Chlorohyla xanthomera, formerly of the genera Litoria and Ranoidea
In 2025, a new phylogeny and taxonomic structure was published for the Australian Treefrogs. This new arrangement split what were a few genera up into 30+ genera. The net effect for me was I "lost" two genera and gained ten new ones. This means a lot of my frog blog entries are using outdated taxonomy.
Getting this up to date is going to take some time, so I thought I would make myself a new lifelist, more as a "to do" list as anything else.
So my recording lifelist is now at 142 species, in 56 genera, and 15 families.
From the lowlands of tropical Mexico down into most of tropical South America, there is a large genus of small treefrogs in the genus Dendropsophus. While some members of this genus are boldly marked with white patterns, the Central American species are generally small yellow treefrogs with some brown pattern of blotches or reticulations. They can look superficially similar.
The three species in Central America are:
Dendropsophus ebraccatus (Hourglass Treefrog)
Dendropsophus microcephalus (Yellow Treefrog)
Dendropsophus phlebodes (San Carlos Treefrog)
Not only do these species look a bit similar, but their calls can be reminiscent of each other as well. The Hourglass Treefrog (D. ebraccatus) is the easiest to distinguish. Not only is its small yellow body boldly marked with large "hourglass" shaped brown blotches, but its call is also slightly different than its congeners. The call of D. ebraccatus is a coarse, loud "creek" or "creek-it" It is more course than the other two species and tends to be a single, or at most, a double note..
The Yellow Treefrog (aka Small Yellow Treefrog - Dendropsophus microcephalus) lacks the bold blotches of D. ebraccatus and is mostly a yellow frog with some brown speckling or net-like reticulations on its back. This is a frog of forest clearings, marshes and grasslands. The call of D. microcephalus is also described as a "creek", but the call has multiple parts strung together as a "creek-cree-cree-creek". It has a slightly higher pitch/frequency than D. ebraccatus as well.
Here is a recording of Dendropsophus ebraccatus and D. microcephalus calling together. You can hear how the D. microcephalus calls are higher in frequency (pitch) and have a series of repeats after each call. The ray gun "p-tew" calls are the Tungara Frog (Engystomps pustulosus).
The problem species for me are the two less marked species, D. microcephalus and D. phlebodes. In the northern parts of the range in tropical Mexico and northern Central America, you only find D. microcephalus. However in Costa Rica and south , you can find both species. In Costa Rica, D. microcephalus tends to be found on the Pacific side and D. phlebodes on the Atlantic side, but in Panama and further south, the species appear to be sympatric.
By appearance, Dendropsophus phlebodes can apparently be distinguished by having a pair of parallel brown stripes on the upper back and neck. Dendropsophus microcephalus generally lacks those stripes. While D. phlebodes is a frog of tropical forest ponds and D. microcephalus is a coastal/marshy grassland species, both species can occur in grassy, disturbed areas. They are believed to be closely related, much more closely related than either species is to D. ebraccatus (Orrico, et al 2020).
And normally on my page, this is where I would tell you the way to tell them apart is to compare their calls. But to my ear, the calls sound very similar. Both species make a "creek-creek-crk-crk-crk" type call with a strong started "creek" followed by a fading series of shorter notes.
Can you hear a clear difference between them? D. microcephalus calls seem to be a bit higher in frequency, but the rhythm seems to be the same. I have a tough time telling them apart.
Here's a short recording comparing the latter part of the call of these species (the "crk-crk-crk" parts). First you hear three "crks" by D. phlebodes followed by three from D. microcephalus..
Looking at the spectrograms of those two recordings, the carrier frequency for D. phlebodes seems to be around 5300-5500 Hz while that for D. microcephalus seems to be around 3600-3700 Hz. Is that consistent? I don't know, but it looks like I will need to dive deeper. And could you "hear" that difference on a rainy night next to a pond in a mosquito infested flooded pasture? I really don't know. Hopefully I'll get some chances to get some more recordings of both species.
