Frog Blog

June 2024 additions from Panama

Tatayo's Glass Frog (Hyalinobatrachium tatayoi)

Spent a couple of weeks in Panama during the summer of 2024. I went on the Canopy Family Herpetology at the Isthmus tour, which was great. Of the 37 species of anurans we encountered, I was able to record at least 24 species. Of those, at least 15 species were new to my recording lifelist including:

Panamanian Granular Toad (Rhinella centralis)
Columbian Four-eyed Frog (Pleurodema brachyops)
Striped Rocket Frog (Allobates talamancae)
Tatayo's Glass Frog (Hyalinobatrachium tatayoi)
Emerald Glass Frog (Espadarana prosoblepon)
Vicente's Poison Frog (Oophaga vicente)
Rainforest Rocket Frog (Silverstoneia flotator)
Pratt's Poison Frog (Colostethus pratti)
Spotted Foam-nest Frog (Leptodactylus insularum)
Slim-fingered Rainfrog (Craugastor crassidigitus)
Banded Robber Frog (Pristimantis taeniatus)
Panamanian Snouted Treefrog (Scinax altae)
Panama Humming Frog (Elachistocleis panamensis)
and maybe a new Tink Frog species (Diasporus sp.) - still working on identifying these!

UPDATE November 2024 - I figured out the new species - Yellow Dyer Dink Frog (Diasporus citrinobapheus)

UPDATE December 2024 - I discovered yet another new species in my recordings - Red-webbed Treefrog (Boana rufitela)!

I also added new recordings of some species I had already recorded, including:

Granular Glass Frog (Cochranella granulosa)
Rosenberg's Gladiator Frog (Boana rosenbergi)
Harlequin Treefrog (Dendropsophus ebraccatus)
Yellow Treefrog (Dendropsophus microcephalus)
Sabinal Frog (Leptodactylus melanonotus)
Mexican White-lipped Frog (Leptodactylus fragilis)
Northern Smokey Jungle Frog (Leptodactylus savagei)
Tink Frog (Diasporus diastema)
Túngara Frog (Engystomops pustulosus)

Over the next few weeks, I will be working on getting these new entries online.

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So my recording lifelist is now at 131 species, in 45 genera, and 15 families.

Family	Genus	Species recorded
Bufonidae
	Anaxyrus	9
	Incilius	3
	Rhinella	3

Hylidae
	Acris	3
	Agalychnis	1
	Boana	4
	Dendropsophus	2
	Hyla	8
	Pseudacris	6
	Osteopilus	1
	Scinax	4
	Smilisca	2
	Triprion	1

Pelodryadidae
	Litoria	9
	Nyctimystes	1
	Ranoidea	8

Microhylidae
	Austrochaperina	2
	Elaschistocleis	1
	Hypopachus	1
	Gastrophryne	2

Myobatrachidae
	Crinia	2
	Limnodynastes	1
	Platyplectrum	1
	Uperoleia	2

Craugastoridae
	Craugastor	3
	Pristimantis	2

Eleutherodactylidae
	Diasporus	2
	Eleutherodactylus	9

Centrolenidae
	Espadarana	1
	Hyalinobatrachium	4
	Cochranella	1
	Teratohyla	1

Leptodactylidae
	Leptodactylus	7
	Engystomops	1
	Pleurodema	1

Ranidae
	Lithobates	9

Dendrobatidae
	Colostethus	1
	Oophaga	2
	Silverstonia	1

Hemiphractidae
	Flectonotus	1

Aromobatidae
	Allobates	1
	Mannophryne	2

Rhinophrynidae
	Rhinophrynus	1

Scaphiopodidae
	Scaphiopus	2
	Spea	2

Banana Treefrog
Boana platanera

Boana platanera photo by Mateo Garcia Mejía
Used under Creative Commons license granted in this iNaturalist record

This recording was part of an all night recording I made at a pond at the edge of the Piedras Blancas National Park in southern Costa Rica.

