Reptile & Amphibian Forums

Hi. I live in North Carolina and have spend hours researching native frogs in hopes of identifying the species that lives in our pond. The attached picture was from earlier this spring. They just seem to get bigger and bigger though. We thought originally that they were all Green frogs, Rana clamitans. Lately some look a lot more like bullfrogs. The calls at night are mixed. I know that we have some green frogs. I haven't been able to locate dorsolateral ridges on any that we can see though.

Could the bullfrogs being living in the same pond with the green frogs? They are all supposed to be territorial. Is it possible that the bullfrogs took over the pond and the green frogs are now living somewhere nearby so that we can still hear them? I'll try to get some newer pictures and write later.
Thanks,
Erin

I live in southeast Virginia and I can see where you have had problems getting a positive identification. Green frogs in particular are difficult to ID from a distance. Some of the ones that I see have a very obscure dorsolateral fold because they are so dark-colored. In some places the green frogs and the bullfrogs cohabitate nicely, they just have different microhabitats.

Pay attention to the calls, that will clue you in better since they are so distinctive.
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I'm sure both are living back there now. The 2 calls can be heard at night and early in the morning and they are very distinct. I was pretty sure that some were bullfrogs. I did get this snap shot of a frog that I think is a green frog. It looks like there is a faint dorsolateral ridge in the picture. Since the last post I had noticed some floating in the water with fairly clear ridges on the back. It seems like they get pretty close to the other species unless I'm mistaken.

That is a bullfrog.

That is a bullfrog.

Really? How can you tell. All of characteristics between green frogs and bull frogs are so similar except for the dorsolateral ridge on green frogs. This one appears to have more of one than many of the frogs in the pond. Most of the larger frogs look just smooth on the back.

I know, cause I catch both out at some ponds every once in a while, I'm really good at identifying species. Especially ones I have grown up with.

What I meant was this. Support your assertion with physical characteristics in the picture that make you believe that it's a bull frog. We do definitely have both in this pond. Identification between these 2 species is difficult for even experienced herpetologists.

Yeah, well that pic is definately a bullfrog. I have a few in my room right now and they look exactly the same except for the size, I also have a couple green frogs here right now as well.

You're still not supporting your argument.

That was the support for my ar[bleep]ument, that I have up close examples to see and compare.

Well, I'm Real convinced. (Hope you can tell that was sarcastic.) You describe no characterics or sources. It doesn't sound like you even know what a green frog is.

Look in "National Audubon Society Field Guide to North American Reptiles & Amphibians" pages 189 & 190 and yu will see the obvious difference. You can tell alone just by the body shapes.

Don't get so worked up, man. I'm a scientist looking for real scientific evidence to support a theory. All you're doing is listing your so called creditials.

I wouldn't take my students' word for it either without evidence, such as facts from credible sources such as books and web sites and articles. Even in your responses you have listed no specific observations such as the size, color, markings, etc. that lead you to this conclusion. You don't describe the physical differences between a green frog and a bull frog.

Because you imply there is such an obvious difference between the 2, I'm not sure that we are even talking about the same frog. I noticed that you listed having green tree frogs, Hyla cinerea in an earlier posting but I don't recall a mention of green frogs Rana clamitans.

By the way, I have National Adubon Field Guide. It does not have very much info about any animal. However, I have many other sources that discuss the small differences between the two and they mention the main physical characteristics that make identification difficult, the dorsolateral ridge. No, the difference is not obvious in various specimen in the field.

Mybe they are just obvious to me then, I can tell C.cornuta apart from C.cornutxC.cranwelli or ornata. That's no easy feat either. And I just got thos frogs after I posted that, there are 8 bullfrogs and 2 green frogs. I have been working so long with these animals identifying them is really easy for me. Now I admit if you have a small frog sitting in the weeds with most of it's body obscured you can't tell what it is for sure. If you need me to take pictures of the various frogs I have then I will, but it's a royal pain to do so and it stresses them out.

No, I really don't need you to take any pictures. I can get all kinds of pictures myself. If you're going to take pictures and still not discuss the physical characteristics between the two species, it'll do no good. I'll just take my sources and support my theory with them.

A field guide with 1 paragraph about each species does not give enough information for you to call yourself an expert. You still seem to think that your word that you know all this is support. I guess I'm just not so naive as to take anyone's word without that person being able to even argue a point with reference to facts about real observations.

Your credibility is gone because of your lack of professionalism. When I posted the question about what kind of frog this is, I needed to know how to tell what kind of frog it is. So far, my research in books and articles leads me to my belief. All you've done is tell me that you know, without telling how to make the judgement. I asked you how you came to this conclusion from the start. I was looking for a description of characteristics from the picture and knowledge that would lead a person to make such an observation. You've recanted each time with assertions that you have experience and you just know. An experienced herpetologist would describe what you look for in a bull frog or green frog or anything else. For all I know, you may not have any frogs because of your lack of discussion. (Not that I believe that or that I'm trying to insult you. It is your lack of discussion.)

There are hundreds of web sites about each species. Some give more information than others. On the Georgia website, they even list the bull frog as a "similar" frog to the green frog. I don't have time to go back through all of the sites and books that I've used but they all discuss the green frog as being just like the bull frog except for the dorsolateral folds along the sides of the back. The tympanum is large in both species and is larger in males than the eye in both species. Both species have a fold from eye to shoulder. There are also 2 variations of the green frog and each individual is slightly different. They don't all look like one picture. Although the picture I took is not very detailed, you can see dots coming from the fold mentioned above going down the side of the back and fading away. It is my understanding that this line is not always obvious. In referential material, the best examples of a species is usually used. You may or may not be right about this frog but until you can have an educated discussion about the characteristics as I've described, I can't take your word for it.

Although I don't claim to have a frog factory, I've got hundreds of these frogs as well as bull frogs. That was just 1 picture.

Thanks.

I don't knwo all the scientific terms for all the charachterisitics, because I don't have that kind of time to memorize them all. but that frog in the piture has no folds along it's spine like green frogs have, and colorations and patterns and shapes of the body are other big charachteristics to tell thse frogs apart. Such as the bullfrog is much stalkier than a green frog, the colors are very hard to explain, you have to have seen about 100 specimens of each to notice the color differences. As well as size differences whereas a bullfrog can get 9" the biggest green frog I have seen was 5, or 5 1/2" long. I hope that's a little better, and sorry for the lack of scientific terms I don't know them all.

looks lke a green frog....for sure not a bull frog....

Thanks. I thought so too. You can see dots that look like a ridge on the side of his back extending from the line that leads from ear to shoulder. I understand that this is why people have such a hard time identifying this frog. That ridge is hard to see on a lot of green frogs but I can make it out in this picture. Just wanted to know if anyone else could see it.