Boulenger's Snouted Treefrog
Scinax boulengeri


 All the "snouted treefrogs" in the genus Scinax are known for their pronounced rostrum which is where they get their common name.   But Boulenger's Snouted Treefrog (Scinax boulengeri) wins the prize for the species I've seen so far.   It's duck bill is very strange looking.

This species of treefrog is found in lowland and premontane rainforest and rainforest edges from Nicaragua south into northwestern Ecuador.  Not only is S. boulengeri larger than the other northern Scinax species (S. staufferi and S. elaeochroa), but it also has much more tuberculate, "warty" skin.   It looks much more like the some of the South American Scinax species than it does its immediate neighbors.

The call of this species surprised me a bit.   I was expecting more of a "dry" unmusical call like we hear from S. elaeochroa and S. staufferi, but S. boulengeri instead has a louder vocalization that reminds me of some of the larger treefrog species.   (I should add that I did not see these frogs calling, but recorded these calls with an unattended recorder late at night.   I did see Scinax boulengeri at this pond earlier.)

The call of this species is described as a loud "wraak" and to my ear it has sort of a nasal hint to it (not surprising looking at the frog 😉).   In my recordings, I found that when the species was chorusing with multiple individuals, their call became a two part "rick-it" with a longer first syllable.

 Here is a recording of some Boulenger's Snouted Treefrogs calling from an articial pond at the edge of a premontane rainforest in the Gulfo Dulce region of Costa Rica in January 2023.  (The dry "wreek" trill in the background is the Harlequin Treefrog, Dendropsophus ebraccatus)

This recording is available for download from my iNaturalist record.  

When you take a look at just a short section of that recording (about 5 seconds in) you hear two frogs calling back and forth. As is the case with most anurans, when two individuals are calling sequentially they will alter the pitch of their calls slightly to be heard over the other. So you hear a sort of alternating, two syllable "rick-it, rock-it, rick-it, rock-it, rick-it" sound. In the spectrogram you can see the buzzy character (the wavy lines) and the short abrupt second syllable clearly.

I was very happy to see and record this species when in Costa Rica this year. What a great frog!

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© Chris Harrison 2023

Harlequin Treefrog
Dendropsophus ebraccatus


 The beautiful Harlequin Treefrog (Dendropsophus ebraccatus) is a small neotropical treefrog that occurs from southern Mexico down through Central America to western Colombia and Ecuador (west of the Andes).   Within its broad range, it is found in lowland and premontane rainforest and in clearings and open areas within those forests. When the forests are cut down, this species will occur in the vegetated ponds and flooded grassy areas where the forest used to be.

The frog shown above was photographed in Soberania National Park in Panama alongside a road that cut through the rainforest.   The recordings were made at an artificial pond in the rainforest of Piedras Blancas National Park in Costa Rica. 

The call of this species is best described as a one syllable, dry trilling "creek" sound that has an upward slur.

There is a short section of spectrogram below showing the trilled nature of the "creek" and the upward slur in pitch.   You can also see that one call is punctuated with a second syllable ("creek-kck")


Here's the recording of just that one short section.  You can hear the two syllable nature to of the second call.


What is most significant about this record though may be that (if I counted correctly), this represents the 100th species of frog I have recorded 🎊🎉!

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© Chris Harrison 2023

Rosenberg's Gladiator Frog
Boana rosenbergi


Rosenberg's Gladiator Frog (Boana rosenbergi) is one of the largest treefrog species in Central America.   It has a body length of 3-4 inches as an adult.   Although they are not as heavy bodied as some of the Leaf Frogs and Monkey Frogs, they are a very "long" frog.  

Although this is a rainforest species, this frog is quite adaptable and will breed in artificial ponds and similar water sources in rainforest clearings and even residential areas.   These frogs in this recording were living in the weedy margins of an artificial pond surrounded by grass on the grounds of the Esquinas Rainforest Resort in Gulfo Dulce region of Costa Rica.   These frogs called most evenings whether it rained or not.

