Ciudad de Mexico, Puebla, Veracruz, Oaxaca, Chiapas

From the 28th of July until the 1st of September 2023

Depending on which list you follow, Mexico typically ranks at a very honourable fifth or sixth place in lists of most biodiverse countries. When looking at just amphibian and reptile diversity, we see a similar picture. With as many as 1421 species of amphibian and reptile, the country straddles somewhere in the top ten as well. Only Australia has more reptile species and only six countries have more amphibian species. With such staggering numbers of species (and also such iconic species!) a revisit to Mexico was long overdue. Back in 2019 we had an excellent time traveling in Southern Mexico and already found a large number of interesting species. But due to the dry conditions we also missed seeing several of our main targets. One of those is the Yellowbelly Mushroomtongue Salamander (Bolitoglossa flaviventris). We searched very hard back then, but to no avail. Now, some years later, Laura has added some new information to the database and made some excellent new contacts. Besides missing some main targets, further up north there is a whole new species composition. Wouter has been gathering spots for some years now and built up quite the collection. Additionally I found some very cool locations along the coast. So Wouter, Laura and I made a plan where we would have more chances of seeing our top salamander target, as well as seeing a whole new range of species. Besides us three, long-time herping, birding, swimming buddy Sander Schagen joined for the entire trip. Sadly Wouter could only go for three weeks, but new herping buddy Robin Gloor from Switzerland joined us for the last two weeks.

Our trip coincided with the rainy season which starts earlier in the year, around May or June. But as local people already told us, the rains have become less frequent and less predictable over the past years. On our last trip we didn't have a single drop of rain despite being in the rainy season. This trip was different and in multiple locations we were blessed with some rain to lure the animals out. Only at the coast the rains became less frequent and at some locations we didn't have any noticeable precipitation. This made the herping at the beginning of the trip much easier than it was during the last two weeks. 

Axolotls indicating notable locations during our trip.
Axolotls indicating notable locations during our trip.

All images © Laura & Bobby Bok (unless stated otherwise)

Herping in Mexico is like a playground! The team for the first three weeks: Wouter, me, Laura and Sander.
Herping in Mexico is like a playground! The team for the first three weeks: Wouter, me, Laura and Sander.

Ciudad de Mexico

28th until the 30th of July 2023

Long-haul flights will never be my favourite, but at least we didn't have any stopover or big delays. From Amsterdam we flew straight to Mexico City where we arrived in the evening. Everything went very smoothly and before we knew it we were at the hotel. While having a cigarette in front of the hotel I found out people here don't sleep much and only visited this hotel for an hour or so. We on the other hand spend a proper night here and wandered what this big yellow banana was doing in our room? 

The next morning we met up with herping extraordinaire, scientific illustrator and new amigo René Villanueva Maldonado. We wanted to try our luck for Mexican Lanceheaded Rattlesnakes (Crotalus polystictus) and he knew just the spot for it. Like on our previous visit to Mexico, I had the honour of finding the first species of the trip - and a highly iconic one at that! Within minutes I found the first rattlesnake basking between the tall grass after which Laura and René found even prettier individuals. Other species seen here were Sceloporus grammicus and Barisia imbricata.

It got hot quickly so we decided to head for higher, and more importantly, cooler grounds. Getting out of the city was a hassle, but in the afternoon we arrived in some beautiful open pine forest and, without long, started seeing many different species, such as Pseudoeurycea leprosa, Hyla eximia, Sceloporus aeneus, Sceloporus anahuacus, Sceloporus mucronatus, Sceloporus torquatus, Barisia imbricata and Plestiodon copei.  Wouter even managed to find a young Dusky Rattlesnake (Crotalus triseriatus). Then a big thunderstorm hit. The loudest thunder imaginable struck nearby and big hailstones fell from the sky. We took shelter in a nearby abandoned building before running back to the car as soon as the precipitation got less. In a nearby restaurant we had dinner before driving back into the city and saying goodbye to René. Thanks again so much for showing us around amigo!

The next day we drove east and hiked up an extinct volcano to search for a rare salamander. On the way up we noticed how the woods here are picked clean. People collecting fire wood make sure there are very few suitable logs left to decompose. This makes searching for salamanders a little harder, but luckily not impossible. Wouter found a very good log with not only Pseudoeurycea leprosa, but also Pseudoeurycea altamontana. After admiring these salamanders through the lenses of our cameras we hiked on. Well above 3500m absl we found the stream. At this altitude the aquatic salamanders we were after should be safe from invasive trout. Sadly this was not what we found. In the deeper parts of the stream we saw some young trout swimming, which was not very promising. But as usual, persistence paid off and Wouter found our first ever Ajolote: a Leora's Stream Salamander (Ambystoma (altamirani) leorae). A deeper pool even held large numbers of this critically endangered (sub)species. Moreover, while all individuals were neotenic with external gills, I also found a single big adult without gills. When the rains arrived, the temperature dropped quickly at this altitude. We were not well prepared for cold weather, so we hiked down back to the car and drove to the next location.

Puebla - high altitude deserts

30th of July until the 1st of August 2023

We arrived late at the next accommodation and after quickly dropping our luggage, we drove into the nearest town. Here we found the tiniest restaurant, but with the tastiest tacos of the whole trip. We kept on ordering more because they were simply delicious! On the drive back to the hotel it was raining, so we decided to check nearby spots for amphibians. Already when we were about to drive into a dirt track, we were stopped in our tracks by a Mexican Spadefoot (Spea multiplicata).

The next day it was sunny, so we had hoped for some reptile bonanza. But despite the good conditions, there was surprisingly little reptile activity and we only found a few Sceloporus megalepidurus and Aspidoscelis gularis. We decided to try our luck for a rarely seen and range-restricted salamander further north. Logging, forest fires and overgrazing gave us a hard time locating proper habitat. But late in the afternoon Wouter found a nice slope with some suitable habitat which we decided to check out. Turning rocks quickly delivered a huge number of reptile species such as Barisia imbricataSceloporus bicanthalis, Sceloporus grammicus, Sceloporus megalepidurus, Sceloporus torquatus, Phrynosoma orbiculareConopsis lineata, Thamnophis scalaris and finally also a few individuals of our main target, the Cofre de Perote Salamander (Isthmura naucampatepetl). While collecting something from the backpacks, I noticed a snake crawling around there, which turned out to be another Dusky Rattlesnake (Crotalus triseriatus). In the evening we tried our luck with roadcruising, but with low temperatures and strong wind the weather was not on our side. In a nearby forest we had more luck, as the rains brought out some amphibians, such as Lithobates montezumae, Hyla eximia, Ambystoma velasci and Aquiloeurycea cephalica

