Herpetological trip to the Yucatan Peninsula (Mexico)
October 27th – November 3rd 2018

List of observed species

Unless specified otherwise, all pictures (c) of Jeroen Speybroeck.

A short escape to paradise brought Wouter, Jesse en me to Mexico. The rainy season was over, so we tried to maintain realistic expectations, whatever those may be in an area you have never been too.

October 27th

Jesse was waiting for us with the rental car ready, as Wouter and I hit Mexican soil in Cancun. Temperature was about 20 degrees Celcius higher than what we had when leaving Amsterdam, so that was a change… It was already dark when we drove to our first stay – Case Selva Orquideas, Tulum. Short stops along the drive there offered some sleeping Anolis ustus and some DOR snakes (a heart breaking 3 Boa imperator, a Micrurus diastema and an Oxybelis aeneus). Hemidactylus turcicus and H. frenatus were soon spotted at a roadside shop and near most lamp lights. Dendropsophus microcephalus and Scinax staufferi were seen but not photographed yet (as they would remain until the end of the trip, unfortunately). The omnipresent Lithobates brownorum also hopped across the road a few times.

October 28th

After breakfast we went out to explore the wider area around Coba, with its woods and lagunas. This would be our playground for the first lap of the trip. A big dark snake fled off the road, which must have been Drymarchon melanurus. Also a fresh DOR Mastigodryas melanolomus and a DOR Tropidodipsas sartorii. A cistern with shallow water delivered, with a small Crocodylus moreletii, Incilius valliceps, Smilisca baudinii and Lithobates brownorum. A little strawl to the nearby laguna had us finding Sphaerodactylus glaucus, Aspidosceles angusticeps, Basiliscus vittatus and Sceloporus chrysostictus. A female Ctenosaura similis fled into a wall but we could get it out for a closer encounter.

road banks with rich vegetation – animals can pop in and out at any time

catch of the day - © Wouter Beukema

Morelet’s Crocodile Crocodylus moreletii

Morelet’s Crocodile Crocodylus moreletii

Smilisca baudinii – a common, somewhat larger tree frog species

Incillius valliceps

Ctenosaura similis - © Wouter Beukema

shy Aspidosceles angusticeps - © Wouter Beukema

By nighttime, it seemed that the area we wanted to explore had received some rain. This helped - finally some living snakes to put our hands on, with Leptodeira septentrionalis, Sibon sanniolus, Dipsas brevifacies (which wasn’t identified as such until several hours later) and Tropidodipsas sartorii. The latter would turn out to be the trip’s most commonly encountered snake species, both dead and alive. Also a first (but definitely not last) DOR Bothrops asper and Ninia sebae. Wouter was fortunate to spot a Laemanctus serratus high up in a tree. Notable anuran additions were Trachycephalus typhonius (do not rub your eyes or pick your nose after holding this species!) and Agalychnis callidryas. Our first Rhinella horribilis was a DOR – we didn’t see all that many specimens of this species and somehow it also went unphotographed. A subadult of the endemic partially cave-dwelling Craugastor yucatanensis hopped across the road when we were driving out.

Trachycephalus typhonius

Agalychnis callidryas

Anolis ustus - © Wouter Beukema

Lithobates brownorum - © Wouter Beukema

Craugastor yucatanensis

Tropidodipsas sartorii

Tropidodipsas sartorii

Tropidodipsas sartorii

Leptodeira septentrionalis

Leptodeira septentrionalis

Sibon sannolius

Dipsas brevifacies

A great day that showed us that the season was not entirely slow just yet.

October 29th

A little trail looked tempting and gave our first Anolis rodriguezii. A wasp attack later, we switch to the banks of a Coba laguna, and caught a Thamnophis proximus. Late afternoon, we dove into a cave and found two Craugastor and Lithobates in there.

our first stay – the excellent Casa Selva Orquideas

Jesse and jungle

jungle and me – © Jesse Erens

lunchtime!

spot the iguana

garter snake photography

Thamnophis proximus

Anolis sagrei

Anolis rodriguezii – © Wouter Beukema

Anolis rodriguezii – © Jesse Erens

cave entrance – © Wouter Beukema

Craugastor yucatanensis

At dusk, we were sad to pick up Oxybelis fulgidus and Leptophis ahaetulla casualties from the road. Next, a very swift and agile Micrurus got away. This was the start of a frustrating night, with a live Leptodeira septentrionalis and Tropidodipsas sartorii, but with DORs of Coleonyx elegans, Coniophanes schmidti (3) and Senticolis triaspis. Luckily, still some frogs to enjoy, among which both Tlalocohyla loquax and T. picta.

Agalychnis callidryas

Tlalocohyla loquax

October 30th

On to the second chapter, which we expected to be wetter and better.