I wish I had better photos of this species that this one photo from the road, but it was POURING rain when I came across this frog one night on the road I was walking.  I didn't have my camera with me due to the torrential rain.   I also wasn't motivated to spend time to pose it for a better "phone photo" because both my raincoat and hat had already become saturated and I was worried about my recording gear getting wet.   I know, lame excuse! 😢

Like some of the other big Boana treefrogs, the call of this species is dry and course and quite percussive.  It is a two part "tok-tok" call that reminds me quite a bit of the similarly large Australian White-lipped Treefrog (Nyctimystes infrafrenatus), even though the two species are not closely related.

If we take just a short section of that recording and look at the spectrogram, we see the individual pairs of percussive strikes. (The recording is below the image if you want to hear it).

Notice that, once again, when two frogs are chorusing together, one individual will alter the pitch of its call to avoid being masked. So we hear a distant double call, then our main "actor" gives his two "toks", followed by another frog's two "toks" then the main frog calls again.  In this case the second frog has used a lower frequency call and you can see that in the height of the bars of the second set of calls compared to the first frog's call.  They aren't quite as high because the call is lower pitched to help distinguish them from each other.

 

List Update for January 2023

Spent the holiday season of 2022/23 on a trip back to Costa Rica.  Didn't spend a lot of time recording frogs but I did get to add a few species to my recording lifelist.

Granular Glass Frog (Cochranella granulosa) - new species
Rosenberg's Gladiator Frog (Boana rosenbergi) - new species
Red-eyed Treefrog (Agalychnis callidryas) - new species 
Boulenger's Snouted Treefrog (Scinax boulengeri) - new species
Fitzinger's Robber Frog (Craugastor fitzingeri) - new species
Harlequin Treefrog (Dendropsophus ebraccatus) - new species
Túngara Frog (Engystomops pustulosus) - new species

I will be adding the species accounts and recordings for those species in the coming weeks.
 
I also found that not only did I add another species to the list, but that I had recorded it previously and skipped adding it.   That species will be added soon once I confirm my recordings

Plantation Glass Frog (Hyalinobatrachium colymbiphyllum) - new species?

So, a bit of updating to the lifelist means it looks like this....


Family Genus Number of species recorded so far
Bufonidae


Anaxyrus
10

Incilius
3

Rhinella
2



Hylidae


Acris
3

Boana
2

Dendropsophus
2

Hyla
8

Pseudacris
6

Osteopilus
1

Scinax
3

Smilisca
2

Triprion
1



Pelodryadidae

Litoria
6

Nyctimystes
1

Ranoidea
4



Microhylidae

Austrochaperina
2

Hypopachus
1

Gastrophryne
2



Myobatrachidae

Crinia
1

Limnodynastes
1

Platyplectrum
1
Craugastoridae

Craugastor
2

Pristimantis
1

Eleutherodactylidae

Diasporus
1

Eleutherodactylus
9



Centrolenidae

Hyalinobatrachium
3

Cochranella1

Leptodactylidae

Leptodactylus
6

Engystomops
1
Ranidae

Lithobates
8



Dendrobatidae

Oophaga
1



Hemiphractidae

Flectonotus
1



Aromobatidae

Mannophryne
2



Rhinophrynidae

Rhinophrynus
1



Scaphiopodidae

Scaphiopus
2

Spea
2

Total # Families = 15

Total # Genera = 36
Total # Species = 103!


© Chris Harrison 2023

Some links being fixed

 
 
 Esteemed Blog Readers,
 
I am migrating some of my recordings to a new server.   This means I have to go through and change a LOT of URLS for my recording links within my blog posts.  
I am working on it a little a time.   Sorry if some recording links aren't active now. 
 
Chris

2021 - Texas "Big Frog Year" Attempt

 Since I wasn't going to be traveling internationally thanks to SARS-CoV2, I decided the best goal for this year was to try and do a "big frog year".   Actually, I have a wager with a friend to see who can get the most bird, butterfly, amphibian and reptile species posted in iNaturalist this year.

So I thought I would make a post here and update it periodically to see how I progress.   I am getting perilously close to getting all the species, but there a few missing I probably won't get.   Some I only have photos of, but most I have recordings of as well.

August 18  - My original goal at the beginning of the year was to get 30 out of the 42 species of Anuran that occur in Texas.   On August 18th, I got my 35th species, the Mexican Spadefoot.  It did require a (long) drive out to west of Eldorado last night.   They are not found much closer to where I live and it rained heavily out there in the last few days.   This seemed like maybe my last chance for the year?

