Frog Croak Detection ???

[3v0]

I will try to provide enough info without making this too long. For the most part I want to know if I am on the right track. Anything past that is a bonus. Motivation for project is at end.

I need to hook up a PIC to detect the loud croaking sound bull frogs make. How to do detect the croaking. This audio stuff is new to me.

I am thinking that detecting the amplitude of the sound would be enough? They are quite loud.

So mic->opamp->ADC ?

Sample about 10 times a second and wait for the jump that would indicate a croak.

I have this mic on hand

Super Sensitive Electret Microphone - Small metal case microphone for audio applications has a built in FET. Use with a 15K resistor to the + lead. Ground goes to the case lead. Has small black dust cover. Overall diameter is .39". Height is .30". Has 2 PC pins for connection. G13702

Circuit suggestions ?

Motivation
Our pond is attracting bullfrogs that feed on the young fish. I need to drive them away or make them easier to catch. The first step is to detect them.

 

[Sceadwian]

Could probably stand a low pass filter to avoid triggering on higher pitched noises. Question for you though, what do you plan on doing when you detect it?

 

[3v0]

Could probably stand a low pass filter to avoid triggering on higher pitched noises. Question for you though, what do you plan on doing when you detect it?

This seems to be unexplored territory.

I was thinking of hooking up some halogen work lights that would shine bright light in the frogs eyes. Since they mostly croak at night that out to be quite unpleasant. This will be less of a problem with the neighbors then loud sound.

The hope is that it would cause new arrivals to move on.

If nothing else it might blind/stun them for long enough to catch them with a net.

The caught frogs get an all expense paid trip to a larger pond on the other end of town.

Where you thinking frog legs?

 

[ericgibbs]

hi 3v0,

Would it be possible to record the croaks, male/female attractors and replay the 'croaks' in a trapment area?

Then you could croak the croaks with a baseball bat!

 

[bryan1]

hi 3v0,



Then you could croak the croaks with a baseball bat!

Another idea, replay the recorded croak on an elevated grass platform, when in position get your favorite 3 wood out and drive the frog to the other end of town without needing your car keys



Cheers Bryan

 

[AllVol]

IOur pond is attracting bullfrogs that feed on the young fish. I need to drive them away or make them easier to catch. The first step is to detect them.

...though the boys throw stones at frogs in sport, yet the frogs do not die in sport but in earnest. - Plutarch


The very best way to absent Pyxiecephalus adspersus is to make his environment unpleasant. If possible, you could clear around the pond to eliminate the marshy, vegatative areas he prefers.

I seriously doubt p. adspersus is making much inroad into your fish population as they much prefer prey such as insects, snails and crayfish that move slowly or remain still long enough for a brief flick of the tongue. The only fish that would fit this category are those already about to "belly-up"

Personally, I rather like the "jug-o-rum" croaking on a pleasant summers evening.

 

[3v0]

...though the boys throw stones at frogs in sport, yet the frogs do not die in sport but in earnest. - Plutarch

I never said anything about killing them so do not go all mushy on me.

The very best way to absent Pyxiecephalus adspersus is to make his environment unpleasant. If possible, you could clear around the pond to eliminate the marshy, vegatative areas he prefers.

That is what I intend to do with this rig.

This is a water garden. Looks like a pond but it is actualy a large outdoor 2K gallon aquarium with dragonflies and such. Over 30 varities of hardy water lillies plus various marginals. Not about to toss the plants.

I seriously doubt p. adspersus is making much inroad into your fish population as they much prefer prey such as insects, snails and crayfish that move slowly or remain still long enough for a brief flick of the tongue. The only fish that would fit this category are those already about to "belly-up"

These are slow moving fantail goldfish with double tails. They are not nearly so swift as a single tail fish. The best looking fish are often the slowest moving (target of opportunity). If I let the frogs do the culling I will end up with a bunch of single tail goldfish. Not the desired outcome

I had an excellent goldfish spawn last year with lots of places for the fry to hide. After the goldfish fry had exceeded the size where other goldfish would eat them many of them disappeared. This was new, so were the frogs.

I am NOT 100% sure it was the frogs, I have found other accounts on the web were bullfrogs ate young bullfrogs and goldfish. One where the tadpoles sucked on the goldfish slime coat causing sores but that was a bit of a special case.

Sharon, bullfrogs will eat anything that they can catch, depending on their size...

.

 

[AllVol]

This is a water garden. Looks like a pond but it is actualy a large outdoor 2K gallon aquarium with dragonflies and such.

Oh.

Frightfully sorry. I envisioned a several acre pond coming up to the back of your house, complete with boat dock and swimming area, supplying water for the several head of cattle on your ranch.

If it's just a goldfish pond, don't be squeamish. Just grab the offending sucker by the legs and throw him over the fence.

Or something.

 

[HarveyH42]

You could encourage/introduce bullfrog predators (cats/dogs/birds). I think doing this electronically might take a while. Good start would be to record the croaking, and see if there is some average amplitude/frequency/duration you could use to single out just the frogs, for the most part.

I have to agree, don't remember anything about frogs eating fish, but I guess anything that eats bugs will eat just about anything... You might have something else eating your baby fish. Frogs eat a lot of insects, which is a good thing, unless you're an entomologist. I believe they croak to attract a mate, so might not be hugely effective. Might search some biology/zoology sights and see if you can find anything useful. Universities tend to spend a lot of tax money grants on some of the craziest research projects, maybe something has been done relating to your project.

