Black-bellied Slender Salamander (Batrachoseps nigriventris)

Created: February 1st, 2009 - 11:16 PM
Last Modified: November 30th, 2009 - 11:19 AM Entered by: Jonathan Hakim
Record 21900

Comments

It is a common error to assume major in grassy field habitat. I find plenty of nigriventris in grass y field habitat.

I agree that that habitat could have both species. I have found blackbellys on north facing slopes covered in oak all the way to the bottom of the slope where the gardens are as well but once I went out into the flat and grassy areas the gardens seem to take over. and I have found a couple areas where I have flipped both species under same cover in chino hills and also nearby spots. to me some of these appear to be garden just because of how robust the tail and body are but I can say I have seen some larger looking blackbellys in good habitat so I guess without a belly shot its hard to say for sure.
http://www.naherp.com/viewrecord.php?r_id=142996 this is from northern chino hills @ base of north facing oak covered hill

If you want another fun problem, take a look at these shots from the santa ana mountains down near the SD County border.

http://www.naherp.com/viewrecord.php?r_id=106383
http://www.naherp.com/viewrecord.php?r_id=106381
http://www.naherp.com/viewrecord.php?r_id=106377

Or you can look at any of my "blackbelly" photos from the Palos Verdes Peninsula. Based on habitat, appearance, range isolation, and the fact that the region is missing from every B. nigriventris and B. major genetic study I've seen, I'm convinced that at least something from the PV Peninsula is going to be split off as a new species someday.

I don't have any strictly belly shots, though some of those pictures show belly coloration from the side, including the ventral surface of the tail. I remember that the ventral coloration appeared uniformly dark all the way through the tail. The gestalt had said "blackbelly" to me right away. It was early in my slender salamander-finding life, but I had recorded 17 garden slenders and 34 blackbelly slenders over the previous year (and around 100 other slenders of 4 more species), so I was getting decently familiar with their gestalt.

Even though, at the time the combination of robust size and blackbelly-like coloration was unusual for me, and I asked for a second opinion on the ID before I entered it. This herper, who has seen 10x as many slenders as me, also felt confident that they were Blackbelly. I've seen simple double-agreement go wrong many times before though.

As far as the other ID characteristics, I'm pretty sure that dorsal coloration in this case is useless, and the robust size is common in blackbellys from favorable habitat (which can't be compared at all to blackbellys from drier or higher-elevation spots). If you have any other information or opinion, though, let me know. I work hard to get these right, which is why I'm writing so much on what I know of the entry, and I'd like to get a third opinion. Slenders are hard.

p.s. - I labeled the habitat "grassy field", but could have clarified that is was a small grassy field nestled well into a canyon system in the Chino Hills. In my experience that could represent either species.

For comparison, here is a shot of some B. major that I had found less than a week before the above entry in similar habitat. At the time the gestalt of these shouted "obvious B. major" immediately, and the change in ventral color at the tail can be seen even from the side.

http://www.naherp.com/photo.php?v_id=20148

you have any belly shots of these ? seem more like B. major based on visuals and grassy field habitat