There are 7 species I am still missing.  There are a couple of species I'm not sure I can get (Houston Toad, Pickerel Frog), a couple more species I probably I will get (Fowler's Toad, Burrowing Frog) and then a three I might get if I get lucky (Pig Frog, Greenhouse Frog, Mexican White-lipped Frog).   There is also a new species in Texas, unfortunately, that I don't really have a good lead on yet, the invasive Cuban Treefrog.

Scientific Name  Common Name  First 2021 record
Pseudacris clarkii  Spotted Chorus Frog  23-Jan  Gonzales Co.
Acris blanchardi  Blanchard Cricket Frg. 27-Feb  Gonzales Co.
Hyla cinerea  Green Treefrog  27-Feb  Gonzales Co.
Litho. sphenocephalus  Southern Leopard Frg.
27-Feb  Gonzales Co.
Lithobates catesbeianus  American Bullfrog  5-Mar  Aransas Co.
Pseudacris crucifer  Spring Peeper  7-Mar  Shelby Co.
Pseudacris fouquettei  Cajun Chorus Frog  7-Mar  Shelby Co.
Craugastor augusti  Barking Frog  27-Mar  Edwards Co.
Eleuthero. marnockii  Cliff Chirping Frog  30-Mar  Bandera Co.
Lithobates berlandieri  Rio Grande Leopard
30-Mar  Bandera Co.
Gastrophryne olivacea  W. Narrowmouth Toad 2-Apr  Jackson Co.
Anaxyrus americanus  American Toad  9-Apr  Angelina Co. (photo) 
Incilius nebulifer  Coastal Plains Toad  9-Apr   Angelina Co.
Eleuthero. campi  Rio Grande Chirping
9-Apr  Angelina
Hyla chrysoscelis  Cope's Gray Treefrog  9-Apr   Angelina Co.
Hyla versicolor  Gray Treefrog  9-Apr  Angelina Co.
Lithobates clamitans  Green Frog  10-Apr  Angelina Co.
Anaxyrus woodhousii  Woodhouse's Toad  23-Apr  Denton Co. (photo)
Hyla squirella  Squirrel Treefrog  1-May  Victoria Co.
Pseudacris streckeri  Strecker's Chorus Frg.
1-May  Victoria Co.
Gastro. carolinensis  E.Narrowmouth Toad  1-May  Calhoun Co.
Lithobates areolatus  Crawfish Frog  1-May  Victoria Co.
Scaphiopus hurterii  Hurter's Spadefoot  1-May  DeWitt Co.
Anaxyrus punctatus  Red-spotted Toad  2-May  Edwards Co.
Anaxyrus speciosus  Texas Toad  2-May  Kinney Co.
Scaphiopus couchii  Couch's Spadefoot  2-May  Kinney Co.
Anaxyrus debilis  Green Toad  12-May  McMullen Co.
Rhinella horribilis Giant Toad  16-May  Cameron Co.
Smilisca baudinii  Mexican Treefrog  16-May  Cameron Co.
Hypopachus variolosus  Sheep Frog  16-May  Cameron Co.
Anaxyrus cognatus  Great Plains Toad  4-Jun  Andrews Co.
Lithobates blairi  Plains Leopard Frog  4-Jun  Andrews Co. (photo)
Hyla arenicolor  Canyon Treefrog  2-Aug  Jeff Davis Co.
Spea bombifrons  Plains Spadefoot  9-Aug  Dallam Co. (photo)
Spea multiplicata  N. Mexico Spadefoot  17-Aug  Schleicher Co.
Anaxyrus fowleri  Fowler's Toad 
hopeful
Anaxyrus houstonensis  Houston Toad 
not likely
E. planirostris  Greenhouse Frog 
maybe
Leptodactylus fragilis  White-lipped Frog 
hopeful
Lithobates grylio  Pig Frog 
missing
Lithobates palustris  Pickerel Frog 
not likely
Rhinophrynus dorsalis  Burrowing Frog 
hopeful



© Chris Harrison 2021

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.

 This species range is expanding rapidly in Texas.   When I lived on the west side of Houston in the late 1970s, I had never seen it.   By the early 1980s, it was abundant in my old neighborhood.    And the expansion is continuing through both frog movement and our increased discovery of the species.

