American Toad vs. Southern Toad
Anaxyrus americanus vs. A. terrestris

When I drove to Florida recently, one of my target species to record was the Southern Toad.  I hadn't really learned the call in advance but I figured I would recognize it when I heard it since I knew most of the other species in the state.   On the way, we stopped one evening in southern Mississippi to do some herping and I heard a long trilling call.  At first I thought it was an American Toad and recorded it without thinking.  A few minutes later we found a toad on the road, but it was a Southern Toad.  That's when I realized I was too far south for American Toads...so what was that call?  I pulled up my Lang Elliott recording of US Anurans on my Ipod and listened.  It was indeed, the Southern Toad.  I had no idea they sounded like American Toads!  

Actually, there are several species of similar looking Anaxyrus species in the Southeastern US; Fowler's Toad, American Toad, and Southern Toad.

Fowler's Toad (Anaxyrus fowleri) looks similar to the American Toad (Anaxyrus americanus) but is easily separated by call.  I have dealt with those two species in a separate blog post.  Southern Toad (Anaxyrus terrestris) is easily separated from American and Fowler's Toads by the enlarged posterior extensions on its cranial crests.

Southern Toad
Florida


American Toad
Arkansas
So why a comparative post?  Because although Southern and American Toad only overlap in a small part of their ranges, as I just learned, their calls are very similar.  So how do you tell them apart?

Where they do come near each other, the American Toad is found in the mountains and Southern Toad is found in the below the fall line in the Coastal Plain.  But there are areas where both toads can be found in the same areas.  Here is an approximate range map for the two species in the Southeastern US showing the possible areas of overlap (this map is not meant to be accurate county by county, just an approximation).  Red represents the range of American Toad, yellow represents Southern Toad and the orange the possible zone of overlap.
Both species have a call that is a long high pitched trill.

Here is the American Toad (Anaxyrus americanus)


and here is the Southern Toad (Anaxyrus terrestris)

Southern Toad call


Looking at the spectra of the two calls, we see that the Southern Toad call is a noticeably higher in pitch than the American Toad.   In this example we see the American Toad with a peak frequency of around 1900 Hz while the Southern Toad is visibly (and audibly) higher with a peak of 2350 Hz.


So although these toads barely overlap in range, their calls are similar enough sounding that in the zones of overlap, it might be worth listening carefully or recording the call just to be sure.
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© Chris Harrison 2018

Latest Updates

My most recent updates include

My recording lifelist 2017 2018
May 2018 Update


It's funny how you start a "project" without really knowing it is to become a "project".   

I had always been interested in herps (reptiles and amphibians) since I was a small boy and I had always been fascinated by the sounds of the outdoors.  I did start reading about recording wildlife/natural sounds in the early 1980s, but never pursued it because recording gear was expensive and onerous to take in the field.

Then in 2010 gear had not only come down in price (and my budget had increased since my undergrad days!), but it had become more field hardy and accessible.  So I dove in and bought a microphone (Sennheiser ME66/K6 and an Olympus LS-10 recorder).  I started off recording a few birds around my house then, since I'm a herp guy, expanded naturally to try a few frog calls.

Once I got a few recordings of common species around me (Blanchard's Cricket Frogs, Gulf Coast Toads, Great Plains Narrow-mouthed Toads) and I began to get comfortable with the process of recording and editing recordings, I thought 
"I wonder if I can get all the species that occur in my area?".  After a season of this with some success, I moved on to the idea of trying to get all the species that occur in my state.

And so the project began.  As I started collecting recordings from Texas, I had to opportunity to travel outside the boundaries of the state and the country so I took my recording gear with me....and my obsession began.

So now my "goal" is to try and record as many species as I can.  Yes there are good recordings of frog calls from many developed parts of the world, but they aren't always easy to access or can be expensive to buy.   My goal was to provide a source of free recordings that people could use to help ID their frogs and toads.   And mostly, I just enjoy doing it! 😁

So here's my progress so far.  I'm actually amazed I've managed to get this much stuff posted!   