The next day started with a flat tire, so much later than we had anticipated we arrived in suitable habitat. Yes, it was hot already, but obviously not too hot, as it was Sander who flipped our main target under some trash next to the road: a stunning Huamantlan Rattlesnake (Crotalus scutulatus salvini)! We also saw Aspidoscelis costatus, Aspidoscelis gularis and a small Conopsis acuta. At a stunning lake with saline and alkaline waters we searched for another salamander specialty of the region. We scrambled along the stromatolite formations along the shores, but the water levels were low, making the shores steep and our search futile. We only found Spea multiplicata, Phrynosoma orbiculare and Sceloporus megalepidurus. We thought of returning in the evening, but basically everybody we talked to recommended to not visit at night due to the safety situation. Sensible as we are, we decided to listen and drive on to the next location. 

Veracruz - west of the Sierra Madre Oriental

1st until the 3rd of August 2023

Shortly before sunset we arrived at our accommodation. The restaurant was closed already, but pizza delivery from the nearby town saved the day. So after a tasty pizza in our cabin we descended into the forested stream in the valley below. We barely started searching when Sander said he found something. It turned out to be our main target for the area, and we weren't expecting to find it at night already. Two Bromeliad Arboreal Alligator Lizards (Abronia taeniata) were working on the conservation of their species. What an amazing sight! We also found some special frogs, such as a male Porthole Tree Frog (Charadrahyla taeniopus) and a massive Moore's Frog (Lithobates johni). Other frogs along the stream included Rheohyla miotympanum and Lithobates berlandieri. Also several Cacomistles (Bassariscus sumichrasti) were seen hunting in the canopy.

The next morning we took it easy, and after a massive breakfast we went into the stream for a swim. Because there were many other people out and about, herping was a little on the slow side with only the occasional Sceloporus formosus observed. We did find some good places to flip rocks, and hoped to find one of our main salamander-targets of the trip, a huge Isthmura gigantea, but sadly that wasn't in the cards for us. After dinner, we did some roadcruising, but again the low temperatures prevented any mentionable success. Back at the cabin, we did a small round at the forested stream, but also this didn't deliver any more highlights. 

Time to leave our cozy cabin behind and explore new horizons. After another big breakfast we got in the car and drove to a nearby extinct volcano to search for salamanders. We didn't have much luck with those and only Wouter found a small Pseudoeurycea leprosa. In general it was a slow day with only the occasional Sceloporus torquatus, until Laura encountered a specialty of the region: Mexican Smallheaded Rattlesnake (Crotalus intermedius). An awesome find and just in time before a big rain shower hit us. 

Veracruz - east of the Sierra Madre Oriental

3rd until the 6th of August 2023

In the late afternoon we arrived at our accommodation for the next three nights. It was surprisingly hard to find an open restaurant in the rather big town, but of the few options we had we chose very poorly. It took well over an hour for the food to arrive, and when it did, it was a very sad sight and lacked any taste. We opened some crisps and went out for some urban herping. The rains caught up with us again, but at least we found some species out and about because of that. Searching along a road going through some disturbed forest we found Incilius valliceps, Lithobates berlandieri, Rheohyla miotympanum, Anolis laeviventris and between some leaf litter I spotted a Broken-ringed Earth Snake (Geophis semidoliatus).

Today we ventured north to explore some beautiful open oak forests, interspersed with old lava flows and agricultural land. While searching for salamanders, Wouter found a Green Arboreal Alligator Lizard (Abronia graminea) subadult hiding in a bromeliad. Later in the afternoon I found an adult of the same species, basking on a branch. Incredible how similar these lizards are to the old world chameleons, both in habitat choice as well as behaviour. We also found some other reptiles, such as Sceloporus bicanthalis, Sceloporus grammicus, Sceloporus mucronatus, Thamnophis scalaris and Huaxteca Lesser Galliwasps (Siderolampus enneagrammus). After a roadside dinner we headed back into the forest. A completely different species composition was awaiting us. Near dry stone walls we first found some small Giant False Brook Salamanders (Isthmura gigantea) until Laura spotted a very impressive individual. Incredible to see a salamander this size staring back at you from inside its burrow! Also some snakes were out and about, such as Geophis multitorques and Ninia diademata. The old lavaflows were a good spot for amphibians and here we found the critically endangered Pygmy Splayfoot Salamander (Chiropterotriton lavae) crawling over moist rocks as well as Craugastor decoratus and Craugastor mexicanus. It was absolutely marvelous to herp in these species rich forests, and except for missing Ophryacus here, we basically got all our other desiderata. Still, it was also a sad sight, because from every angle humans are chopping up the forests to make way for agriculture and mines. A few years from now and there is probably nothing left here...

Today a big hike was on the menu. We met up with local naturalist Aarón Arias to climb the slopes of the Cofre de Perote. Our target here was the type locality of the recently described Isthmura corrugata. Only two individuals are known of this very special fossorial salamander, and with the rain of the previous night we got our hopes up. During the steep ascent of the mountain we saw two Leptodeira maculata, Scincella gemmingeri and a single Anolis tropidonotus, but in general the forest was eerily quiet. When we finally got close to the type locality we had to negotiate permission to search the forest, but luckily the local communities were very friendly. However, the forest was very much degraded and the collecting of fire wood made sure there were not many things to flip. We tried until shortly to sunset when we had to give up. It was a high risk, high reward kind of situation, but at least we could give it a decent try. The hike down was a slippery affair, but after a few hours we were back at the car. With Jodi Bernal blasting from the speakers we were having a proper dinner back in town before we knew it. Great meeting you Aarón, we'll be back for another attempt for sure!

Veracruz - Zongolica

6th until the 11th of August 2023

We all much desired to see the Broadfoot Mushroomtongue Salamander (Bolitoglossa platydactyla), but were not sure whether we would have a chance to see them around our next stop, Zongolica. Thus, we drove into a city where we had contact to someone who supposedly has this species in his garden. When we arrived we had a very warm welcome by Rogelio. After having bridged the language gap, Rogelio and Team Salamander were on their way to Rogelio´s former family home in the next city. It looked like the garden only receives some grooming whenever salamander enthusiasts from Europe visit, and the last time seemed too long ago...Still, the perfect place for salamanders, and flipping delivered two individuals after searching for quite some time. 