Victor G.D. Orrico, Taran Grant, Julian Faivovich, Mauricio Rivera-Correa, Marco A. Rada, Mariana L. Lyra, Carla S. Cassini, Paula H. Valdujo, Walter E. Schargel, Denis J. Machado, Ward C. Wheeler, Cesar Barrio-Amorós, Daniel Loebmann, Jiří Moravec, Juliana Zina, Mirco Solé, Marcelo J. Sturaro, Pedro L.V. Peloso, Pablo Suarez, Célio F.B. Haddad The phylogeny of Dendropsophini (Anura: Hylidae: Hylinae) https://doi.org/10.1111/cla.12429
Ghost Glass Frog (Sachatamia ilex) near Siquirres, Costa Rica
I spent 7 days in Costa Rica this August. Unlike previous trips to CR, this was a frog recording trip. My previous trips have all been birding trips where I got a chance to do a few minutes or recording along the way. This trip was planned as a frog recording trip with a bit of butterfly watching/photography in the intervening waking hours.
So for that reason, I recorded quite a few species of frogs (~22) including the following new ones (I will provide links to the new blog pages as I make them):
I also heard another species calling, but missed out recording because my recorder seems to have glitched? I have several recordings from that location, but 3 of them have no sound. 😭It was undoubtedly user error, but if I can salvage something I will be able to add a recording of
Gliding Leaf Frog (Agalychnis spurrelli)
Of course, I ran across some old friends as well and was happy to record these species again!
So my recording lifelist is now at 142 species, in 48 genera, and 15 families.
Family
Genus
Species recorded
Bufonidae
Anaxyrus
9
Incilius
3
Rhinella
3
Hylidae
Acris
3
Agalychnis
4 (maybe 5)
Boana
4
Dendropsophus
3
Hyla
8
Pseudacris
6
Osteopilus
1
Scinax
4
Smilisca
3
Tlalocohyla
1
Trachycephalus
1
Triprion
1
Pelodryadidae*
Litoria
10
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
Sachatamia
2
Teratohyla
2
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
* - I am aware of the massive 2025 revision of the Australian Pelodryadid frogs. There are a lot of new genera and reassignments of species. I will probably slowly have to incorporate these changes into my blog slowly when I get the time. It will involve a lot of name changes! I guess the good news it I get a bunch of new genera on my lifelist?
Blue-sided Leaf Frog (Agalychnis annae) San Jose, Costa Rica
The Blue-sided Leaf Frog (Agalychnis annae) was the last new species I recorded in Costa Rica. That's because I recorded it in the grounds of the hotel we were staying at in San Jose the night before we flew home. The embarrassing thing was that the beautiful grounds of our hotel (Hotel Bougainvillia) had a couple of small ponds and one of the ponds had a sign talking about the "Golden-eyed Treefrog". I figured it was a translation problem and they really were talking about the common and widespread Red-eyed Treefrog (A. callidryas).
On our last day in San Jose, as we walked around the grounds taking photos, I looked at the sign again and realized they were talking about a different species altogether, Agalychnis annae! As we ate dinner I looked over my Costa Rican amphibian book and was shocked to discover that not only was A. annae a different species than I had originally thought, but it was almost extinct across much of its range and there were a few remnant pockets of this species found in gardens and parks in the sprawling, polluted, overcrowded metropolis of San Jose!
So my plans for that evening were originally just to get photos of the Peralta Frogs (Lithobates taylori) that lived in these garden pools, but now I had a new and much more exciting target....if only they would call!
Turns out they did call that night even though it hadn't rained that day. We were able to find a number of these big green frogs hiding amongst the rushes and reeds surrounding the ponds. They were quite shy, preferring to cling to the stems of the reeds/rushes rather than sitting up openly on top of leaves like the other Agalychnis species I had encountered.
The call of this frog is best described as a quiet "croak" or "puck" sound. They were only calling very intermittently as heard in this recording. This frog only calls four times in the two minutes of this recording. It calls at 4 seconds, 25 seconds, 66 seconds and 104 seconds in. It takes a fair bit of patience to capture anything at all. I assume they would call more aggressively during rains?
Here's another recording made of a different individual where the calls are a bit more frequent.