Family Genus Number of species recorded so far
Bufonidae

Anaxyrus
10

Incilius
3

Rhinella
2

Hylidae

Acris
3

Dendropsophus
1

Hyla
8

Pseudacris
6

Osteopilus
1

Scinax
2

Smilisca
2

Triprion
1
Pelodryadidae

Litoria
6

Nyctimystes
1

Ranoidea
4
Microhylidae

Austrochaperina
2

Hypopachus
1

Gastrophryne
2
Myobatrachidae

Crinia
1

Limnodynastes
2
Craugastoridae

Craugastor
1

Eleutherodactylidae

Diasporus
1

Eleutherodactylus
9
Centrolenidae

Hyalinobatrachium
1
Leptodactylidae

Leptodactylus
4
Ranidae

Lithobates
8
Dendrobatidae

Oophaga
1
Rhinophrynidae

Rhinophrynus
1
Scaphiopodidae

Scaphiopus
2

Spea
2

Total # Families = 13
Total # Genera = 29
Total # Species = 88


* Technically, I have recorded an eighth toad in this genus, the Oak Toad (A. quercicus), but I somehow deleted that recording from that trip?  I found several of the others (Hyla femoralis, Lithobates grylio, and Pseudacris ocularis) from the same night, just not those Oak Toads!  I guess another trip to Florida is in my future since I need a few more species from there as well.

** 2018 EDIT - I just got back from that Florida trip and added 6 new species and got better recordings of a seventh:
Anaxyrus quercicus (Oak Toad) - and I didn't delete them this time!
Anaxyrus terrestris (Southern Toad) 
Eleutherodactylus planirostris (Greenhouse Frog)
Pseudacris nigrita (Southern Chorus Frog)
Osteopilus septentrionalis (Cuban Treefrog)
Acris crepitans (Northern Cricket Frog) - from Mississippi
Hyla gratiosa (Barking Treefrog)

So I've got some new blog posts coming soon.

There are also some species I have recorded that are not on this list.  On a trip to Amazonian Ecuador, I recorded at least a dozen species of frogs calling but my recorder was "lost" (under some rather sketchy conditions) part way through the trip. I know I lost recordings of:
Polka-dot Treefrog (Hypsiboas punctatus)
Smoky Jungle Frog (Leptodactylus pentadactylus)
Amazon Milk Frog (Trachycephalus resinifictrix
And just for the ones I had identified before I "lost" the recorder, I had recorded many others.  Not only did I lose these species, but I had no recording device with me during our stay in the Andean cloud forests for the following week.  I probably missed 20+ species. 😡😢


There are currently over 7000 species of frogs and toads recognized in the world.  At my current rate of recording I should be approaching getting them all somewhere around my 665th birthday.   But of course, by the time I am 665 years old, many of these frogs will be extinct 😢 and so will I.

But, I guess I can just keep plodding along and see where it ends up?

© Chris Harrison 2017

Barking Treefrog
Hyla gratiosa



The Barking Treefrog (Hyla gratiosa) is one of the largest native treefrogs to the United States.  They are found in the Southeastern US from the North Carolina and along the southeastern US west to the Mississippi River.
They are typically a mixture of greens and browns with conspicuous large spots.




The Barking Treefrog gets its common name from its call which was originally compared (I guess) to the bark of a dog?  However, it is better described and a hollow "tonk" or "ponk" sound.   From a distance, a large distant chorus sounds a bit like the noise made by swinging a hollow plastic hose above their head.

Here is a chorus of Barking Treefrogs calling from a small pond near Tallahassee, Florida in May 2018.  The clicking sound heard with them is the Southern Cricket Frog (Acris gryllus).





Here's a short video clip of one calling at the same location.  At the end of the clip I have slowed it down to 10% speed so you can see how much water is displaced by the explosive nature of the call.  You can also see it in the vibrations around the frog in the photo above.



