Which Spadefoot species is this?

[Lizardman1988]

In my recent post, I observed a spadefoot toad, which I originally regarded as Spea intermontana. I'm now unsure, but I am not sure which species it could be. I just discovered that both S. multiplicata and S. bombifrons (less likely) could be in the area.

Here is the toad in question.





And a known S. intermontana from the area.



A S. bombifrons from Kansas.



I don't have an image of S. multiplicata, as it would be a lifer.

[Chris Smith]

I am leaning toward S. bombifrons... Very cool looking one at that. Hopefully someone with more experience in that part of the country will chime in.

-Chris

[bgorum]

It has a raised boss between the eyes, so it definitely not multiplicata. intermontana also has the boss between the eyes and since that is not a species I normally see I'll have to leave it to someone with more experience with those two species to help you on that one. Of course it doesn't help that spadefoots regularly hybridize, (at least multiplicata and bombifrons do).

[Jeremy Westerman]

I don't have an image of S. multiplicata, as it would be a lifer.

Or maybe you do... my personal guess I would say you have a hybrid Spea multiplicataXbombifrons because the boss looks very very weak from the photos. If I was to enter it as data though I would err to caution and say it is a S. multiplicata. Don't suppose you have any pics of the actual spade or ventral side? Different angle of the orbital region? It is hard to tell about that boss and measure against eye width from the pics. Interesting all the ones I have seen in that general area there have been S. intermontana Great Basin Spadefoot Toad

[Lizardman1988]

I didn't take anything of the spade or ventral side, since I assumed it was S. intermontana. Here is the only other picture I have that may show anything of interest.



I entered it into the database as S. intermontana, so I'll have to change it to S. multiplicata. I had not thought to look for these out here, but that's the area for you; when you get anything at all, it is either something really common, or something really weird or unexpected.

As far as i know, S. bombifrons has not been found this side of the Colorado River.

[bgorum]

I wouldn't be too quick to change that id in the data base. intermontana also has a boss between the eyes. It is said to be lower and not as bony as in bombifrons.

[occidentalis]

As far as I know, S. multiplicata is only known from San Juan County in Utah. While I'm no expert, I see no reason to think it's anything but S. intermontana. In which county was that found?

[Lizardman1988]

This was found in Garfield. According to the IUCN range maps (which are the only ones I have access to at the moment), S. multiplicata occurs in Garfield, while S. bombifrons is restricted to San Juan.

[Jeremy Westerman]

Ok let's figure this little guy out.


My dichotomous key to the genera Spea and Scaphiopus is as follows:
1a. Interorbital boss present...2
1b. No interobital boss..3

2a. Boss low, soft not bony, not extending forward of the eyes Spea intermontana Paratoid gland if visible is almost round. Glandular not bony boss.
2b.Boss high and bony, extending forward of the eyes S. bombifrons distance between the eyelids across the top of the head is shorter than the width of each eyelid. Small indistinct almost round paratoid gland.

3a. Dorsum greenish gray; spade short, about as wide as long; S. hammondi Not in Utah.
3b. Dorsum often brownish; spade longer than wide; spade short and wedge shaped, not from California or Baja California S.multiplicata (no boss) Large eyes. Distance between eyelids across the top of the head is shorter than the width of each eyelid. Paratoid gland is oval.
3c. Dorsum well patterned; spade is long and sickle shaped (not wedge shaped) Scaphiopus couchii. Not in Utah. Paratoid almost invisible. Eyes widely separated.

S. bombifrons has been recorded from San Juan, Kane and Garfield Counties
S. intermontana is found statewide
S. multiplicata is found all over the Colorado plateau in Southeastern Utah

Range-wise any of the three or a hybrid is possible in Garfield county

The eye width/interorbital thing seems to favor a S. mulitiplicata or S. bombifrons interpretation.
The boss looks very low to me in all three photos of the specimen in question and is not in front of the eyes for sure so a S. bombifrons seems very unlikely and can be eliminated.
Even the low soft boss of a intermontana is readily apparent as seen in this picture of a very young GB Spadefoot. I think most GB Spadefoots have a more apparent boss than the one in question but it cannot be eliminated with any certainty.
Spea intermontana Great Basin Spadefoot Toad and tadpole polywog

Spea intermontana young Great Basin Spadefoot Toad

NM Spadefoots have no boss at all and big eyes that are not far apart. Looks alot like the critter in question except for the slightly raised boss(?) In the first two photos of the specimen in question he has dirt between his eyes on the boss area, could this create the illusion of a hump? But the wrinkles or creases behind the supposed boss do make it seem to have height. Are we seeing things and it is a multiplicata?
Here is a Spea multiplicata New Mexico Spadefoot toad with no boss at all but dirt or a plant bit by his right eye is creating some illusion of one


After careful analysis, I can't come up with a definitive 100% identification because the diagnostic feature (Boss/no Boss) appears to me to be ambiguous in the only three photos of the animal. The best guesses I have by looking at the photos are:

1. S. intermontana by range and what I personally have found in the same area (not from comparison with my own photos and this one) is the most likely culprit however, the ones I have seen have a better pronounced obvious boss between the eyes. Lizardman1988's photo of a known intermontana looks very similar to the mystery beast.

2. S. multiplicata (with dirt on his face and confused herpers like me looking at an imaginary or very low boss) is very possible

3. or a S. multiplicataXbombifrons possible hybridization which might explain the very slight boss rather than apparent-no-questions-asked variety of obvious there-it-is-boss. Like a boss!

Go up the the photo of the mystery spadefoot put your finger over the wrinkles just behind the head and the supposed boss disappears!!!

[occidentalis]

2a. seems to fit: low boss with a almost round paratoid. Where did you get your distributional info?

[Jeremy Westerman]

I think it may be a strange colored S.intermontana with an underdeveloped boss or the angle on the photo or grunge is obscuring it. I also think that many of the features look like S.multiplicata.

colleges and museums collection location data, U.S. taxa guide, IUCN, State list of amphibians Utah DWR, U.S. Fish and Wildlife Service checklist, Fish and Wildlife species reports, U.S. department of the interior checklists, State Park Checklists, National Monument checklists, National Park Checklists, and National Park Service records, BLM records, National Forest service records data. Amphibian Species of the World, Utah Conservation data center, Biological and Conservation Database, The Nature Conservancy, Utah State University vertebrate checklist, Wildlife Diversity by region, Wildlife ecology of North America, USDI National Biological Service, Species Habitat analysis surveys

I then compare that with NAHERP data and amphibian range maps from various sources including field guides. Then it is off to the herp literature to look for any locality information.
Superimpose all that research on a Utah county map. there are some weird anomalies in the data that are probably old misidentifications however. It is also possible that range extirpations/expansions/introductions/renaming/lumping/splitting have occurred since some of the older data was collected.

Known range for S. bombifrons is San Juan County with old records in Kane and Garfield counties along Lake Powell/Glen Canyon, Escalante River and at Hole in the Rock.
Known Range for S. multiplicata is Kane, Garfield, Wayne, Emery, Grand and San Juan Counties. Much of the literature is under the name S. hammondii however.
Known range for S. intermontana is Statewide, there is collection data for just about everywhere in utah.

[occidentalis]

S. intermontana has also been considered S. hammondii in the past. My guess is that the "S. hammondii" records west of the Colorado River refer to S. intermontana, but that is speculative, of course.
Confusing but interesting group of frogs.

[Lizardman1988]

I'm swinging back around to S. intermontana on this, but I'm still somewhat unsure. Maybe intermontanaXmultiplicata? It's a shame I haven't heard any calls this year. I'm not going to call this settled until I can examine more individuals and hear calls.