Rio Grande Chirping Frog
Eleutherodactylus cystignathoides campi


The tiny Rio Grande Chirping Frog is native to southernmost Texas and then into Mexico.  However, they have been widely introduced into larger cities in Texas and other states.   Their chirping calls can be heard any warm night in my backyard in San Antonio, Texas.

The photo and recordings are from my backyard, although not necessarily of the same frog.


The most typical call is a short sharp chirp/cheep call.  The chirps are fast and each chirp increases in pitch.




Here's a closer view of the short call, showing how each "chirp" slides up in pitch.





These frogs also have a longer "trilled" call which they make.  It seems to me that the longer trill is the real call and the short peeps are just working up to it.




Here is the waveform and spectrograph for the first three seconds of this recording:



Here's a side by side comparison of the two types of call notes.  This comparison was created by cutting out some of the intervening notes in a long series of calls.





and here's the sonographic representation of that recording.





© Chris Harrison 2012



2 comments:

  1. I hear these in my backyard all the time here in Spring (North of Houston) Texas.

    I went out with my flashlight last night and located one by the house - it was about 10mm long and sitting in the middle of a leaf of an Elephant Ear Plant. The leaf shape was acting like a horn and seemed to be amplifying the sound.

    The ones here don't make the "trill" sound much, but often call out four "tweets" in a row, pause, then another four tweets.

    My wife's old friend used to think they were birds chirping all night long.

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    1. Congratulations on finding the little frog. They can be really tough to locate by their calls.
      Interestingly, when I lived and explored around Houston in the early 1980s, these frogs were not present. They were introduced sometime in the late 80s and have become abundant since that time.

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