Boana platanera calling from Piedras Blancas National Park, Costa Rica

After I made this recording, I was a bit confused as to the identity of this frog. I knew it didn't sound like the locally common Boana rosenbergi and I couldn't figure out what other species could sound like this. So I did some searching using online sources like xeno-canto.org, iNaturalist.org, Fonozoo.com and found the most similar call I could and found a recording of Boana crepitans which sounded similar. Of course, that species doesn't occur in Central America (it is restricted to the Atlantic Coast of Brazil). So that led me to a taxonomic hunt using Amphibian Species of the World to find what the closest relative to B. crepitans would be in Costa Rica. That led me to Boana xerophylla which eventually led me to this paper which described a new species B. platanera based on specimens from the northern part of the range of B. xerophylla.

Unfortunately, that paper described the as occurring in Trinidad and Tobago, Venezuela (north of the Orinoco River), northwestern Colombia and into Central Panama. But the species did not make it into Costa Rica. iNaturalist had this record from David in northern Panama which is only 50 miles from where my recording was made (although some have questioned that ID). So I had to dive into the paper to see if this could be the species in question.

Fortunately, the paper had descriptions of the call and waveform diagrams which matched my recording almost perfectly based their two "phases", the number of parts to the call, the timing of each part and their general description of the call.

Boana platanera calling from Piedras Blancas National Park, Costa Rica

I have subsquently listened to all the available recordings for this species on iNaturalist and they sound similar enough to confirm my identification (to me?). I can not find another species that could make a similar call that is in range.

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© Chris Harrison 2024

Escalona Sulbarán, M., E. La Marca, M. C. Castellanos-Montero, A. Fouquet, A. J. Crawford, F. J. M. Rojas-Runjaic, A. A. Giaretta, J. C. Señaris, and S. Castroviejo-Fisher. 2021. Integrative taxonomy reveals a new but common Neotropical treefrog, hidden under the name Boana xerophylla. Zootaxa 4981: 401–448 (https://doi.org/10.11646/zootaxa.4981.3.1).

Panamanian Humming Frog
Elachistocleis panamensis

The Panamanian Humming Frog (Elachistocleis panamensis) is an odd, pointy-nosed microhylid that occurs from central Panama into the lowlands of Colombia and Venezuela. It is related to our North American Narrow-mouthed Toads (Gastrophryne sp.).

range map derived from iNaturalist.org (2024)

They are generally dark with a brownish-yellow back and an irregular, dark mid-dorsal stripe. The mid-dorsal stripe is split by a thin yellow line from the tip of the pointy nose to the end of the body.

The common name "humming frog" is derived from the calls of other members of this genus in South America whose calls are reminiscent of a humming sound. But this northernmost representative of the genus has a completely different type of call. The call of the Panamanian Humming Frog is more of a high-pitched whistled trilling sound. It reminds me somewhat of the high-pitched trill of the Australian Rain Frog (Austrochaperina pluvialis)

I heard these frogs calling from a flooded grassy ditch after some heavy rains in the Tocumen marshes of Central Panama. The call of this species is fairly high pitched for a frog. Because of the high pitch of this trill, I assumed it was an insect until I got home and did some research. (The sharp "chick" calls you hear among the Humming Frog calls are part of the call of the Túngara Frog. I filtered out the descending parts of the call to bring out the Humming Frog.)

Panamanian Humming Frog call

You can see in this spectrogram how there are 12 rapid high-pitched (5 kHz) chirps in less than half a second.

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iNaturalist. https://www.inaturalist.org/ Accessed August 12, 2024

Panamanian Granular Toad
Rhinella centralis

The Panamanian Granular Toad (Rhinella centralis) is a small flat-headed toad restricted to Panama. It used to be considered the same species with the widespread South American Granular Toad (R. granulosus) but it was elevated to its own species in 2009.

Range map from iNaturalist.org (2024)

When I read about these toads and saw pictures of them, for some reason I thought they would be medium to large sized toads since many Rhinella species are very large. I was rather surprised when I found these toads along a dirt road through the Tocumen Marshes in Central Panama just how small they were.