Here's a map I made in 2015 of the known records for the species in Texas:


 In January 2021, I made a new map based on the records available from above plus new records from iNaturalist.  You can see how many of the missing counties have been filled in plus how much further north it has been documented.   It's range into the hill country is difficult to identify due to confusion with the very similar Cliff Chirping Frog which occurs there.


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.




 
* It is worth adding that in 2020, a study elevated the Rio Grande Chirping Frog (Eleutherodactylus cystignathoides campi) to species status Eleutherodactylus campi.   The original E. cystignathoides is now restricted to the coastal plains of the gulf coast of Mexico.   We will have to see if that taxonomy is accepted.   This group still needs a lot more work.
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© Chris Harrison 2012 and 2021



Ornate Burrowing Frog
Platyplectrum ornatum

One of the great things about living in the information age is how easily you can get feedback from others.   I originally identified these unseen frogs as the calls of the Striped Marsh Frog (Limnodynastes peronii) based on listening to recordings on David Stewart's wonderful frog call CD.   But in looking at range maps I started to wonder if maybe I was outside the range of L. peronii, so I posted this recording on the Facebook Australian R&A Identification group and got an answer almost immediately!   Listening to the recordings, I think I've finally got the correct ID.

The Ornate Burrowing Frog or Ornate Frog (Platyplectrum ornatum) is a stubby little frog found in a wide area the northern and eastern coasts of Australia from Central New South Wales to northernmost Western Australia.  It can apparently be found in a variety of semi-open habitats where there are sandy soils.  It spends most of its life burrowed beneath the sand only emerging during wet periods.




One night while recording frogs in a cane field area near Miallo, Queensland, I recorded this a loud frog call I didn't know.  It was a loud "knocking" sound heard over the background calls of the Australian Rocket Frogs (Litoria nasuta).   Most descriptions of this call refer to it as a metallic "unk".


Ornate Burrowing Frog Calls - Miallo, Queensland


The photo shown here was taken several years before near the town of Chillagoe, further inland from where this recording was made.

 © Chris Harrison 2014 & 2020

Eastern Central American Treefrog
Smilisca manisorum



The widespread "Mexican Treefrog" (Smilisca baudinii) is one of the best known anuran denizens of much of tropical Mexico and Central America.  It even gets up as far as the southern tip of Texas.  Even though it is widespread and very common over much of its range, it's identity as a single species is not clear.  Over the years several studies have proposed that these populations represent not a single species but a complex of multiple species.

A recent study published in the journal of MesoAmerican Herpetology has resurrected one of these species, Smilisca manisorum, that was first described in 1954 by Edward Taylor.   The population is question occurs from the eastern Caribbean lowland mesic forests from the Mosquito Coast of Honduras down through the caribbean lowlands of Costa Rica.   It is regarded as a different species from the populations on the Pacific versant of Central America.

This study separated S. manisorum from S. baudinii populations on the west coast of Central America by a series of morphological characteristics including "its consistently larger adult size, the long and flat inner metatarsal tubercle, and the increased hind limb webbing".  The paper has illustrations of these characters and the authors also collected tissues for future molecular studies.

My concern, of course, is simply did I get a new lifer!???

This Treefrog from Cano Negro, Costa Rica could fall in the area potentially inhabited by Smilisca manisorum.  Although the ranges are not completely worked out, this part of Costa Rica seems to be more affiliated with the Atlantic versant of Costa Rica than the Pacific, from which it is separated by the Guanacaste Mountains.

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Maccranie, et al. (2017) also suggest that the populations from the El Petén region of Guatemala may also represent a different species previously described as Hyla pansosana but they do not elevate that species in their publication.   That leaves me curious about the "smilisca complex" frogs I have seen in southern Campeche which is adjacent to and contiguous with that Petén habitat, but that post will have to wait until the species is elevated.

McCranie, J. R. 2017. Morphological and systematic comments on the Caribbean lowland population of Smilisca baudinii (Anura: Hylidae: Hylinae) in northeastern Honduras, with the resurrection of Hyla manisorum Taylor. Mesoamerican Herpetology 4: 513–526.

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© Chris Harrison 2020