Quite happy to have seen this salamander we arrived at Zongolica. But, as it turns out, Bolitoglossa platydactyla is rather common here, and at least during the first night here we saw a great many of them. If only we had known before... It didn't matter much, because it is always good to see more salamanders, and we were happy to be at Zongolica. This place is legendary and many herpers from all over the world have visited the excellent lodge run by Miguel Ángel de la Torre-Loranca and his family. We stayed in the very comfortable cabins from where we could explore the surroundings. The first night we made plans for the upcoming days and I had a quick peek at the stream below the cabins. Despite the moist conditions I only saw some Craugastor loki and Ptychohyla zophodes.

In the morning we took it easy and enjoyed ourselves around the cabins. Many Sceloporus variabilis were running around and Miguel found a massive Giant False Brook Salamander (Isthmura gigantea) which measured 34cm. According to Jean Raffaëll the largest individual of this species ever recorded was 32,7cm,  which makes this individual the largest known. This also makes it the same size as the largest terrestrial salamander in the world, which is Dicamptodon.

So this must be the biggest individual ever recorded of Isthmura gigantea and as big as terrestrial salamanders can get. An incredible animal and such a cool experience! Miguel also found a very cool little snake which was only recently described and is named after him: a Loranca's Earth Snake (Geophis lorancai). In the late afternoon we drove up to a karstic mountain peak with a very interesting species assemblage. Here we saw some iconic karst-dwelling species such as Knob-scaled Lizard (Xenosaurus grandis) and Crowned Tree Frog (Triprion spinosus). Other species seen included Craugastor decoratus, Aquiloeurycea cafetalera, Ninia diademata, Rhadinaea forbesi and Tantilla schistosa.

Recent studies have shown that the Green Arboreal Alligator Lizard (Abronia graminea) is in fact not one species, but a complex of several species. Having seen the northern clade, we of course also wanted to see this candidate species, simply because they are stunning animals. It took us quite a while, and at first we only saw a few Sceloporus formosus. At last, Miguel found a beautiful subadult hiding between the moss on a tree trunk. After dinner we drove towards another karstic mountain range, where some cave-crawling was on the menu. It didn't take us long to find our main target here, and we found several Jaguar Salamander (Pseudoeurycea jaguar) and a single Giant False Brook Salamander (Isthmura gigantea). Afterwards we explored a road bank for vipers and it took Laura maybe 10 minutes to spot a beautiful Mexican Horned Pitviper (Ophryacus undulatus) hanging in the vegetation. After looking for this species at quite some different locations, the success felt very sweet. Also some other snakes were on the move, such as Coniophanes fissidens, Chersodromus liebmanni and Ninia diademata. In the vegetation we spotted several Anolis schiedii sleeping. 

Today we had to attend to some chores like finding an atm, doing our laundry, getting our flat tire fixed (for a second and third time this trip!) and trying to find a new camera for Wouter, since it wasn't functioning properly anymore. Luckily the evening turned out to be much more interesting, and in the stream below the cabins we found several frog species, such as Ptychohyla zophodes and Rheohyla miotympanum. After carefully checking the underside of leaves overhanging the stream we even located some Northern Glassfrogs (Hyalinobatrachium viridissimum). Close to the stream Miguel found a beautiful Mexican Jumping Pitviper (Metlapilcoatlus nummifer), which was such a friendly and shy snake, despite the impressive threat display. Sleeping in the vegetation I found a Golden-headed Garter Snake (Thamnophis chrysocephalus) and Wouter's bark peeling delivered a Veracruz Pygmy Salamander (Thorius pennatulus). 

Sander and I explored the stream during daytime and found out it is also well suited for swimming. We even found some of the Glassfrogs of the previous night back. In the afternoon we drove towards another mountain peak to search for Jaguar Salamanders (Pseudoeurycea jaguar). After seeing some nice but dark individuals, we had hoped to find a spotted one in this second population. The conditions were incredibly dry, but we kept on trying until Miguel indeed found another Pseudoeurycea jaguar. Unfortunately, this individual was unspotted as well. Other species seen included Isthmura gigantea, Xenosaurus grandis, Sceloporus aureolus, Ninia diademata and Rhadinaea forbesi. After that, we were ready to give up because of the dry conditions, but luckily Laura motivated us to search a few more bromeliads. Indeed, after a while Wouter peeled a Common Splayfoot Salamander (Chiropterotriton chiropterus) from inside a bromelia. 

Southeastern Puebla

11th until the 13th of August 2023

Miguel joined us for one more day to search for a very special viper, endemic to southern Puebla and adjacent Oaxaca. While driving south we had some small stops along the way without any noteable highlights. In the late afternoon we arrived at some slightly disturbed, but seemingly good habitat where Miguel has had luck in the past. We saw some Sceloporus spinosus, and under rocks we found several snakes such as Conopsis acuta, Tantilla bocourti, Tantilla rubra and even a couple of Mexican Pygmy Rattlesnakes (Crotalus ravus). But no sign of our main target... Miguel knew a taco restaurant close by where we had an amazing dinner (gringas!) before saying goodbye to him. Thanks a lot for an incredible few days Miguel! Afterwards we went to the hotel, before checking out a nearby spot for some roadcruising as well as searching for the drought-adapted Puebla Tree Frog. Unfortunately, it was cold and windy and we didn't find anything, neither on the road nor in a stream-valley below. 


The next day we ventured a bit higher up to reach certain known spots for salamanders. Much to our disappointment, much habitat has disappeared already and many forests have been transformed into agricultural land or cow pastures. Eventually we did find a good forest, and within a few steps Wouter spotted a very big Mexican Bull Snake (Pituophis deppei) hanging in a tree. We also saw Hyla plicata, Sceloporus formosus, Thamnophis conanti and a local person hinted us towards a beautiful Green Arboreal Alligator Lizard (Abronia graminea) of the southern clade. We had an early dinner at the same amazing restaurant as the day before, and again it was delicious. While the sun was painting the sky red, we hiked between the rolling hills and some beautiful desert scenery. Our goal was to reach one of the few places where there is water flowing in the desert landscape. We heard a Puebla Tree Frog (Exerodonta xera) calling, but despite scrutinizing the call site we could not find the frog. Just when I had said: "Maybe the belief is wrong, and Mixcoatlus CAN be found in wetter areas", and Laura had set out to the wettest part in the hope to find salamanders (which definitely should be here as well!), she saw a small snake emerging from a rock wall bordering the grassy meadow. A viper, she called, and, directly after: "It's a Mixcoatlus!". After searching a lot for this species during the day we didn't expect to find it now and certainly not in this habitat. But then we saw several flashlights coming in our direction. A small group of what turned out to be rangers explained to us that we were trespassing. We were not aware of that fact, as we didn't see any signs along the road, but we apologized, and luckily it wasn't a big problem after that. When they had left, we could finally focus again on that beautiful little viper! Apart from the viper it was a slow night, and Laura only found a Tantilla flavilineata. Back at the car we ate the remaining gringas and did some star-gazing before driving back to the hotel.

