Desmognathus ID

[JMH]

I work at a nature preserve and we record all known herp species. Today, I found a Desmognathus on our preserve and need to confirm the species. I know it is is either D. monticola or D. auriculatus, but which is it?

 

[Mark]

Given that many Desmognathus species look very similar I think it's going to be very difficult to get a firm ID from such dark photos. Did location play a part in narrowing down to those two? Why not D. conanti for example? Out of the two species you've suggested it looks more like D. auriculatus but mainly because it lacks the distinctive lichen markings of D. monticola. To add further confusion D. auriculatus hybridizes with D. conanti.

 

[JMH]

I'm pretty sure it is D. auriculatus, it doesnt have the dorsal pairs of spots found on D. monticola and D. conanti. This one has a line of light colored dots running down both sides, most often found on D. auriculatus. I also took some better pictures.

 

[Mark]

Much better photos, thanks. I think you're spot on with Desmognathus auriculatus.

 

[Vern5384]

Auriculatus is only found in the Coastal Plain, and this doesn't look like any that I've seen. If it came from the Piedmont, then it is probably conanti or possibly monticola, although I'm leaning towards the former. Locality info can really help narrow things down more. Where exactly was it found?

 

[Vern5384]

Photos of the belly would help, as well.

 

[JMH]

I work at the Autrey Mill Nature Preserve in Alpharetta, Georgia. Which I guess would fall into Piedmont. So, I will try and get a ventral picture soon.

 

[Aneides]

I'm pretty sure it is D. auriculatus, it doesnt have the dorsal pairs of spots found on D. monticola and D. conanti. This one has a line of light colored dots running down both sides, most often found on D. auriculatus. I also took some better pictures.

I agree with you on that identification.

Aneides

 

[jaster]

I don't think it can be D. auriculatus, it is too far north. Either D. monticola or D. conanti. An easy way to tell between D. monticola and the D. fuscus group are the toes. D. monticola (and the other large duskies) will have black tips while D. conanti and the others do not. A bit hard to tell from the photo, but I would lean toward D. conanti. Both species do occur in you county though.

-Brad

 

[Vern5384]

It would be an exceptional find and an incredible range extension if it were auriculatus, however, it doesn't look like auriculatus to me. Auriculatus are found in the margins of blackwater streams, sphagnum bogs, and cypress swamps in the Coastal Plain. Alpharetta is north of Atl, far into the Piedmont (actually closer to the Appalachians), very far from this range and habitat. The most parsimonious conclusion would be conanti, although monticola also can be found is this part of the state and the dorsal marking on this animal resemble monticola I have found in north GA and western NC, as does the description of the single row of white spots on the side. This is why I asked for pics of the venter. Monticola has a solid colored pale venter fairly distinctly separated from the dorsal color on the sides.

 

[Lamb]

Although the majority of transformed D. conanti that I have seen in my area (South Mississippi) have the characteristic bright dorsal spots, I do find larger, older individuals that have a bland pattern of scattered dots or flecks, like the individual in the photo I have attached. The pattern seems somewhat similar to that of your individual. A recent, helpful paper in terms of distinguishing between conanti and auriculatus is that of Graham et al. (2010):

Graham et al. 2010. Status and possible decline of the southern dusky salamander (Desmognathus auriculatus in Georgia and Alabama, USA. Herpetological Conservation and BIology 5(3):360-373.

Graham et al. mention that conanti can have small, light flecks along their sides that could be confused with the "portholes" of auriculatus. So if everyone isn't consistent in what they are calling a porthole, using that trait could lead to misidentifications. In the paper, they say that the number of costal grooves between adpressed limbs is a good character to distinguish these two species, auriculatus having 4-6, and conanti having 3 or fewer. Also, as others here have mentioned, Graham et al. emphasize that the species likely segregate or adhere to certain habitat types, conanti being more of a ravine dweller, and auriculatus more of a mucky, swamp dweller. I managed to speak with Graham about this, and he mentioned that if the water is seep fed, the populations at that water source would more likely be conanti, at least for this part of the Coastal Plain.

 

[JMH]

After doing a bit more research and reading the last posts by Lamb and Mark, I agree with it being D. conanti. On Sunday I went and got 5 more, all found within a few feet of each other. One of them looks quite different than the rest. I took some pictures of the new group, the strange individual, and ventral shots.

 

[jaster]

The large on in the second photo does remind me of D. monticola. They are bigger than the fuscus groups, and markings on its back are monticola-esque. Which ones did you take the body shots of? I know those are a pain to do, manders dont like being flipped. Maybe try using a ziploc bag in the future to pin em down and get a great shot. Both of those individuals seem to have a uniformly gray belly in my eyes. That points to D. monticola. D. conanti will have a more mottled pattern underneath. Still couldn't see the toes well.

 

[Todd Pierson]

Yeah, which individuals are the ventral shots from? The pattern and tail shape on some of those individuals is reminiscent of D. monticola, but they should have a very light, unmarked belly like this:

And here is a typical D. conanti belly.

These two salamanders can be pretty difficult to distinguish in northern Georgia.

 

[JMH]

I have been really busy with school but I finally had a chance to get some pictures last night. The pictures should be labled, D. 1A, D. 1B, D. 2A... There is one ventral and dorsal shot for each of the six salamanders.

 

[JMH]

I could only put up 8 pictures, so here are the last two salamanders.

 

[Vern5384]

Definitely monticola.

 

[FrogEyes]

It's worth noting that several well-known "species" are species complexes [eg. D.ocoee, D.auriculatus, D.quadramaculatus, D.marmoratus, possibly D.conanti, possibly D.fuscus], and there are nearly twice as many species known as are named. In many cases, that means that even a "solid" ID only has a 50% chance of being right. Locality and a small stack of scientific papers is about the only way to get something bordering on reliable.

 

[Todd Pierson]

Yeah, I'd go with D. monticola. There's certainly something weird going on with that species, though.

 

[JMH]

Is it possible to accurately sex this species? I have not come across any literature describing a sure characteristic discrepancy.