As you would expect for a toad of this size, it's call is a high pitched trill lasting around 3-4 seconds and with a carrier frequency (dominant pitch) of around 2.5kHz. In general pitch, it reminded me of the call of the North American Red-spotted Toad (Anaxyrus punctatus), although that species has a longer trill.

Here's a couple of Panamanian Granular Toads calling next to each other in the Tocumen Marshes -

Panamanian Granular Toads calling

As so often happens when you are trying to record one species of frog, another species right next to it pipes in and makes it hard to get the recording of your target species. That's what happened in this recording. I was trying to record a Colombian Four-eyed Frog (Pleurodema brachyops - the hollow "ponk, ponk") when a couple of Panamanian Granular Toads started calling right next to them, and then a Tungara Frog (Engystomops pustulosus) added its "toy ray gun" "PEUW" song to ruin my recording.

Panamanian Granular Toad with its neighbors

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© Chris Harrison 2024

iNaturalist. Available from https://www.inaturalist.org. Accessed August 12, 2024

Narvaes, P., and M. T. Rodrigues. 2009. Taxonomic revision of Rhinella granulosa species group (Amphibia, Anura, Bufonidae), with a description of a new species. Arquivos de Zoologia. São Paulo 40: 1–73.

Colombian Four-eyed Frog
Pleurodema brachyops

The Colombian Four-eyed Frog (Pleurodema brachyops) is a small chubby "toad-like" frog found from Central Panama down into Colombia, Venezuela and across the northern part of the Guyanan Shield.

range map derived from iNaturalist.org (2024)

Although they look somewhat similar to the Spadefoots of North America, they are actually more closely related to the widespread South and Central American "White-lipped Frogs" (Leptodactylidae).

They get their common name four-eyed from from an unusual defensive behavior. When threatened, they point their broad nose down, raising their hind legs and show enlarged "eye-spots" on the rear of their torso to the prospective predator. It is assumed the eye spots contrasting with the bright red thighs attract the attention of a predator, making the predator think they are a much larger animal. Here's a photo of the posterior side of a calling frog showing the contrasting dark spots on the rear of the body.

Photo by Miguel Diaz Anaya

used under Creative Commons License granted in this iNaturalist record.

The call of the Colombian Four-eyed Frog is a nasal honking sound. The calls are made from shallow puddles in grassy areas after rains.

Colombian Four-eyed Frog calls

As I was trying to record this Four-eyed Frog calling, a couple of other species were calling next to it making it hard to isolate the target species. You can hear the honking of the four-eyed frogs along with the "ray-gun peuw" calls of the Tungara Frog (Engystomops pustulosus) and the loud trill of the Panamanian Granular Toad (Rhinella centralis).

Colombian Four-eyed Frog and friends

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© Chris Harrison 2024

iNaturalist available at https://www.inaturalist.org/. Accessed August 12, 2024.

Panama Snouted Treefrog
Scinax altae


Panama Snouted Treefrog photo by Angel Sosa-Bartuano. Used under CC-by-NC license granted on this iNaturalist record.

The Panama Snouted Tree Frog (Scinax altae) is a small, striped cone-nosed treefrog of the grasslands and marshes of the Pacific versant of Panama and into SW Costa Rica. It appears to be a southern, isolated sister population of the widespread Stauffer's Treefrog (S. staufferi) which occurs in Northwestern Costa Rica and north into Mexico.

I recorded these frogs in Central Panama just east of the Tocumen International Airport. In fact, you can hear a plane taking off in the recording!

It had rained heavily earlier that day and the frogs were calling from some flooded marshy pastureland after dark. When I first heard their buzzy call, it reminded me of a Scinax species, but I couldn't match it to any particular species I knew. It sounded like S. staufferi, but I knew that species wasn't found in Panama. I decided they must be Yellow Treefrog species (genus Dendropsophus).