Oaxaca - Ixtlan de Juárez

13th until the 15th of August 2023

A small search in the morning didn't deliver any reptile sightings, so we soon were on our way to further south - into a new state and into completely different habitat again. After a touristy stop at the Mirador de Cristál and some excellent tacos, we headed into high altitude pine forest. Conditions were rather dry, but at a small stream we quickly encountered some interesting species such as Incilius occidentalis, Thorius pulmonaris and Geophis dubius. Later that evening it started to rain quite heavily, much to the delight of Hazel's Tree Frog (Sarcohyla hazelae) and Southern Highland Tree Frog (Hyla euphorbiacea). Unfortunately, our main target Isthmura boneti still eluded us in spite of those improved conditions. The next morning the rain was still falling hard, preventing us from searching for reptiles. But when the skies cleared around noon, some lizards such as Anolis quercorum, Plestiodon brevirostris and Sceloporus aureolus and Sceloporus formosus were quick to follow as they were keen on getting some sun. The following evening we searched again for our salamander target, again in vain, and largely found the same species as the previous night. 

Oaxaca - Sierra Juárez

15th until the 17th of August 2023

A winding road brought us up into the Sierra Juárez, a hotspot of biodiversity with many endemic species. Just below 3000m absl we found a cozy cabin to stay at the edge of a big meadow. We had a fireplace, which we tried to use on the first night to try and get warm. During our second night we found out why we didn't manage the previous night - the torrential downpour throughout the night had caused the roof to leak in some places, and the inside of the fireplace looked like some proper olm habitat. Water was literally flowing from the walls. The living room was flooded as well, so needless to say we didn't really get warm during our stay here. The conditions were not too bad to find salamanders though. We saw quite some species, such as Thorius boreas, Thorius macdougalli, Pseudoeurycea juarezi and Pseudoeurycea unguidentis. On the last night Sander even spotted a Muscular Salamander (Pseudoeurycea papenfussi). A highly endangered salamander that proved true to its name. Wouter had a hard time retrieving this animal from its burrow! But densities were low. Of most species we found a single individual, and they required a lot of searching. Surprisingly, we did not see any frogs, and of all the cool endemics that can be found here we saw exactly zero. Quite strange to have a beautiful cloud forest with streams and good conditions, and not hear a single frog calling. The one exception proved to be Craugastor pygmaeus, of which we found one individual. Unsurprisingly, reptiles were not particularly active either, but turning stones in the torrential rain delivered a few lizards such as Sceloporus grammicus and the endemic Mesaspis juarezi. At night we also found several Anolis tropidonotus. Snakes were also encountered. I found a Thamnophis lineri and Rhadinaea bogertorum, while Laura found the colourful, but incredibly annoying to photograph Geophis duellmani. After a day of flipping stones in the rain with frosty fingers, it was Wouter who struck gold (or rather silver) in the late afternoon and uncovered our main target for the area by finding a Oaxacan Dwarf Boa (Exiliboa placata) under a log. Our individual was in shed which is apparantly a common sight in this species according to Campbell & Camarillo 1992, and almost half of the animals they found where in shed.

And then it was time to leave for Oaxaca airport. Sadly Wouter could not join us for longer in Mexico and had to go back to the Netherlands. Sander, Laura and I would stay for another two weeks to explore the lowlands of Oaxaca and Chiapas. Although sad that Wouter couldn't join us, we were happy to welcome new herping buddy Robin Gloor in the team who had just arrived from Switzerland. We had lunch at the airport with all five of us, before we finally had to say goodbye. 

Herping in Mexico is like a playground! The team for the final two weeks: Robin, Laura, me and Sander.
Herping in Mexico is like a playground! The team for the final two weeks: Robin, Laura, me and Sander.

Oaxaca - Sierra Madre del Sur

17th until the 18th of August 2023

To break up our drive towards the next location, we stopped in the mountains between Oaxaca and the coast. After some tasty tacos we ventured into a disturbed patch of forest close to our accommodation. It didn't take long before Laura found exactly what we came for: two beautiful Oaxacan Mushroomtongue Salamanders (Bolitoglossa macrinii) climbing in the vegetation. We also found a sleeping Sceloporus formosus and some Craugastor mexicanus and Craugastor pygmaeus  hopping around.

After a night in our cabins (which smelled like wet dog), we drove to a nice waterfall nearby. Here we found many Holcosus undulatus running around as well as some Anolis zapotecorum.

Coastal Oaxaca

18th until the 22nd of August 2023

And then we were suddenly in a different world. At the coast we found a very comfortable apartment which was spacious, had a nice shower, air conditioning and a swimming pool. The town itself had restaurants with some very tasty seafood. In general there was a very holiday-like atmosphere. All giving us a very nice respite from some very disputable places where we stayed in the previous weeks. But then again, there was the thing with the climate at the coast... Having arrived from the mountains we had a hard time adjusting to temperatures of around 40°C and very high air humidity. And on top of that, the area had not received any rain recently. All searches in the forests during the day were basically futile and at night conditions were still very hard. In general there was very little snake activity and we had to make many meters for every species we found. 


During the day we saw species such as Aspidoscelis deppii, Anolis sagrei, Anolis nebulosus, Anolis unilobatus, Sceloporus siniferus and Urosaurus bicarinatus. We were also in iguana country again, and already when we arrived we saw a big Green Iguana (Iguana iguana) in the tree opposite of our accommodation. In a city park we found several shy Western Spiny-tailed Iguanas (Ctenosaura pectinata), sometimes even together with Green Iguanas in the same tree. The hot days were also suited for some more marine activities. During a boat tour on the Pacific Ocean we saw several sea turtles mating; one pair of Green Sea Turtle (Chelonia mydas), but mainly Olive Ridley Sea Turtle (Lepidochelys olivacea). It was a magnificent sight to be in the water with these gentle giants. Another species we were keen on finding was Yellow-bellied Sea Snake (Hydrophis platurus). After having seen the species for the first time in Costa Rica, I really wanted to be in the water with one. Luckily we were not disappointed, as Robin spotted an individual which I could carefully grab with my net. After a photo session, we released the snake close to where it was found. It was such a joy to see the snake disappear into the big blue! While photographing mating turtles extensively, I drained the battery from my underwater camera, so taking pictures or videos of this will have to wait until next time...