 

[ericgibbs]

hi 3v0

Thought this might amuse you!

**broken link removed**

Regards

 

[HarveyH42]

Water garden... Yeah that makes things a little different. Obviously you don't want to do anything to disturb the plants or fish. Bright lights might not be good either. How about a barrier? Where are the frogs coming from? Perhaps you can make it more difficult for them to find or access your pond. Sounds like a real frog paradise, so it'll be a continuous battle regardless. Maybe there are some plants or ground cover that frogs don't like, that you could border your property with. Does your neighbor have a frog-pond?

 

[Pommie]

Here in Australia, cane toads are a huge problem and various ways have been found to catch them. I tried to find the winner of a competition last year for the best trap but couldn't find it. I did find this page. The best attractor seems to be light as that attracts bugs.

Mike.

 

[3v0]

Thanks everyone.

To start with I will check for amplitude and maybe toss in duration. If that does not work I can use filters to screen out most everything but the croak freq.

This PM I will put a tape recorder out by the pond and get some samples.

I have the opamp, may have the cap values in mylar. If not I will have to order them.

 

[HarveyH42]

I did a search for 'bullfrog control', and this project just got more interesting. If you come up with something that works, you are a rich man (well somebody will anyway). Seems bullfrogs are becoming a global problem, very prolific, mobile, and not many natural preditors. They'll eat anything, even other bullfrogs. Females can lay as many as 20,000 eggs at a single breeding.
One canadian website I visited (should have grabbed the link) was kind of amusing, they want to preserve their native bullfrogs, and erraticate the Americans (bullfrogs, I presume).
There doesn't seem to be any simple, or effective control. Outside their natural habitat the seem unchallenged. If they start laying eggs in your pond, you are in trouble, but should be easy to remove. The eggs will be in some sort of gelatinous mass. Not sure how big a pond you have 2kgal seems large, maybe some sort of underwater camera. Maybe a r/c submarine project with camera and frog spear...

To protect your fish, you'll need to keep the frogs from getting to the pond in the first place.

 

[jbeng]

You might be able to just use a comparator circuit (with adjustable threshold) to give you a digital "sound/no sound" signal from your mic and use the PIC to time the duration of the sound. At that point, the PIC can decide if it meets the proper criteria and is most likely a croak, or something else, thunder for instance. This might help prevent falsely triggering the 'deterrent'. Also, you can just use a digital pin and avoid a lot of the analog/DSP-type stuff. Unless, of course, you're interested in that sort of thing ...
Jeff

 

[3v0]

We only had two adults. The tadpoles were too numerous to even guess. Neither the dog or the cats were interested in them.

The pond is a temp setup that we are housing our livestock and plants in till we get around to designing and building better ones. It is about 14 by 44 feet. There is a net that keeps the koi on one side and the goldfish & water llies on the other.

 

[HarveyH42]

Bummer... Well, it takes 3-4 years for the tadpoles to start making new ones. Do some research a design your new pond to be less frog friendly. I've been to several website with similar tips, might be a good idea to keep in mind. The tadpoles will have to be caught and sorted out. I don't think you will find anything that is fish friendly, but deadly to tadpoles. Most birds and fish don't eat the tadpoles, something to do with a slime coating. Adult bullfrogs will eat them, but probably prefer the other fish. I guess it'll be easier to sort out the fish after you move the plants, just drain down the pond.

 

[3v0]

Bummer... Well, it takes 3-4 years for the tadpoles to start making new ones. Do some research a design your new pond to be less frog friendly....

In regards to lastyear. As far as I could tell all the tadpoles turned into young frogs, packed their bags and left. If these all survived and return home to mate (I am not sure they do that) we are in for an invasion in a year or two.

This year I have remove one, there is still croaking so there is at least one more.

It may be a year or three till I get around to having the final ponds dug. Lots of time to figure out how to make it better.

When we lived in the city we had to fight off the racoones. Here (small town) there are enough dogs loose that the racoones do not dare come town. Skunks are a constant.

I guess it'll be easier to sort out the fish after you move the plants, just drain down the pond.

I do that every so often to cull the single tailed goldfish. Once a year is best. Not too sure it will get done this year. The water plants are heavy and it is hard on the back.

jbeng:
Thanks for the suggestion. I do not mind working with the ADC.

So I will stick with the op amp instead of going to the comparator. If the simple plan does not work the op amp allows me to look at the actual sound without changing hardware.

 

[ericgibbs]

hi 3v0,

Do you have a copy of the audio program named 'Audacity', its freeware.

You can record via mic/line inputs and manipulate the sounds.

A couple of years ago, the constant squawking of magpies was a constant nuisance.
I downloaded some magpie distress calls and mixed them with crow sounds.

Played the mix back thru a couple of high powered speakers, under the garden trees, for a few minutes,
that did the trick, they flew in all directions.

Only had to do it once since, it works.

EDIT: If you do dwnld Audacity, get the Lame MP3 Encoder at the same site.

 

[3v0]

hi 3v0,

Do you have a copy of the audio program named 'Audacity', its freeware.

Thanks for the suggestion. I need to find a bullfrog in pain/fear clip and give it a try.

I still want to build the detector. I have wanted to get into the audio detection thing for some tiem. If I get the frog detection working I am going after termites next. I know that is done commericaly but have not seen any DIY projects for it.