Tallying Amphibians from the United States, Canada, and Mexico

Our recent post about reaching 300,000 species raised some interesting questions about how long it will take for iNaturalist to log all species for various groups in various locations. This is difficult to do for many groups and locations because of taxonomic issues. One group that’s fairly well known, at least in North America, is amphibians. The number of amphibian species observed on iNaturalist in the United States, Canada, and Mexico does seem to be saturating.

But how many species remain? We wrote a post on this for Amphibians in the United States three years ago and counted 13 missing species. We re-crunched these numbers again for the United States as well as Canada and Mexico which together make up the three most observose countries on iNaturalist.

In the United States, all but one of those missing 13 species has been found. We now count that 316 of 318 species thought to occur in the United States are represented on iNaturalist by at least one verifiable observation. The two missing species are Blanco Blind Salamander (Eurycea robusta) and Reticulated Siren (Siren reticulata). The former is only known from a single specimen found in Texas 40 years ago and the latter is a species recently described from Georgia and Alabama two years ago.

In Canada, we count that all 48 of 48 species thought to occur in Canada are represented on iNaturalist by at least one verifiable observation. We’re counting these based on observations anywhere in the world, not just in Canada, and there are no amphibian species endemic to Canada (i.e. found nowhere else in the world) so this makes sense given our numbers from the United States.

In Mexico, only 300 of 424 species are represented on iNaturalist (71%). While there are fewer observations from Mexico than the United States on iNaturalist, this is also driven by a large number of Mexican species with extremely small ranges. Many are only known from one or two sites.

For example, in the State of Tamaulipas 3 species that haven’t been observed on iNaturalist occur. All three are endemic to Mexico. They are:
Graceful Splayfoot Salamander (Chiropterotriton cracens)
Tamaulipan Arboreal Robber Frog (Craugastor batrachylus)
Dennis' Chirping Frog (Eleutherodactylus dennisi)

Tamaulipan Arboreal Robber Frog (Craugastor batrachylus) is also found in Querétaro where it represents the only species that occurs in Querétaro that hasn't yet been observed. Chihuahua, Morelos, Distrito Federal and Tlaxcala also each have one species that hasn't been observed. They are:
Lemos-Espinal's Leopard Frog (Lithobates lemosespinali) (Chihuahua)
Morelos False Brook Salamander (Pseudoeurycea altamontana) (Morelos & Distrito Federal)
Roberts's Tree Frog (Sarcohyla robertsorum) (Tlaxcala)
Jalisco has four species that haven't been observed. Two of them can also be found in Colima. They are:
Jalisco Trilling Frog (Eleutherodactylus jaliscoensis)
Sierra Manatlán Trilling Frog (Eleutherodactylus manantlanensis)
Colima Shiny Peeping Frog (Eleutherodactylus orarius)
Sierra Huichol Peeping Frog (Eleutherodactylus wixarika)

In Hidalgo, we can also find Roberts's Tree Frog (Sarcohyla robertsorum) as well as the following three species:
Cave Splayfoot Salamander (Chiropterotriton mosaueri)
Least Chirping Frog (Eleutherodactylus verruculatus)
Puebla Tree Frog (Sarcohyla charadricola)

While we are missing no species from some states like Sonora and Sinaloa, 6 other states have more than 5 missing species. These states tend to be in the mountainous tropical parts of the country and are as follows:

Michoacán (6 species):
Ambystoma amblycephalum
Eleutherodactylus erendirae
Eleutherodactylus floresvillelai
Eleutherodactylus nietoi
Eleutherodactylus orarius
Lithobates dunni

Puebla (10 species):
Chiropterotriton casasi
Craugastor galacticorhinus
Eleutherodactylus verruculatus
Lithobates pueblae
Megastomatohyla nubicola
Sarcohyla charadricola
Thorius dubitus
Thorius magnipes
Thorius maxillabrochus
Thorius schmidti

Veracruz (16 species):
Aquiloeurycea praecellens
Chiropterotriton casasi
Chiropterotriton nubilus
Chiropterotriton perotensis
Chiropterotriton totonacus
Ecnomiohyla valancifer
Eleutherodactylus verruculatus
Isthmura corrugata
Lithobates chichicuahutla
Megastomatohyla nubicola
Pseudoeurycea granitum
Sarcohyla pachyderma
Sarcohyla siopela
Thorius dubitus
Thorius magnipes
Thorius narismagnus