We drove all the way south to stay near Xpujil. A short break in between at Sian Ka’an had Scincella cherriei as the only addition to our species list.

Basiliscus vittatus

Sceloporus chrysosticus - © Wouter Beukema

After checking in to our cabana, we cruised a first night, but it turned out to be rather dry, finding an ocelot, Tropidodipsas sartorii, and DORs of Coniophanes imperialis and Ninia sebae.

October 31st

We drive the 60 km through the jungle to the ancient Mayan ruins of Calakmul. The low level of tourism at this marvel was a very welcome surprise to us. Some stops along the road allowed for lazy herping and delivered Anolis tropidonotus, some more crocs, Holcosus hartwegi and more. We climbed up to the top of the highest Calakmul structure. Stunning views of the jungle canopy all around, as far as the eye can see… A bit of rain started and got the local spider and howler monkeys particularly active. We drove back out and saw some weird forest turkey and an agouti.

healthy breakfast at Rio Bec

spotted at least 6 crocs in this small pond

colourful forest fowl

Anolis tropidonotus - © Wouter Beukema

Holcosus hartwegi - © Wouter Beukema

I am not strong on cultural outings, but this was jaw dropping - Calakmul

spider monkey with Michael Jackson baby

spider monkey

howler monkey

The night drive was pretty humid. First, we finally were able to grab a Coleonyx elegans. In a short stretch of one or two kilometres, we struck gold. Plenty of Smilisca baudinii and Tlalocohyla loquax, but than a much anticipated Triprion petasatus! If that was not already enough, a flat jellyfish circle-shaped blob on the road turned out to be Rhinophrynus dorsalis, a species we had not dared to hope for. Also several cute Hypopachus variolosus. Snakewise, not much fun to be had, with DORs of Tropidodipsas fasciata, Leptodeira septentrionalis, Pseudelaphe flavirufa and Bothrops asper, if it wasn’t for a big fat Boa imperator crawling on the road in the rain.

Rhinophrynus makes people smile!

Rhinophrynus dorsalis

Rhinophrynus dorsalis

Rhinophrynus dorsalis

Rhinophrynus dorsalis

Hypopachus variolosus

Hypopachus variolosus

Smilisca baudinii - a rare green individual

Smilisca baudinii

Tlalocohyla loquax

Triprion petasatus - © Jesse Erens

Coleonyx elegans

time for some boa photography

Boa imperator

Boa imperator

Despite limited snake success, this surely was the best day of the trip.

November 1st

We did the first 20 km of the Calakmul road again, finding the same species and a coati.

there's people who would be afraid of staring into a 20m drop of a pungent bat guano cave and there's Jesse - © Wouter Beukema

Sphaerodactylus glaucus - © Wouter Beukema

This night was going to be rather dry, so we didn’t expect much. Wrong we were, because temperatures stayed at 25°C rather than dropping to 22°C as on most other nights, and air pressure and humidity seemed to be in our favour. First, a wounded Bothrops youngster. Then, Wouter and Jesse hiked a trail on foot and I went on cruising the roads. I could find four snakes. Maybe people staying in for Dia de los Muertos did not hurt, because this was blissfully calm cruising. A subadult boa, and live specimens of three common species – Bothrops asper, Ninia sebae and Tropidodipsas sartorii. In the mean time, Wouter and Jesse hiked a Micrurus diastema and a juvenile Imantodes tenuissimus.

into the night

boa n° 2

Boa imperator

Boa imperator

Micrurus diastema

Imantodes tenuissimus

Imantodes tenuissimus

Imantodes tenuissimus

Bothrops asper

Bothrops asper

An unexpected, good snake result!

A pond in a quarry had some Kinosternon scorpioides cruentatum with pretty faces.

November 2nd

Our final day. For a week, heavy rain had been predicted for this day and night. Unfortunately, it did not hit the area where we wanted to find some more Triprion and perhaps a Pseudelaphe. During the day, we hiked a little trail behind our cabana. Dark clouds were setting, so we hit our nighttime target area early. Good choice, as it delivered a beautiful baby Drymobius margaritiferus. Live snakes later on were limited to Sibon sanniolus and Ninia sebae, plus DORs of Tropidodipsas sartorii and Bothrops asper. We did long distances but the rain hadn’t hit to right places and temperatures dropped to 22°C again. A final memorable stop was made at a temporal pond with Lithobates vaillanti , Trachemys venusta and Kinosternon acutum.

habitat of last night’s terrapins – © Wouter Beukema

Leptodactylus fragilis – © Wouter Beukema

Drymobius margaritiferus

Coleonyx elegans

storm's coming

terrapin time! – © Jesse Erens

Kinosternon acutum – © Wouter Beukema

Trachemys venusta – © Wouter Beukema

Lithobates brownorum - © Wouter Beukema

small road crossing snake at midnight before we collapsed and called it a night - Ninia sebae