At night we explored the dry forest in search for our many targets, but without rain this was a hard and mainly futile task. Especially for frogs it was tough going, as our two main targets Rhinophrynus and Triprion are virtually impossible to find without precipitation. We did see some of the more common species, such as Smilisca baudinii, Leptodactylus melanonotus, Lithobates forreri, Incilius marmoreus and Rhinella horribilis. One evening we were roadcruising on a dusty road when a green blob hopped on the road. We just crossed paths with a Mexican Giant Leaf Frog (Agalychnis dacnicolor) despite the lack of rain. That was lucky! Also snakes were not really active during our time at the coast. Our searches for snakes led us through the dry forests, around agricultural land and past swamps and lagoons behind beaches. On such an occasion we were having dinner on the beach inside a national park, when we saw lights approaching. Based on previous experiences, we suspected it was the police coming for us, as we weren't actually sure it was allowed to be inside the national park at night. To our surprise however the lights turned out to actually belong to people hauling in generators, beer, and sound installations. We asked the guys what they were here for, and they told us that they are the organizers of a rape party, which was about to go down tonight. That raised a few eyebrows indeed, before we realised that "rape" is the Spanish pronunciation of the word "rave". When we also encountered a group of 20 Dutch girls partying on the beach a bit further ahead, we were sure we weren't going to get into trouble with the police tonight. To continue herping was the real challenge now, but we managed to pull ourselves away from the beach and back into the forest. Over the course of four nights we saw some common snake species, such as Indotyphlops braminus, Enulius flavitorques, Imantodes gemmistratus, Leptodeira maculata, Leptodeira nigrofasciata, Trimorphodon biscutatus, and two Mexican Burrowing Pythons (Loxocemus bicolor). Sander also spotted a Central American Milk Snake (Lampropeltis abnorma), but of our highly desired rattlesnakes or cantils, not a trace was to be found. Also some geckos were seen - of course the ubiquitous Hemidactylus frenatus and Phyllodactylus tuberculosus, but also a few Colima Banded Geckos (Coleonyx nemoralis). Noteable mammals included Mexican Mouse Opossum (Marmosa mexicana), Southern Opossum (Didelphis marsupialis) and Raccoon (Procyon lotor).

On the long drive east we made two relatively short stops to look for some very interesting lizards. At the first stop we quickly found the beautiful MacDougall's Spiny Lizard (Sceloporus macdougalli), which has a tiny range. We also spotted several Sceloporus smithi, which had eluded us at earlier attempts. Other species seen were Sceloporus siniferus, Aspidoscelis deppii and Iguana iguana. After a successful morning we arrived at the next location further east. It was already really warm, but we knew where to go. After about an hour of searching, Sander spotted exactly what we came for, and a beautiful Giant Horned Lizard (Phrynosoma asio) was sitting in the leaf litter. It was a joy to see these amazing lizards again!

Chiapas - La Sepultura

22nd until the 24th of August 2023, 26th of August 2023

Late in the afternoon we arrived in the Municipio Jiquipilas. Here we met local biologist and new amigo Emmanuel Javier Vázquez. While we stayed at the only hotel in town, he kindly invited us to have breakfast and dinner at his family home. Here we enjoyed delicious home-cooked meals and the company of cute dog Dotty. We explored the surrounding areas to search for Bolitoglossa flaviventris, which we sadly did not find. A bit of rain would have certainly helped in our search, but even without rain we did get to see a whole range of other species, such as Dendropsophus robertmertensi, Duellmanohyla schmidtorum, Plectrohyla matudai, Ptychohyla macrotympanum, Scinax staufferi, Craugastor rhodopis, Rhinella horribilis, Dermophis mexicanus, Kinosternon abaxillare, Anolis sericeus, Basiliscus vittatus, Corytophanes hernandesii, Oxybelis microphthalmus, Coniophanes fissidens, Imantodes gemmistratus, Leptodeira maculata and Ninia sebae. We also had a close encounter with a Mexican Hairy Dwarf Porcupine (Coendou mexicanus). During the day it was a lot harder to find animals, but we did get to see some species such as Scincella assata, Scincella cherriei, Lepidophyma smithii, Epictia phenops and Lampropeltis abnorma. Emmanuel even surprised us with a Mexican Beaded Lizard (Heloderma horridum), one of our main targets! When we got out of the forest there were three military vehicles and around 20 soldiers waiting for us. They saw our car and wanted to know what we were doing. As Emmanuel luckily could present them with the necessary permits, it wasn't a problem we were there and we could go our way again soon. Thanks a lot for the great time Emmanuel, we will be back for those salamanders! And Dotty.

We herped inside the Reserva de la Biosfera La Sepultura once more a few days later, but much further south at a place we knew well from our previous visit to Mexico. We had hoped to meet herping buddy Arturo here, but sadly it didn't work out. We still herped around some ancient ruins and pyramids situated on top of a hill and got to see several familiar species, such as Craugastor rhodopis, Eleutherodactylus pipilans, Leptodactylus melanonotus, Incilius canaliferus, Hypopachus ustus, Anolis serranoi, Sceloporus siniferus, Coleonyx elegans, Phyllodactylus tuberculosus, Lepidophyma smithii, Leptodeira septentrionalis, Tropidodipsas fasciata and a big, but very ill Common Northern Boa (Boa imperator). Our mammal sightings included Grey Fox (Urocyon cinereoargenteus) and Hooded Skunk (Mephitis macroura).