Chiapas (12 species):
Charadrahyla chaneque
Craugastor amniscola
Craugastor brocchi
Craugastor matudai
Craugastor pozo
Craugastor taylori
Dendrotriton megarhinus
Dendrotriton rabbi
Exerodonta chimalapa
Plectrohyla pycnochila
Pseudoeurycea brunnata
Ptychohyla dendrophasma

Guerrero (19 species):
Bolitoglossa coaxtlahuacana
Craugastor uno
Eleutherodactylus erythrochomus
Exerodonta melanomma
Incilius cycladen
Pseudoeurycea ahuitzotl
Pseudoeurycea amuzga
Pseudoeurycea kuautli
Pseudoeurycea mixcoatl
Pseudoeurycea tenchalli
Pseudoeurycea teotepec
Quilticohyla erythromma
Sarcohyla chryses
Sarcohyla floresi
Sarcohyla mykter
Sarcohyla toyota
Thorius grandis
Thorius hankeni
Thorius infernalis

Oaxaca (39 species):
Bolitoglossa oaxacensis
Bolitoglossa riletti
Charadrahyla chaneque
Charadrahyla esperancensis
Craugastor polymniae
Craugastor silvicola
Craugastor uno
Ecnomiohyla echinata
Exerodonta chimalapa
Exerodonta melanomma
Ixalotriton parvus
Megastomatohyla mixe
Megastomatohyla pellita
Pseudoeurycea anitae
Pseudoeurycea aquatica
Pseudoeurycea obesa
Pseudoeurycea orchileucos
Pseudoeurycea papenfussi
Pseudoeurycea smithi
Pseudoeurycea unguidentis
Sarcohyla calvicollina
Sarcohyla celata
Sarcohyla cembra
Sarcohyla crassa
Sarcohyla cyanomma
Sarcohyla cyclada
Sarcohyla labedactyla
Sarcohyla miahuatlanensis
Sarcohyla psarosema
Sarcohyla sabrina
Thorius aureus
Thorius boreas
Thorius insperatus
Thorius longicaudus
Thorius minutissimus
Thorius narisovalis
Thorius pinicola
Thorius pulmonaris
Thorius tlaxiacus

This exercise is a reminder that in tropical regions such as many of Mexican states, its not just that there are often more species than in temperate regions but that many species often have much smaller ranges. As a result, observing them requires observations from all corners of the country. We're fortunate to have many very knowledgeable Mexican amphibian identifiers (e.g. @cris-tzabcan, @coatzin_tutor, @yamaneko, @eligarcia-padilla, @opuntia24, @josecamx, @pedro_nahuat, @jhvaldez_tutor, @lucareptile, @rene_vela, @sonoran) and observers who have seen many Mexican amphibian species (e.g. @alejandrocalzada, @juancruzado, @eligarcia-padilla, @wouterbeukema, @pedro_nahuat, @jesusrc7, @horacio_barcenas, @el_neotropico, @esauvaldenegro, @alejandromijangosbetanzos, @oscarleonardo32, @sandboa, @cris-tzabcan, @dianafr) participating in iNaturalist/Naturalista.mx. It will be interesting to see how much longer it takes to find these missing Mexican amphibian species.

Posted by loarie loarie, November 04, 2020 01:18



Thanks for this interesting tally. 🐸

Posted by botanicaltreasures 9 months ago (Flag)

Thanks for this very interesting write-up! Australia is also missing a few species observations on iNaturalist, so it's interesting to see what other countries have/have not seen in terms of amphibians! :)

Posted by twan3253 9 months ago (Flag)

I think Eurycea robusta is going to remain missing for a while longer. Attempts to even find the location of the original drilling site have been difficult and there is no known access point to this population that is open to the surface.
As for Mexico, I think a lot of it is bad timing. I know quite a few of us used to travel extensively in Mexico in pre-iNat days documenting what we could based on the meager published resources there were. Now that there is a lot more published information, Mexico is harder to travel to and within. Hopefully some of our Mexican iNat users can fill in those gaps while there is a dip in ecotourism to that beautiful country.