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© Chris Harrison 2018

Cuban Treefrog
Osteopilus septentrionalis




The Cuban Treefrog  (Osteopilus septentrionalis) is native to Cuba, the Cayman Islands and the Bahamas.   It is also introduced into Florida and certain islands of Hawaii.  There have been records of this species in southern Texas but they don't appear to have become established there yet.

The Cuban Treefrog is the largest species of treefrog in the state of Florida.  It is spreading northward from South Florida and has now been documented from Georgia and some other southeastern states.

Here is its documented range within Florida -



These frogs appear to spread through the transport of man made materials, potted plants, building materials etc.   They are common commensals in south Florida and are found in and around houses throughout the southern 2/3 of the state.



Unfortunately, these large treefrogs represent a significant threat where they are introduced into the US because they readily eat our smaller native treefrogs  (Green, Squirrel, Cope's Gray, Bird-voiced Treefrogs, etc).   In an effort to combat this loss of native frogs, the state of Florida is now actively encouraging Florida residents to remove any Cuban Treefrogs they find in/around their homes to prevent the loss of native species.  The following page give instructions on identification and human methods of euthanizing them - http://ufwildlife.ifas.ufl.edu/cuban_treefrog_inFL.shtml.

Cuban Treefrogs vary tremendously in appearance, not only in color but also pattern.  They can be greenish or brownish, with or without a mottled darker pattern of green or brown.  At 5 inches in length, they are almost twice the size of most of the native treefrogs.  They tend to have "wartier" skin than native treefrogs and this thicker drier skin makes them very resistant to dessication.



The call of the Cuban Treefrog is surprisingly quiet and unimpressive considering the size of the adult frogs.  It has been described as a grating "craack" or even a rattling chirp.

Here is a recording of the "craack" calls of Cuban Treefrogs near the Everglades National Park.  (You also hear the loud nasal "maaah" of the Eastern Narrow-mouthed Toad)



Here is a short video of a Cuban Treefrog calling from a flooded roadside near the Everglades National Park.  Unfortunately, the sound isn't very clear and you hear the calls of the frog in the video along with another Cuban Treefrog plus a loud chorus of Eastern Narrow-mouthed Toads and some Squirrel Treefrogs.



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© Chris Harrison 2018

Pine Woods Treefrog
Hyla femoralis

Pinewoods Treefrog (Hyla femoralis)
photographed in Leon County, Florida


The Pine Woods Treefrog (Hyla femoralis) is a common treefrog in the southeastern United States.  It is, as the name implies, usually found in or around pine forest areas.  The individual in the photo was calling from a flooded grassy pond surrounded by pine forest.

The call of the Pinewoods Treefrog is constant buzzy call alternating between two pitches.  It is often written out as "digga-digga-digga-digga" although when they are warmed up, the frogs repeat the call faster than you can speak this phrase.   This is a common call of the pinewoods areas of the southeast on warm rainy nights.

These frogs were recorded at a roadside pond in Pasco County, Florida.  This pond also had Southern Cricket Frogs (Acris gryllus), Green Treefrogs (Hyla cinerea), and Bronze Frogs (Lithobates clamitans) calling.




Here's a video of one calling that I recorded in May 2018.  It was calling from on the side of a small pine tree which is swaying in the breeze.





© Chris Harrison 2012, 2018

Greenhouse Frog
Eleutherodactylus planirostris


The Greenhouse Frog (Eleutherodactylus planirostris) is a tiny chirping frog that occurs naturally in Cuba, the Bahamas and the Cayman Islands.   However, it is better known for having been introduced into Florida and Hawaii.   From Florida it has spread north and west and is now known from the gulf coast states and has finally appeared in southeast Texas.  For those of us in Texas, it seems like only a matter of time until this species spreads across the wetter areas of the state where it will have to coexist with the very similar Rio Grande Chirping Frog.


These frogs are called Greenhouse Frogs for their habit of being found around gardens and potted plants.  However, in areas where they are introduced they can be found in almost any vegetated habitat from grassy areas to woodlands or urban yards.