It was only after I got this record uploaded to iNaturalist that another user pointed out the correct species identification. A little research online and I ended up with another new frog for the lifelist! And a new Scinax to boot - one of my favorite Neotropical hylids.

Panama Snouted Treefrog call

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Barrio-Amoros, C., Forero-Cano, A.M., Stuster, R., Batista, A., Canzoneri, M., and Arias, E. 2023. The presence of Scinax altae (Dunn, 1933) in Costa Rica, with redescription of its advertisement call. Anartia 37:34-46. https://zenodo.org/records/10516165

Spotted Foam-nest Frog
Leptodactylus insularum

Leptodactylus insularum is known by a variety of common names, including Spotted Foam-nest Frog, Caribbean Ditch Frog, and San Miguel Island Frog. I will stick with the first name since it is the one iNaturalist uses and it makes as much sense as any.

Those other names don't work in this case because they are based on location and I recorded and photographed this species neither in the Caribbean nor on San Miguel Island. So Spotted Foam-nest Frog seems a better common name (even if a bit boring). The species epithet insularum means "off the island" and derived from the first specimens documented from Saboga Island just off the coast of Panama. They are also found on a couple of Caribbean Islands (off Nicaragua) and Trinidad and Tobago, but the bulk of this species range is on mainland Central and South America.

map from iNaturalis.org

This species used to be included in the much wider ranging species, Leptodactylus bolivianus. This species group is confusing, but at the moment Leptodactylus insularum is recognized as its own species and the northern member of the L. bolivianus group.

Although they are similar in general body morph to the northern Ranid frogs, Leptodactylid frogs don't have the typical ranid snore or chuckle to their call. Instead their calls are more often like whistled popping or bubbling sounds.

The call of this species reminds me of a child "popping" their finger out of the corner of their mouth or maybe a cork popping out of a bottle. It is a bit hard to hear in this recording because there is a background of the the upward whistled calls of the Mexican White-lipped Frogs (Leptodactylus fragilis) and the constant dry trilling of the Panamanian Granular Frog (Rhinella centralis). You also hear the faint "ray gun peow" of the Tungara Frog (Engystomops pustulosus). The Spotted Foam-nest Frog calls are the lower pitched "cork out of bottle" popping that occurs every 1 to 1.5 seconds throughout this recording.

Frog chorus with Leptodactylus insularum

In truth, I could barely make these calls out when I was out in this flooded marshy area in Central Panama. The sounds of the other species were so loud I honestly pressed record and pointed my microphone in the general direction, hoping that sound was a different species I could hear in there. Only when I got home was I able to remove some of the distracting noise and hear the Foam-nest Frogs for sure.

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© Chris Harrison 2024

iNaturalist. https://www.inaturalist.org/. Accessed August 18, 2024.

Red-webbed Treefrog
Boana rufitela

The Red-webbed Treefrog (Boana rufitela). It is a "medium" sized treefrog that is normally yellowish or greenish, often with some spots or speckling in its pattern. It is highly variable in general color and pattern. It gets its name from the red webbing between the toes, although that can be hard to see on a resting frog.

This species is believed to occur from the Atlantic Slope of Costa Rica down through the lowlands of Panama (map from iNaturalist.org). However these frogs were found on the Pacific versant of Panama and there are iNaturalist records going all the way down into western lowlands of Colombia.

The Red-webbed Treefrog makes a a short "cluck" type call. It is hard to describe much else about it except that in a group, it does sound a bit like chickens clucking.

Here's a short recording of some of the little cluckers together in a reedy pond edge on the grounds of our lodge in Anton Valley, Panama.

filtered recording of Boana rufitela calling

This was another research frog for me. I had seen a few of these frogs on the reeds of a small pond on our hotel grounds. But I had not noticed them calling. I discovered I had recorded this species in December of 2024 when going back over some iNaturalist records and one of the identifiers had mentioned hearing them in my recording of the Harlequin Treefrogs (Dendropsophus ebracattus). But I had totally overlooked the rufitela calls in this recording! So I went back to my recordings from the spot and found a recording where you could hear this species calling underneath the louder calls of the Harlequin Treefrogs, among other species.