Posted by sandboa 9 months ago (Flag)


Posted by yayemaster 9 months ago (Flag)

Fascinating! Time to look for some Reticulated Sirens.

Posted by wildlandblogger 9 months ago (Flag)

Thanks! Very interesting!

Posted by alejandrocalzada 9 months ago (Flag)

Niece and interesting post @loarie. Much to do in Mexico, but it's a matter of time, more and more NaturaListas has been joining... Saludos

Posted by jhvaldez_tutor 9 months ago (Flag)

maybe Rana boylii Foothill Yellow-legged Frog should not be included in the Amphibians of Canada as seems like it is really restricted to a couple of western US states - then Canada would be 47 of 47 with at least one observation of each species within Canada :)

Posted by marykrieger 9 months ago (Flag)

A pity the place-checklist download does not include the date first seen [it includes the first and last seen observation links] - and actually download the filtered data (as per above, rather than the entire checklist)
Would love to do similar analyses for more taxa for some southern African countries.
What is cool is that the shape of the curve suggests that the USA has recorded most of its frogs, but it may reveal an estimate of undescribed species in some areas, especially if undescribed species found and recorded on iNat are factored in.
One little glitch for us is that our checklist includes "prohibited" species on the national watch list. (e.g. https://www.inaturalist.org/projects/nemba-prohibited-species-south-africa), but fortunately none of these has been recorded here yet.

Posted by tonyrebelo 9 months ago (Flag)

We have a lot of the Mexican species that are missing documented. The problem is they are all pre- inat and I have them all on Dropbox. I am trying to figure out a way to automate a way to move my observations from my dropbox account to inat. I had thought about waiting until inat comes out with a dropbox plugin.

Posted by sonoran 9 months ago (Flag)

For anyone interested in the IUCN range-maps for amphibians (and other animal groups) you can download most of the spatial date here:


The files tend to be a bit large as they're part of the global database. They're shapefiles, so they'll open in most GIS applications, including Google Earth, but they tend to overwhelm Google Earth.

Posted by earthknight 9 months ago (Flag)

Thanks you I appreciate it. I hope more identifiers join Naturalista as well as observers to decrease those lists

Posted by rene_vela 9 months ago (Flag)

Hi @loarie! nice work. I'm interested in compiling a list of species of amphibians and reptiles from Mexico that lack any sort of distribution map. I will be making these maps as a hobbie, but I just don't know enough programming to scrape the site and automatically generate such list.

Do you know anyone that could help?

BTW shout out to @smrovito who is on a rampage uploading incredible photos of rare amphibians! mostly of ones listed in this piece. Absolutely stunning stuff!

Posted by josecamx 9 months ago (Flag)

I have pictures of the Reticulated Siren captured by Steen in 2009! It was brought live to my house by our mutual friend Sean Graham where he lived in our "guest trailer". It has been interesting watching them over the years working to finding specimens and then doing the hard work of describing it. Fortunately Sean is a gifted storyteller and wrote up this epic tale for posterity:


Posted by rogerbirkhead 9 months ago (Flag)

Very cool story rogerbirkhead - thanks for sharing. Great tale of discovery! If you add the date/location of capture to your photo it counts as a non-captive observation (or encourage Sean Graham or David Steen to post!) - or wait for someone to track one of these down but from the story sounds like that was a pretty crazy undertaking

Posted by loarie 9 months ago (Flag)

@josecamx every Mexican amphibian on iNat currently has a 'taxon range' but only some of these are the IUCN ranges, others were carved up from the IUCN ranges or for taxa known from single localities just circles over the published type localities. If you updated any 'bad' taxon ranges that would be much appreciated. Let me know if I can help with anything.

Posted by loarie 9 months ago (Flag)

@loarie done. https://www.inaturalist.org/taxa/922243-Siren-reticulata
I'll try to get better locality data for it in the near future.

Posted by rogerbirkhead 9 months ago (Flag)

@loarie You're right! I mean Reptiles, many of them are lacking range maps, so it would be awesome to have a list of Mexican Reptiles lacking this info. Thanks again.

Posted by josecamx 9 months ago (Flag)

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