Couch's Spadefoot Toad (Scaphiopus couchii) is a widespread southwestern US representative of the family Pelobatidae. They occur from Oklahoma to the the Gulf Coast in southern Texas and then west through the desert lowlands Arizona and far eastern California. In Mexico they range through the lowlands of Sonoran Desert, Chihuahuan Deserts and Tamaulipan Biotic provinces.
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| Couch's Spadefoot (Scaphiopus couchii) Quitman Mountains, Hudspeth County, Texas |
Although they have a large range, Couch's Spadefoot Toads are not often seen. Like all Spadefoot Toads, S. couchii are explosive breeders which only come to the surface after heavy rains. Outside of those breeding events, these amphibians spend most of their lives buried in the soil with the aid of the spade-like keratinized digging structure on their back feet. This structure is the basis for their common name.
Like several other Spadefoots, the call of the Couch's Spadefoot is a loud groaning sound that emanates from their large vocal sac. The degree to which Couch's Spadefoot vocal sac inflates is quite extraordinary. It literally lifts the "toad" out of the water.
Strangely, I am somewhat allergic to the skin secretions of this species of spadefoot. When I handle these frogs too much, I begin to sneeze repeatedly until I can get away from the smell of the frog. Interestingly, I have heard other people report similar response to this species. Other species of spadefoot don't seem to have the same effect on me or other people.
These Couch's Spadefoot Toads were recorded in Wilson County, Texas after a heavy late April rainfall.
Here is the spectrogram for these frogs. You can see that the call is quite buzzy (not at one distinct frequency on the Y axis) and that it goes up in pitch, then down. There are two individuals calling here. The first one is close and the second one is further from the microphone. You can see that by the darkness of the call on the spectrogram. (This spectrogram represents the end of the recording starting at about 5 seconds in.)
The indistinct blurry band at around 5 Khz that starts just around the 1 second mark on this spectrogram here is a Great Plains Narrow-mouthed Toad (Gastrophryne olivacea). You can hear its nasal whine in the recording as well.
Here is a short video showing the extraordinary effort involved in this species call.
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© Chris Harrison 2013
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