Anaxyrus (formerly Bufo)*

Toad May 2

Early in May I found this little toad while I was mowing. After taking a few photos, I helped it into a flower bed and continued mowing, planning out a blog post as I made circuit after circuit around the yard.

I thought it would be a fun exercise to identify my toad. In the past, I’ve had good luck identifying reptiles and amphibians using the information provided on the Virginia Herpetological Society’s website, so I started there.

Have a look at this page from the website, which outlines the anatomy of a toad’s head, particularly the cranial crests, postorbital ridges, and parotid glands. The next page illustrates how these structures help identify three of the six species of toads found in Virginia.

Based on a visible (but not prominent) cranial crest, I narrowed the list of possibilities to either an Eastern American Toad or a Fowler’s Toad. But the pertinent detail for separating these two species, whether or not the postorbital ridge contacts the parotid gland, was not discernible. Falling back on secondary characteristics, I spent some time counting the number of warts in each of the toad’s spots. One or two warts per spot indicates an Eastern American Toad, while Fowler’s Toads have three or more. My toad had one or two in most of its spots, but three in a few. Since the two species are known to hybridize, was this inconsistency enough to identify my toad as a hybrid?

Two of the other listed characteristics aren’t visible in my photos. I can’t say whether my toad had spots on its chest and abdomen, nor if it had any enlarged warts on its tibia. (No enlarged warts are visible in my photos, but the photos do not show the full length of both tibias.)

Having exhausted my vague knowledge of toad anatomy, but still without a definite identification, I was curious as to whether an expert might have better luck. I sent my photos to the Virginia Herpetological Society’s e-mail identification resource, and their prompt response said my toad was likely a Fowler’s Toad. But they added a note: “Toad ID can be a bit tricky…”

Toad May 2

* In the last decade, genetic findings have shaken up the world of toad nomenclature. One of the changes removed some North American toads from the genus Bufo and shifted them into a new group with an old name, Anaxyrus. This article provides a good overview. So, for most of my Virginia toads, Bufo has been reduced to a parenthetical:  Anaxyrus (formerly Bufo). I feel a bit bereft, as Bufo was one of the few genus names I had bothered to memorize, but I suppose Anaxyrus is easy enough to remember. Except, I’m not quite certain why I would ever need to remember the genus names of North American toads…