Hi Oliver, my opinion is that animals adapt their reactions to sounds based on what happens when they hear certain sounds. Some sounds for evolutionary reasons solicit stronger reactions (raptor vs other bird etc) other less strong (the noise of a car is not a disturbance for many animals despite the considerable energy), but the adaptive aspect greatly complicates the evaluation of the reactions to certain sounds in certain species. In contexts where it is possible to shoot from the car to wild boar the animals are very suspicious when approaching a car, the opposite reaction in protected areas (observed).

In many cases, hearing frequency range is much more extended than the vocalization range. This is an evolutionary adaptation to detect the sounds of predators and preys, but also to perceive the noises they unvolontary produce. Some ultrasonic repellers are effective (observed) probably because hearing extension to ultrasounds, unexpected in some big mammals, is functional to hear the wideband transient noises made by predators while moving, e.g. stepping on dry leaves/soil and/or breaking branches of vegetation.

In other cases, as noted by Marco, animals learn to associate a specific noise to a threat depending on their local context and experience.

Hi Olli,

I think that reactions of animals have to be always seen in biological context. Like in your examples - if the wild boar is feeding at the time a car paces by it may not react at all, while if it is in other biological context it may react heavily. This can be seen in many mammal and some bird species.

The efficiency of a harrassment device furthermore depends on:

1. Tonality

2. Frequency Spectrum and Frequency change over time (porpoise pingers use frequency sweeps)

3. Habituation - animals will learn that a potentially harrassing sound is associated with something potentially good...over time with sufficient chances to detect for instance food - that will change the reaction to the same signal in same biological context

4. Simplicity - the simpler the signal, usually the better it works - but that is pure intuition.

5. Species

6. Hearing abilities

Hope that helps,

Michal

Hi Oliver! Interesting questions. Thank you for bringing it up. The first example that comes to my mind is the case of African elephants that are deterred by African honey bees.

http://elephantsandbees.com/

I am aware that they are trying to replicate the same in Asia. But according to my searches I did not find any positive results.

This will sound like a joke but it is not. We live in a rural area that is plagued by skunks (Mephitis mephitis). A few years ago, a particularly large and imperturbable member of the species took up residence in the carpentry shop. My husband, a not particularly large but equally imperturbable specimen of humanity, cranked up Metallica on the shop stereo and left the building. The skunk departed about twenty minutes later.

(I've long maintained that heavy metal can sterilize rats at fifty yards. While I have no scientific proof of the music-sterilization connection, I should mention that while skunks still plague our neighborhood, we have not seen any on our lot since the Metallica incident.)

The gentleman mentioned above is a professional musician who has spent a fair amount of time in the back country playing on a drum and watching deer approach in response to a sound they've probably never heard before. If you are interested in variations in sound and response, I can ask him to elucidate. These are wild deer in isolated areas of Wyoming and not deer that regularly come in contact with civilization.

Thank you all for your replies!

I think especially the "genetically fixed" sounds (predators or warning calls - like jay , go-away-birds...) are quite good.

I do not really think Metallica will threat many animals (especially not im my surrounding ;-) They might get used to...

Thanks again!

You could try Muzak...

Hi Olli,

I think especially the "genetically fixed sounds" can be tricky - so for instance a visual and acoustic display of orca to scare sea lions failed heavily (although this is more of a joke itself):

https://www.smithsonianmag.com/smart-news/oregon-town-tried-and-failed-scare-sea-lions-fake-orca-180955510/

you can also have a look here for a funny story on great white sharks and orca sounds:

https://www.youtube.com/watch?v=M8kryx7or_I

And there are a couple of things that you need to consider when you try biological meaningful sounds:

1. If you produce those sounds very often non naive animals may get used to the sound. That happens for instance with the so called 'dinner bell effect' in seals getting used to porpoise repellents

2. If you use the sound of the species itself and produce it very often, then the species must adapt as well, since their own signal has been altered and may not be useful for its initial purpose.

3. If you use too many signal (probably Metallica-esk ) then the animals will get confused.

4. Motivation: What is it that acutally drives the animals behaviour during the time that you want to scare them away...?

M

Hi Michael,

very good points, thank you!

see you!

Olli

Hi Olli ;-)

I would like to add that wolves - and i am sure this this is the case for other mammals too - are capable to adjust to noices. This is the reason why livestock protection measures in the form of acoustic devices were provent to be effective only temporary (because they do not harm the animal). Another example are wolves on military training grounds. The military sounds seem to leave them cold. Probably because they are part of their environment and they do not link those sounds to danger or pain.

" Probably because they are part of their environment and they do not link those sounds to danger or pain." This is the crux of the matter. When unfamiliar sounds persist without physical repercussion, animals become inured to them. There exists technology that is supposed to scare deer away from car collisions via an ultrasonic whistle attached to cars. Doesn't appear to work. If you're interested, there is a review on Livewire that also has links to more scientific references. https://www.lifewire.com/do-car-deer-whistles-work-4061222.

Dear India,

these deer whistles do noit work!

Ultrasonic sounds are not appropriate for scaring ungulates!

But thanks for the link, maybe this will add mor information to our review!

Best