Chiapas - Reserva Ecológica La Pera

24th until the 26th of August 2023

On our previous trip to Southern Mexico we also visited this nature reserve, but we had missed seeing some special endemic vipers. This time we had much more humid conditions, so we got our hopes up. The frogs were definitely more active during this visit, and at night we could observe several species, such as Smilisca baudinii, Craugastor alfredi, Craugastor lineatus, Craugastor rhodopis, Craugastor stuarti and Incilius valliceps. Especially the Black-eyed Leaf Frogs (Agalychnis moreletii) were more active. Last visit we only spotted them at night sleeping high up in the canopy, now there was a lot of breeding activity going on with calling males, couples in amplexus and depositing eggs. On one such instance I even spotted a Northern Cat-eyed Snake (Leptodeira septentrionalis) in ambush near the frogs. I decided to not disturb the snake and check later what would happen. This turned out to be a good decision, as we could all observe the snake devouring a frog it had just caught! A frog species we missed last time was Crowned Tree Frog (Triprion spinosus), of which we could now find three individuals, with two of them close to each other in the low vegetation. Salamanders were surprisingly less easy to find, but we still saw several Southern Banana Salamanders (Bolitoglossa occidentalis) and a single Alberch's Mushroomtongue Salamander (Bolitoglossa alberchi) juvenile at night. A visit to a special cave we visited last time as well didn't yield any results during the day. However, at night Laura and I found a female and a juvenile Black Jumping Salamander (Ixalotriton niger) at the same location. Reptiles were even harder to come by, and we mostly found some of the more commonly seen species, such as Anolis lemurinus, Imantodes cenchoa, Sibon nebulatus and Ninia diademata. Luckily Sander found a beautiful Sapper's Rustyhead Snake (Amastridium sapperi) and Robin spotted a massive Fer-de-Lance (Bothrops asper) during a foggy evening.

Chiapas - lowlands

27th until the 1st of September 2023

We actually started in the mountains where Laura had arranged a visit to a local community where our main target Bolitoglossa flaviventris should occur. A long drive through some beautiful forested mountains led us to the small community. It turned out that, because of a miscommunication, we didn't have permission as we thought we would have, and we first had to present to the village elders. We told them what we wanted to do and that we were only interested in photographing wildlife. But some were worried we would take gold, while others were worried that people from neighbouring villages might shoot us. One guy also had an opinion ("tengo una opinion!") and thought we would make a lot of money with Youtube videos while they don't earn anything. It became clear this was pointless and we thanked them for their time, drove out of the village and when out of sight, still herped along suitable looking streams. We found several Bolitoglossa occidentalis and calling Plectrohyla matudai. Also some Lithobates maculatus, Geophis nasalis and Sibon nebulatus, but sadly not our desired salamanders.

The southern lowlands of Chiapas are not the easiest place for herping. As we would find out once more...The next day was full of surprises. We thought of doing something relaxing for a change, and maybe pick up some herps along the way. A visit to a beautiful waterfall would be perfect. Of course the moment we arrived there the sky darkened and the heaven's gates opened. Torrential rain came falling down just when we had finally reached the waterfall and entered the water. The river started to rise quickly and we had to make a quick escape to flee from the raging river the stream had turned into. Another day in paradise! In the evening we met up spontaneously with our friend Alondra, who turned out to live opposite of our hotel! A mere coincidence which Robin found out while having a drink with an employee of the hotel. She told us her niece is also interested in amphibians and reptiles, to which Laura and I already thought that that must be Alondra. A small world after all! However, the evening didn't yield any results to show for, and we only found some Hyalinobatrachium viridissimum, Eleutherodactylus pipilans, Ptychohyla euthysanota and Basiliscus vittatus. It was still fun to see each other again and herp together once more!

A few days prior we had made a short stop in a swamp near the coast. Here Laura ran into a couple of Mexican birders. They showed us some pictures of the rarely seen Agami Heron, of which we actually didn't know it occurs in this part of Mexico, so that was a nice surprise! Today we came back with some more knowledge of the place, and arranged a boat trip through the mangroves via EcoHostal Costa Verde. It was pure birding bliss, and immediately we saw highlights such as Giant Wren (Campylorhynchus chiapensis), Ferruginous Pygmy Owl (Glaucidium brasilianum), Anhinga (Anhinga anhinga), Northern Jacana (Jacana spinosa), Northern Potoo (Nyctibius jamaicensis), Mexican Hairy Dwarf Porcupine (Coendou mexicanus), Boat-billed Heron (Cochlearius cochlearius), Bare-throated Tiger Heron (Tigrisoma mexicanum) and finally also the highly desired Agami Heron (Agamia agami). The mangroves were beautiful and it was a great experience to explore them by boat. We also saw some herps, such as Aspidoscelis deppii, Basiliscus vittatus, Ctenosaura similis and Coniophanes fissidens. With help of our guide Pedro we even managed to observe a couple of Chiapas Giant Musk Turtles (Staurotypus salvinii). After searching in vain for crocodilians, we drove to our next accommodation further to the southeast. We got very lucky with the weather as it started to pour down just when we got in the car.

We arrived at our accommodation where we had some excellent pizza. During dinner the rain started to become less. With just a small drizzle falling, we explored the surrounding area on foot. This was our second last chance to find our main target Bolitoglossa flaviventris. Anurans were quick to take advantage of the rain, and we saw many calling Leptodactylus fragilis and Incilius canaliferus. A few hundred meters from our accommodation luck struck like lightning. Laura saw something yellowish glistening in a coffee bush and took a step closer. Then we all heard her all too familiar scream - this must be a salamander... It was hard to believe what we were seeing, finally a Yellowbelly Mushroomtongue Salamander (Bolitoglossa flaviventris)! So they do exist! What an incredible feeling to finally see this species with our own eyes. I don't think we searched more, and invested more preparation, time and energy in a single species. But in this moment, this was all worth it. They were also so much more beautiful than I thought they would be! Apparently the conditions on this evening were just right, since Laura spotted a second individual and Robin even a third one. Incredible! We also saw some Bolitoglossa occidentalis, Anolis dollfusianus and an Armadillo (Dasypus novemcinctus).

The final days we took it a little more easy. We revisited the Finca Argovia, where we were welcomed back like family. We had some amazing food, and herped a bit before and after dinner. We found some of the more common species, such as Craugastor rhodopis, Craugastor rupinius, Lithobates maculatus, Incilius canaliferus, Rhinella horribilis, Leptodeira septentrionalis and Ninia sebae. We also undertook some roadcruising close to the coast where other people have had success with rattlesnakes. We found Leptodeira maculata, Coniophanes fissidens and Enulius flavitorques, but again, no rattlesnakes for us. During the day we made good use of the swimming pool and established new techniques to go down the slide faster. Basically all we could do in this heat!