Their ability to survive in such a diverse selection of habitats is attributable to both their small size and their mode of reproduction.   The adults are small enough to sit on a dime which means they can be easily transported in building materials, gardening supplies, plants, etc..  Beyond their size, they have the unusual ability to reproduce without access to standing water.  They have direct development which means the tadpole metamorphoses into a frog inside the egg so there is no need for an aquatic larval stage.  The eggs must be laid somewhere moist to prevent desiccation but do not require standing water.

Like other small "chirping frogs" in the genus Eleutherodactylus, the call of this species is a series of high pitched "chirps" or short trills.   The Greenhouse Frog is more "talkative" than other chirping frogs generally and chirps more frequently.


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© Chris Harrison 2018

Southern Chorus Frog
Pseudacris nigrita

The Southern Chorus Frog (Pseudacris nigrita) is a small striped Chorus Frog of the Southeastern United States.  It ranges from southeastern Virginia down through Florida and west along the gulf coast approximately to the Mississippi River.




I don't have photo of this species because I've never seen one.  This is particularly strange since I used to hear them calling all the time in South Carolina including in my backyard!  It was just one of those species that was "so common" I never bothered to look. 😳

Most of the "striped" chorus frogs are spring breeders so when I traveled to Florida in May of 2018, I really didn't have this species on my list of possible targets for recording.  But as we drove east of Fort Myers one rainy night I was quite surprised to hear their little "fingernail across the comb" call coming from some flooded grassy areas.   I also heard them again a few days later in the Everglades National Park.   I guess this is why you should do a little research/reading before heading out on a herping trip?

Like the other "striped" Chorus Frog species (Cajun Chorus Frog, Boreal Chorus Frog, Western Chorus Frog, etc.) the call of this species is a slow fingernail across a comb trilling.   The trill ascends slightly in pitch.



So I guess the lessons I've learned from Pseudacris nigrita are
1.  take advantage of photo opportunities when you have them
     and
2. if you don't do the research, expect the unexpected!

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© Chris Harrison 2018

Oak Toad
Anaxyrus quercicus


The Oak Toad (Anaxyrus quercicus) is the smallest species of Toad in the US with adults being slightly over an inch in length.   It is typically a brownish or reddish toad with darker spots and a bright orange or yellow mid-dorsal stripe.  It get its name from inhabiting forested areas, although it can be found in pine or deciduous forests.
 It is restricted to the southeastern US from southeastern Virginia down throughout Florida and along the gulf coast to the Mississippi River.


Befitting its diminutive stature, the call of the Oak Toad is the highest pitched of any North American Toad.  It is a high pitched peep that is reminiscent of the "peep" of newly hatched chicks.

Here is an individual Oak Toad calling from just outside of the Corkscrew Swamp Sanctuary in Florida -


Here's a spectrogram of that call showing the descending shape to their whistled peeps.  The main part of the call is between 3kHz and 5kHz but there are higher overtones visible on the spectrogram as well.



So if you are driving in a forested area in the Southeast and hear what sounds like a flock of hatched chicks calling from a flooded area, consider yourself lucky!  Stop and check out these cute little anurans.

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© Chris Harrison 2018

Southern Toad
Anaxyrus terrestris

A reddish Southern Toad from Florida
The Southern Toad is a medium-sized toad of the Southeastern United States.  It is found in the lowlands and coastal plains of southeastern Virginia, south into Florida and west to the Mississippi River.   It varies in color from yellowish to reddish to brown with darker spots.  The dark spots usually have 1-2 warts in them.


A dark Southern Toad from the Ocala National Forest in Florida 
A yellowish Southern Toad from the Ocala National Forest in Florida


The characteristic that is usually used to differentiate Southern Toads from the sympatric Fowler's and possibly American Toads is the pronounced "knob" on the posterior end of the central cranial crests (indicated by the orange arrows below).




The call of the Southern Toad is a prolonged high whistled trill lasting up to 10 seconds.



 Here is the call of a Southern Toad from Ocala National Forest in Florida.



And here's a video of that little toad making that call.




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© Chris Harrison 2018