer long enough for me to get past them.

 

Not sure what brands were tested but a few years back Consumer Reports did a story on them with real proximity testing and could find no reaction by the deer.

Quote from another forum I used to frequent:

"Read the Consumer Reports investigation into the deer alert products some time ago and the bottom line was they were ineffective, and thus, a waste of $$$. Had a biker friend killed last year here on a two lane at dusk by hitting a deer that ran out in front of him on his motorcycle. He had a deer alert device on his ride and swore by it no matter what anyone said. The device was still affixed to his bike when they hauled it away on the flatbed, covered with fur and blood."

I have a friend who is an EMT and have heard similar stories.

 

Excellent article. I think it spells it out pretty clearly that the whistles don't work. It also helped me understand something about deer behavior which now makes perfect sense:

"...the deer rutting season in the fall is the peak hazard time as deer movement is increased and they are "oblivious" to outside activities that don't relate to mating..."

So watch out for those horny deer....