On a trip with such diversity and so many different species to see, there are equally many (if not more!) species to miss. While we were incredibly successful and found 178 species, including many of our main targets, there is still much we want to come back for. During the first three weeks of the trip, we were in the highlands where we experienced some rain. There we always did well finding our main targets, but missed quite some species we thought we would encounter somewhere along the road. During the final two weeks of the trip, we were in the lowlands where it was the opposite: Our main targets were very hard to find due to the dry conditions, but we did see some other more common species in the process. Well, that is the game, and we are already keen on going back to Mexico! The people are super friendly, and the traveling is in general rather easy. Many people have asked me about the safety situation. Maybe we are lucky and a bit naive, but nowhere during our trip we felt unsafe. Local people warned us against visiting certain areas, and we adhered to their advice. However, in Oaxaca and Chiapas we did notice some changes in comparison to 2019; The coastal highway is lined with refugees from all over Central and South America, trying to make their way to the US. In several towns the pavement was lined with people sleeping there at night and shops closed early. Allegedly, there is also more narco activity in the area nowadays. Moreover, there were many more police checkpoints and a lot more military patrolling the area.  While this all doesn't necessarily make the area unsafe, it does give off a different vibe. Additionally, the habitat destruction is clearly visible in many places. Some locations we visited in order to find forest-dwelling salamanders turned out to be cow pastures nowadays. In most locations where we have seen Abronia, we could see the edge of their forest in every direction. Luckily there are still vast swathes of natural areas left, and we certainly hope it stays that way. In short, herping in Mexico was bliss, the biodiversity is through the roof, and we have much left to see. The only thing we won't miss is the insane amount of speed bumps (topes)!

Make sure to check out Laura's Flickr Albums as well!


Leora's Stream Salamander (Ambystoma (altamirani) leorae)

Mexican Tiger Salamander (Ambystoma velasci)

Coffee Grove Salamander (Aquiloeurycea cafetalera)

Red-legged False Brook Salamander (Aquiloeurycea cephalica)

Alberch's Mushroomtongue Salamander (Bolitoglossa alberchi)

Yellowbelly Mushroomtongue Salamander (Bolitoglossa flaviventris)

Oaxacan Mushroomtongue Salamander (Bolitoglossa macrinii)

Southern Banana Salamander (Bolitoglossa occidentalis)

Broadfoot Mushroomtongue Salamander (Bolitoglossa platydactyla)

Pygmy Splayfoot Salamander (Chiropterotriton lavae)

Common Splayfoot Salamander (Chiropterotriton chiropterus)

Giant False Brook Salamander (Isthmura gigantea)

Cofre de Perote Salamander (Isthmura naucampatepetl)

Black Jumping Salamander (Ixalotriton niger)

Morelos Salamander (Pseudoeurycea altamontana)

Jaguar Salamander (Pseudoeurycea jaguar)

Sierra Juarez Salamander (Pseudoeurycea juarezi)

Leprous False Brook Salamander (Pseudoeurycea leprosa)

Muscular Salamander (Pseudoeurycea papenfussi)

Claw-toothed Salamander (Pseudoeurycea unguidentis)

Boreal Pygmy Salamander (Thorius boreas)

Macdougall's Pygmy Salamander (Thorius macdougalli)

Lower Cerro Pygmy Salamander (Thorius pulmonaris)

Veracruz Pygmy Salamander (Thorius pennatulus)

Mexican Caecilian (Dermophis mexicanus)

Mexican Giant Leaf Frog (Agalychnis dacnicolor)

Black-eyed Leaf Frog (Agalychnis moreletii)

Porthole Tree Frog (Charadrahyla taeniopus)

Merten's Yellow Tree Frog (Dendropsophus robertmertensi)

Schmidt's Mountain Brook Frog (Duellmanohyla schmidtorum)

Puebla Tree Frog (Exerodonta xera) - call only

Mountain Tree Frog (Hyla eximia)

Southern Highland Tree Frog (Hyla euphorbiacea)

Ridged Tree Frog (Hyla plicata)

Matuda's Spikethumb Frog (Plectrohyla matudai)

Cloud Forest Stream Frog (Ptychohyla euthysanota)

Pine Forest Stream Frog (Ptychohyla macrotympanum)

Gloomy Mountain Stream Frog (Ptychohyla zophodes)

Small-eared Tree Frog (Rheohyla miotympanum)

Hazel's Tree Frog (Sarcohyla hazelae)

Stauffer's Long-nosed Treefrog (Scinax staufferi)

Common Mexican Treefrog (Smilisca baudinii)

Crowned Tree Frog (Triprion spinosus)

Alfred's Rainfrog (Craugastor alfredi) 

Adorned Robber Frog (Craugastor decoratus)

Montane Robber Frog (Craugastor lineatus)

Common Leaf-litter Frog (Craugastor loki)

Mexican Robber Frog (Craugastor mexicanus)

Pygmy Robber frog (Craugastor pygmaeus)

Stuart's Rainfrog (Craugastor stuarti)

Polymorphic Robber Frog (Craugastor rhodopis)

Cliffy Stream Frog (Craugastor rupinius)

Rio Grande Chirping Frog (Eleutherodactylus cystignathoides)

Whistling Chirping Frog (Eleutherodactylus pipilans)

Mexican White-lipped Frog (Leptodactylus fragilis)

Sabinal Frog (Leptodactylus melanonotus)

Northern Glassfrog (Hyalinobatrachium viridissimum)

Two-spaded Narrow-mouthed Toad (Hypopachus ustus)

Rio Grande Leopard Frog (Lithobates berlandieri)

Forrer's Grass Frog (Lithobates forreri)

Moore's Frog (Lithobates johni)

Highland Leopard Frog (Lithobates maculatus)

Montezuma Leopard Frog (Lithobates montezumae)

Dwarf Toad (Incilius canaliferus)

Marbled Toad (Incilius marmoreus)

Pine Toad (Incilius occidentalis)

Gulf Coast Toad (Incilius valliceps)

Western Cane Toad (Rhinella horribilis)

Mexican Spadefoot (Spea multiplicata)

Green Sea Turtle (Chelonia mydas)

Olive Ridley Sea Turtle (Lepidochelys olivacea)

Central Chiapas Mud Turtle (Kinosternon abaxillare)

Chiapas Giant Musk Turtle (Staurotypus salvinii)

Green Arboreal Alligator Lizard (Abronia graminea)

Bromeliad Arboreal Alligator Lizard (Abronia taeniata)

Transvolcanic Alligator Lizard (Barisia imbricata)

Sierra Juárez Alligator Lizard (Mesaspis juarezi)

Mexican Beaded Lizard (Heloderma horridum)

Coffee Anole (Anolis dollfusianus)

White Anole (Anolis laeviventris)