The Dwarf Glass Frog (Teratohyla spinosa), as the name implies, is a small Centrolenid frog found in lowlands and tropical foothills on the Atlantic versant of Costa Rica and Panama, then into eastern Panama and the foothills of western Colombia and Ecuador. There is apparently a disjunct population in eastern Honduras and there are recent records from Nicaragua.. The curious gaps in range in most of Nicaragua and central Panama may represent under-sampling or may be the indication of the disappearance of intervening populations? This is one of the species that appears to be increasing in numbers again after a population decline in the last few decades associated with chytrid infections.
We found more than a dozen of this small frog calling from leaves along a rocky stream at the Costa Rican Amphibian Research Center. Some were calling many meters away from the edge of the stream. The individual in the photo above was photographed and recorded calling from the leaf it is sitting on, a meter or so above the ground and around 5 meters away from the stream.
The call of this species is best described as a high-pitched, buzzy "creek-creek-creek" with a carrier (dominant) frequency around 5.5 to 7 kHz. In the recordings I was able to capture, the call was a series of five creek sounds that descended in pitch towards the end. I also noticed that the fourth creek was shorter than the others, almost a sort of grace note. So the call could be transliterated as "creek-creek-creek-cre-creek".
Here is a spectogram of one of that series of calls. You can see the "trilled" nature of the creeks, the shorter fourth creek, and how the frequency of the calls decreases at the end.
Certainly one of the most striking frogs I was able to record in Costa Rica this year was the Ghost Glass Frog (Sachatamia ilex). These amazing frogs are almost other-worldly in appearance. Their slender green bodies, delicate limbs and amazing big white eyes with their "scribbled" iris pattern make this one of the most sought after target species to visitors in its range.
This beautiful species occurs in the foothills of the Atlantic versant of Costa Rica then south into the Darién region of Panama and into the northwestern part of Colombia. This is a frog of rocky streams in the steep rainforest valleys. They are usually found on leaves or stems at night along those rocky streams.
Interestingly, this is one of several species of frog that seemed to disappear from much of its range about 25 years ago due to chytrid fungal infections, but seems to have made a partial comeback.
Sachatamia ilex range map from IUCN Redlist Database
We found several of these Ghost Glass Frogs along a rocky stream at the Costa Rican Amphibian Research Center in the evening after some heavy daytime rains.
Like many glass frogs (Centrolenidae), the call of this species is a high pitched single note in the 7-8kHz frequency range. To my ear, the call of the Ghost Glass Frog sounds like a high pitched "tsip". When we heard them, this single "tsip" was repeated every 4-5 seconds from the leaves where they sat and called.
The Parachuting Red-eyed Leaf Frog (Agalychnis saltator) is another bright green leaf frog from the tropical lowlands of the Atlantic versant of northeastern Costa Rica. There are also disjunct populations in northern Nicaragua and eastern Honduras. This frog is similar looking to the Red-eyed Leaf Frog (A. callidryas) but lacks the light striping within the lateral blue side stripes
Agalychnis saltator range map from the IUCN Red Database
The curious name "Parachuting" Leaf Frog is a reference to their habit of leaping down from high in the tree canopy down onto lower leaves for reproduction. As they drop, they spread their toes and use their widely webbed feet to slow their descent.
Males of this species call from leaves near or over water edges. The individuals we found were calling from much higher leaves than the congeneric species of leaf frogs which share their breeding ponds. A couple of males were calling 3 or 4 meters off the ground.
To my ear, the call of this species is a short dry "wreck" or "ruck" sound. It has a carrier frequency around 2300 Hz, quite a bit lower than other Leaf Frogs. Here is short recording of two A. saltator calling back and forth (with a couple of the higher "pip" of A.lemur towards the end) .
In this second recording, you hear more of what it sounded like with several other species calling with the A. saltator.
The Mahogany Treefrog (Tlalocohyla loquax) was kind of a white whale for me. I have been herping and looking for frogs in its range many times over the last 40 years and although I've found a lot of other frog species in that range, I could never find or hear a Mahogany Treefrog!
Mahogany Treefrog range map from IUCN Redlist
Tlalocohyla loquax is not a rare frog, ranging from the lowlands of the northern isthmus of Tehuantepec (where I have herped), over most of the Yucatan platform (where I have traveled extensively), and down into Belize (where I failed to find them) and down into northern Costa Rica (where I also failed to find them). Other herper friends would often chuckle at my inability to find this relatively common species considering how much travel I had done within their range.
