Anaxyrus Americanus?

Dedicated exclusively to field herping.

Moderator: Scott Waters

Post Reply
MCHerper
Posts: 443
Joined: September 22nd, 2012, 5:13 pm

Anaxyrus Americanus?

Post by MCHerper » June 19th, 2014, 4:56 pm

Hi folks,

I found this specimen and wanted to ask if it was A. americanus or A. fowleri?

Image

Image

Thanks for your help!

User avatar
Mike VanValen
Posts: 2074
Joined: June 7th, 2010, 3:41 pm
Location: Connecticut
Contact:

Re: Anaxyrus Americanus?

Post by Mike VanValen » June 19th, 2014, 7:24 pm

I love this game :?

It looks like a fowleri to me. Did you leave location out on purpose?

MCHerper
Posts: 443
Joined: September 22nd, 2012, 5:13 pm

Re: Anaxyrus Americanus?

Post by MCHerper » June 20th, 2014, 5:56 am

Hi Mike,

Not a game, I honestly don't know what kind of toad it is, and I didn't leave the location out on purpose. It was found in Mercer County, NJ.

Thanks for your help!

User avatar
spinifer
Posts: 2388
Joined: June 7th, 2010, 9:48 am
Location: Delmarva

Re: Anaxyrus Americanus?

Post by spinifer » June 20th, 2014, 2:41 pm

I also would say fowlers.

MCHerper
Posts: 443
Joined: September 22nd, 2012, 5:13 pm

Re: Anaxyrus Americanus?

Post by MCHerper » June 21st, 2014, 5:34 pm

Thanks Spinifer!

User avatar
ZantiMissKnit
Posts: 1037
Joined: September 14th, 2012, 8:43 am
Location: Boston area, MA

Re: Anaxyrus Americanus?

Post by ZantiMissKnit » July 3rd, 2014, 7:51 am

I keep this handy, because I have a hard time telling the difference as well!

http://www.tn.gov/twra/tamp/images/glans.jpg

This, as well: http://2.bp.blogspot.com/-JikVrV-WbSM/T ... Toad12.jpg

MCHerper
Posts: 443
Joined: September 22nd, 2012, 5:13 pm

Re: Anaxyrus Americanus?

Post by MCHerper » July 4th, 2014, 6:29 pm

Hi Andrea,

Thanks for those links. Now I am really confused-doesn't this specimen have one or two warts per spot? This is why I defer these questions to the experts!

User avatar
spinifer
Posts: 2388
Joined: June 7th, 2010, 9:48 am
Location: Delmarva

Re: Anaxyrus Americanus?

Post by spinifer » July 5th, 2014, 6:44 am

The 1-2 warts per spot is a "rule of thumb" that describes most individuals, some individuals dont follow the rule.

There are several characteristics that can be used to distinguish fowlers vs american, but you have to be careful because among the variation within each species there is a little bit of overlap of theses characteristics. This individual falls into this overlap zone, so I cannot 100% rule out american, but most of the characteristics are on the fowlers side of the spectrum.

I say fowlers based on the following:

dorsal spots - most are small containing 2 or fewer warts, although 1 or 2 have 3 warts. This description could fit either fowlers or american, so not helpful with ID.

warts - dorsally warts are small and not significantly raised, around the sides of the throat and on the hind legs warts are not particularly spiny. This suggests fowlers.

paratoid - appears to be pressed against cranial crest as opposed to clearly separated or connected with a spur. Lateral edge is convex, not concave. This suggests fowlers.

ventral coloration - not pictured. Typically I would look to see if the venter was mottled with black spots (american) or immaculate or with a central breast spot (fowlers).

User avatar
Mike VanValen
Posts: 2074
Joined: June 7th, 2010, 3:41 pm
Location: Connecticut
Contact:

Re: Anaxyrus Americanus?

Post by Mike VanValen » July 5th, 2014, 6:20 pm

I echo what spinifer is saying, except for the concave/convex paratoid (learn something new everyday).

Throw in the fact that fowleri and americanus sometimes hybridize, and you often have to use your best judgement. They just sometimes don't fit into the perfect field guide description.

User avatar
ZantiMissKnit
Posts: 1037
Joined: September 14th, 2012, 8:43 am
Location: Boston area, MA

Re: Anaxyrus Americanus?

Post by ZantiMissKnit » July 14th, 2014, 8:34 am

I often use what I have found in that particular location historically as a determining factor as well. We have areas that are most- or all-Fowler's, and others that are 100% American. I know that is an inexact science, but still do it. I'll scrutinize some that I have doubts about, and the ones I'm completely unsure of I don't put in the database.

Post Reply