Ghost Anole (Anolis lemurinus)

Clouded Anole (Anolis nebulosus)

Oaxacan Oak Anole (Anolis quercorum)

Brown Anole (Anolis sagrei)

Schiede's Anole (Anolis schiedii)

Silky Anole (Anolis sericeus)

Ahuachapán Anole (Anolis serranoi)

Greater Scaly Anole (Anolis tropidonotus)

Moist Forest Anole (Anolis unilobatus)

Zapotec Anole (Anolis zapotecorum)

Western Mexican Whiptail (Aspidoscelis costatus)

Blackbelly Racerunner (Aspidoscelis deppii)

Spotted Whiptail (Aspidoscelis gularis)

Brown Basilisk (Basiliscus vittatus)

Hernandez's Helmeted Basilisk (Corytophanes hernandesii)

Western Spiny-tailed Iguana (Ctenosaura pectinata)

Black Spiny-tailed Iguana (Ctenosaura similis)

Rainbow Ameiva (Holcosus undulatus)

Green Iguana (Iguana iguana)

Giant Horned Lizard (Phrynosoma asio)

Mexican Plateau Horned Lizard (Phrynosoma orbiculare)

Black-bellied Bunchgrass Lizard (Sceloporus aeneus)

Anahuacan Bunchgrass Lizard (Sceloporus anahuacus)

Southern Crevice Spiny Lizard (Sceloporus aureolus)

Transvolcanic Bunchgrass Lizard (Sceloporus bicanthalis)

Mexican Emerald Spiny Lizard (Sceloporus formosus)

Graphic Spiny Lizard (Sceloporus grammicus)

MacDougall's Spiny Lizard (Sceloporus macdougalli)

Largescale Spiny Lizard (Sceloporus megalepidurus)

Central Cleft Lizard (Sceloporus mucronatus)

Longtail Spiny Lizard (Sceloporus siniferus)

Smith's Rosebelly Lizard (Sceloporus smithi)

Eastern Spiny Lizard (Sceloporus spinosus)

Crevice Swift (Sceloporus torquatus)

Rosebelly Spiny Lizard (Sceloporus variabilis)

Tropical Tree Lizard (Urosaurus bicarinatus)

Yucatán Banded Gecko (Coleonyx elegans)

Colima Banded Gecko (Coleonyx nemoralis)

Yellowbelly Leaf-toed Gecko (Phyllodactylus tuberculosus)

Common House Gecko (Hemidactylus frenatus)

Shortnose Skink (Plestiodon brevirostris)

Cope's Skink (Plestiodon copei)

Red Forest Skink (Scincella assata)

Brown Forest Skink (Scincella cherriei)

Forest Ground Skink (Scincella gemmingeri)

Huaxteca Lesser Galliwasp (Siderolampus enneagrammus)

Smith's Tropical Night Lizard (Lepidophyma smithii)

Knob-scaled Lizard (Xenosaurus grandis)

Common Northern Boa (Boa imperator)

Oaxacan Dwarf Boa (Exiliboa placata)

Mexican Burrowing Python (Loxocemus bicolor)

Yellow-snouted Threadsnake (Epictia phenops)

Flowerpot Snake (Indotyphlops braminus)

Spotted Earthsnake (Conopsis acuta)

Lined Earthsnake (Conopsis lineata)

Central American Milk Snake (Lampropeltis abnorma)

Thornscrub Vine Snake (Oxybelis microphthalmus)

Mexican Bull Snake (Pituophis deppei)

Bocourt's Black-headed Snake (Tantilla bocourti)

Yellow-lined Centipede Snake (Tantilla flavilineata)

Red Black-headed Snake (Tantilla rubra)

Lesser Centipede Snake (Tantilla schistosa)

Western Lyre Snake (Trimorphodon biscutatus)

Sapper's Rustyhead Snake (Amastridium sapperi)

Liebmann's Earth Runner (Chersodromus liebmanni)

Yellow-bellied Snake (Coniophanes fissidens)

Pacific Longtail Snake (Enulius flavitorques)

Mesa del Sur Earthsnake (Geophis dubius)

Duellman's Earthsnake (Geophis duellmani)

Loranca's Earth Snake (Geophis lorancai)

Highland Earth Snake (Geophis multitorques)

Coffee Earth Snake (Geophis nasalis)

Broken-ringed Earth Snake (Geophis semidoliatus)

Common Blunt-headed Tree Snake (Imantodes cenchoa)

Central American Blunt-headed Tree Snake (Imantodes gemmistratus)

Southwestern Cat-eyed Snake (Leptodeira maculata)

Black-banded Cat-eyed Snake (Leptodeira nigrofasciata)

Northern Cat-eyed Snake (Leptodeira septentrionalis)

Ringneck Coffee Snake (Ninia diademata)

Redback Coffee Snake (Ninia sebae)

Oaxacan Graceful Brown Snake (Rhadinaea bogertorum)

Forbes's Graceful Brown Snake (Rhadinaea forbesi)

Cloudy Snail-eating Snake (Sibon nebulatus)

Banded Snail Sucker (Tropidodipsas fasciata)

Golden-headed Garter Snake (Thamnophis chrysocephalus)

Conant's Garter Snake (Thamnophis conanti)

Liner's Garter Snake (Thamnophis lineri)

Long-tailed Alpine Garter Snake (Thamnophis scalaris)

Yellow-bellied Sea Snake (Hydrophis platurus)

Fer-de-Lance (Bothrops asper)

Mexican Smallheaded Rattlesnake (Crotalus intermedius)

Mexican Lanceheaded Rattlesnake (Crotalus polystictus)

Mexican Pygmy Rattlesnake (Crotalus ravus)

Huamantlan Rattlesnake (Crotalus scutulatus ssp. salvini)

Dusky Rattlesnake (Crotalus triseriatus)

Mexican Jumping Pitviper (Metlapilcoatlus nummifer)

Black-tailed Horned Pitviper (Mixcoatlus melanurus)

Mexican Horned Pitviper (Ophryacus undulatus)

Many thanks to Aarón Arias, Matthieu Berroneau, Tim Burkhardt, Justin Elden, Romeo García Cortes, Bruno & Nick Giesemann, Arnaud Jamin, Emmanuel Javier Vázquez, Emanuel Jelsch, Myles Masterson,  Joachim Nerz, Alondra Rojas, Sean Rovito, René Villanueva Maldonado, Vojtech Vita, Sebastian Voitel, Tim Warfel & Britt White.