Here is what the actual recording sounds like without filtering out the louder species - Harlequin Treefrog (Dendropsophus ebraccatus), Tatayo's Glass Frog (Hyalinobatrachium tatayoi), and Sabinal Frogs (Leptodactylus melanonotus). You can just make out their clucking underneath the din.

unfiltered recording of Boana rufitela calling amongst other species

So once again, uploading calls to iNaturalist has given me a new species to my frog call recording lifelist!

Tatayo's Glass Frog
Hyalinobatrachium tatayoi

Tatayo's Glass Frog (Hyalinobatrachium tatayoi) is a small Centrolenid Frog that lives in the tropical lowland forests from southernmost Costa Rica, down through Panama and into NW Venezuela, and western Colombia and Ecuador.

range map from iNaturalist.org

The call of the Tatayo's Glass Frog is best described as a single sharp "peep" repeated every five seconds or so. When slowed down, it sounds a bit more like a "wrree", although that discrimination is difficult in a recording. Like other Hyalinobatrachium, the call is high pitched with a carrier frequency of around 4.6-4.8 kHz.

We usually found the calling, sitting upright on a broad leaf overhanging a stream, sometimes quite high over the stream. At close range the call is very piercing and I found it hard to record them because they overpowered (clipped) my microphones in spite of using 32bit float recorder. (In hindsight, I should have backed off a bit - DOH!)

The spectrogram of this call is unremarkable, showing a short, sharp percussive call at around 4.7 kHz. It has a short "arm" after the main call, but I can't hear that in the recording, even when slowed down.

Call of Tatayo's Glass Frog from Anton Valley, Panama

iNaturalist. https://www.inaturalist.org/. Accessed August 24, 2024

Yellow Dyer Tink Frog
(Diasporus citrinobapheus)

The Yellow Dyer Tink Frog (Diasporus citrinobapheus) is a small Eleutherodactyline frog found in the uplands of Panama. It gets its unusual name from its "tink-like" call as well as the fact that when handled, this species will stain your skin yellow. Here's a photo showing one of our team member's fingers after handling this frog in the photo.

The purpose of this yellow dyeing is not known, but it is postulated to have some defensive mechanism. Although the yellow skin secretion does not contain any alkaloids, it is presumed to have a bad taste which might discourage predators (Hertz, et al., 2012). There are also other species of Diastema that can dye the skin like this but this species appears to do it more than other species.

We found and heard this frog in the Anton Valley of Central Panama in June 2024. I made a recording of some other frog species at this location and wasn't sure what the higher pitched tink in my recording was. There was a prominent Common Tink Frog (Diasporus diastema) in the foreground, but the other higher tink call was a mystery. The Common Tink Frog is the louder upward slurred "tink" heard in this recording. The Yellow Dyer Tink Frog is the higher pitched "tink" heard above the Common.

Both species of Tink Frogs together

After cleaning the recording up to remove the people talking and the Diasporus diastema calls, we can hear the higher pitched "tink" more clearly. This is the Yellow Dyer Tink Frog calling.

The call of this species is a high pitched "peep" (maybe "tink"?) in the 3.3 to 3.7kHz frequency, noticeable higher and less upward slurred than D. diastema (23.5 to 29.5 kHz).

Yellow Dyer Tink Frog (Diasporus citrinobapheus) calling alone.

So once again, I scored another "research frog" to my lifelist by listening back to my recordings and finding a match!

This will make this my 130th frog species recorded!

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Hertz, A., Hauenschild, F., Lotzkat, S., & Köhler, G. (2012). A new golden frog species of the genus Diasporus (Amphibia, Eleutherodactylidae) from the Cordillera Central, western Panama. ZooKeys, (196), 23–46. https://doi.org/10.3897/zookeys.196.2774

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