Finally in August 2025, I was able to find my white whale! While searching for frogs at the Costa Rican Amphibian Research Center, Brian led us to one of his ponds in the forest and we immediately heard the percussive calls of this species. We heard two of these frogs calling back and forth at this small pond, but because they were calling from a heavily vegetated area away from the edge, we couldn't see them. We came back to that pond on multiple occasions in the days we were there and still couldn't find them. Finally on our last visit, Tim was determined to find one of these frogs to show me and eventually his eagle eyes spotted one way back through the vegetation. I was able to snap the photo posted above. My trip was complete - I had my white whale both in a photo and a recording!
To my ear, the call of this treefrog is percussive "deck" or "puck" often repeated as a double "de-deck". In this recording you can hear a couple calling on the left side. You also hear the "creek" calls of the Hourglass Treefrog (Dendropsophis ebraccatus) with the nasal trill of the Olive Snouted-Treefrog (Scinax elaeochroa) and, of course, the metallic "tinks" of Tink Frogs in the background.
In this second recording, you can hear how the notes become more complicated as the frogs start calling more often, producing a "de-de-deck" sort of call.
I found several much rarer species on our trip. But getting this frog onto the lifelist was still one of my anuran highlights of our trip!
San Carlos Treefrog (Dendropsophus phlebodes) Chilamate, Costa Rica
The San Carlos Treefrog (Dendropsophus phlebodes) is one of the small "yellow treefrogs" in the genus Dendropsophus. This genus is one of my favorite frog genera simply because they are cute. For some reason, even though I've found lots and lots of D. ebraccatus and D. microcephalus, I could never find this species before this trip. Once I found my first ones, of course I found a lot of them! Typical. 🙄
This species occurs in lowland forested areas on the Atlantic versant of Nicaragua through central Panama and then across both sides of the Darién into NW Colombia. Although I found my first D. phlebodes in an area of regrown rainforest, this species is very adaptable to disrupted habitats and we also found them calling in garden ponds and flooded agricultural lands.
San Carlos Treefrog range map from IUCN Redlist
I think one of the reasons I may have taken so long to find this species is how similar its call is to the other Dendropsophus. Like the Hourglass Treefrog (D. ebraccatus), the San Carlos Treefrog has a raspy "creek" call. However, it differs from the Hourglass Treefrog in that the calls have a series of trailing repeats after the main "creek" pair. I will make a comparison post for the three Central American Dendropsophus soon.
The Lemur Leaf Frog (Agalychnis lemur) is a delicate looking leaf frog with a big head and eyes. It is a rather strange looking frog and always looks a bit emaciated to me? Their long "spidery" legs contribute to them being very good climbers.
Most of the individuals we saw were lime green with red speckles or blotches around the body, which I think contributes to its "unhealthy" look. But this is their normal coloration.
Even though this particular frog appeared healthy, this species is not. This species is regarded as Critically Endangered by the IUCN. It originally ranged from in the Caribbean foothills from northern Costa Rica through Panama. However, most of its populations were extirpated during the last 30 years, presumably by the spread of the chytrid fungus that has ravaged frog populations worldwide. It survives in a few disjunct populations through its former range. We were lucky to see and hear a large number of this species at the Costa Rica Amphibian Center near Siquirres, Costa Rica (the top yellow "blotch" in the red zone of extinction in Costa Rica on this map). Although this map suggests the species is still extant over much of its range in Panama, it has also disappeared from much of that range as well.
map from IUCN Red List Database
I'm always surprised when I listen to neotropical frog calls by how many species have short one syllable "tik" or "pik" or "tink" calls. They can sound very similar to my ear although they often differ in pitch and the frequency with which they are repeated.
The call of this species is one of those subtle, single syllable calls. To my ear it is more of a "pip" than a "tink".
In this recording, you will hear the chattering "creek-crk-crk" calls of the Hourglass Treefrog (Dendropsophus ebraccatus) and then at around 3, 6, and 11 seconds you will hear a loud "pip". That pip is our Lemur Leaf Frog. In the background you can also hear the more metallic "tinks" of the Tink Frog (Diasporus diastema). Even though the call of the Tink Frogs is also a single syllable, you can hear how it differs in pitch and "tone".
