A Herpetological Bounty in the Highlands of Hidalgo, Mexico
By Carl J. Franklin
The following account is the first part of a brief collecting episode into Mexico’s Sierra Madre Oriental that took place in December 2004.
As we ascended the sinuous roadway, clouds wisped their way across our path only occasionally providing a glimpse of the surrounding forest. At a moderate elevation of only 1400-1500 meters we were already surrounded by giant tree ferns, cycads, bromeliads, orchids, and a host of other lush vegetation commonly associated with cloud forest. “We” consisted of me, Dr. Eric N. Smith, Luis M. Canseco, Uri Garcia, and ***** ******. Our location was the town of Tlanchinol located in the cloud forest of Hidalgo in central Mexico and we were there collecting amphibians and reptiles as part of an on going survey of Mexican herpetofauna. The survey was a joint effort between the Amphibian and Reptile Diversity Research Center at the University of Texas at Arlington (UTA) and the investigators from the Museo de Zoologia "Alfonso L. Herera" Universidad Nacional Autonoma de Mexico (UNAM).
To date the survey has resulted in the discovery of several new species of amphibians and repiles, but many of the parasites associated with those organisms as well. Not to mention, several publications regarding various aspects of natural history as well as a wealth materials used in the pursuit of numerous masters degrees and doctoral dissertations.
It didn’t take long before a herpetological quarry was reached. Trudging through dense accumulations of leaf litter caused several Polymorphic robber frogs (Eleutherodactylus rhodopis) to jump and reveal their presence. This small species of frog is highly variable with individuals ranging from peach, tan, brown, to those mottled in smatterings of gray, brown, black and white. Due to their cryptic coloration, the presence of these anurans was only realized after they had jumped. Turning moist logs also allowed us the chance to collect snakes. Turning the decaying and moist logs in the cloud forest provided us with the opportunity to find three small and secretive forest dwelling snakes, Stoeria dekayi, Stoeria hidalgoensis, and Rhadinea marcellae. Nearby I could hear flowing water and I wasted no time getting to the source of the noise. Moss covered boulders stood out from the clear waters of the forest stream and I started at once inspecting the gravel bed and areas near the base of the boulders for tadpoles. Before too long, my efforts paid off and I was able to collect a series of tadpoles of the port-hole tree frog (Hyla taeniopus). We continued our searches into the forest until we reached an area that had been completely cut down and cleared for cattle and electrical towers. In one year, a forest that took eons to evolve was reduced to a barren field. All that was left of the forest were occasional logs and stumps. Despite the loss of the forest we continued our search for specimens around and under the remaining logs. It didn’t take long at all before another species of snake was found, Sumichrast’s garter snake (Thamnophis sumichrasti). We initially thought that two species of garter snakes were found. However, this is a species that demonstrates considerable polychromatic variation; one of the specimens we collected was covered in a checkerboard pattern while the other displayed a pattern of brown cross-bars. Before too long our stomachs were growling and eating was the new objective. We headed out to a roadside comeodor that was situated on the edge of the forest. Following he meal, I headed outside in search of additional specimens. Turning rocks revealed several more polymorphic robber frogs. As the sun was setting I hastened my search as I continued to flip small rocks. Soon Eric decided to join me in my post meal search. We were searching the rocks together when I heard a triumphant “AH-HA”. With a grin on his face he carefully uncurled his clenched fist and revealed a small gray false book salamander (Pseudoeurycea sp). As it turned out this not only represented a new species of false-brook salamander, but was only the second specimen of this type to ever have been collected!
Now with our bellies full, excitement high, and caffeine pumping through our nervous systems we began our nocturnal foray in the cloud forest we had explored earlier in the day. My hopes were high for finding Mexican horned pitvipers (Ophryacus undulatus), but despite all of my careful searches all that was found were adult port-hole tree frogs. After an hour we left the cloud forest and began slowly driving back towards town. Of course we were driving slowly and between small rain showers our windows were down as we listened for anuran vocalizations. Before too long we hit pay dirt. From a bank of tree ferns extending from a road cut we collected a series of small-eared tree frogs (Hyla miotympanum).
Nearby, a seep trickled from the top of a road cut and the sound of the slowly dripping cascade beckoned us to investigate. A small “peep” was heard emanating from the rocks and before too long we located the source a small frog belonging to the genus Eleutherodactylus. Further examination of this specimen may reveal that another species was discovered. However, the frog was not all we would find at this location. A stand of tall elephant ears crowded the pool formed by the seep. However, their stalks yielded to a swing of Eric’s machete. Soon I heard his (now trademark) “AH-HA!” All of us gathered around him as he once again slowly uncurled each finger in his closed hand to reveal a new species of Splay-footed salamander (Chiropterotriton sp.) found curled inside the axils of the elephant ear. Another new species had been found! This of course ignited any waning enthusiasm and we all regained a new sense of vigor. Several minutes later a Hidalgo anole (Norops naufragus) was found sleeping on a slender branch. This species of endemic anole was discovered by Jonathan A. Campbell in the 1980s.
Just as we were about to retire for the evening the local police force arrived. After all, there’s not much discretion involved when a group of herpetologist is pulled over on the side of the road and searching road cuts with flashlights. With their machine guns at the ready, a soft spoken officer in charge inquired about our activities.
After showing our permits, passports, etc it was obvious that his curiosity had been piqued. “Do you have any of the little animals with you?” he asked, “Certainly” we replied and we began to show him the lizard, frog and salamander. Then he offered a warning that the salamander was extremely dangerous and we should be very careful when handling it. However, he said we were not in too much danger because we are men. Unable to understand his reasoning for the caution we asked “what are you talking about?” Then he explained how the tiny salamanders supposedly crawl into the vaginas of sleeping women whereupon they inflict unspeakable distress. This resulted in peals of laughter from all of us (even some guffaws) and we explained that such stories (which can be common in many areas of Latin America) are untrue and the tiny amphibian poses no threat to humankind. Soon we bid the police farewell and headed to a hotel for some much needed rest.
The following morning we made plans to visit another patch of cloud forest before visiting some lower elevation localities. With all of us loaded into the van we precariously ascended the narrow unpaved road. Glimpsing over the edge revealed a precipice that was breathtaking to say the least. We marveled at the giant tree ferns, some of which were more than 30 feet tall. Sadly many of these cloud forest giants have been felled in the name of progress. Before too long we encountered a road crew carving a new road through the forest with bulldozers. In the path of the earth moving machines were not only tree ferns, but other interesting flora including cycads! Such the price for progress! While witnessing the removal of virgin forest for a roadway is sad it underscored the reason why we were there and we soon found an isolated area in the forest and began our search. Careful examination of bromeliad and elephant ear axils revealed nothing more than a few additional port-hole tree frogs and leaf litter searches provided more polymorphic robber frogs. However, Uri and Fernando found something else. From beneath a moist and rotten log the two had found a strange looking salamander as well as a specimen of the big-headed false brook salamander (Pseudoeurycea cephalica). However, the weird looking caudate was another false brook salamander of the genus Pseudoeurycea. Presumably the specimen was a male as it possessed two enlarged premaxillary teeth that are used by many salamanders of this family during their courtship activities.
As luck would have it, another new species was discovered. Thus bringing the total of new salamanders to 3 in little more than 24 hours! We soon bid farewell to the forest near Tlanchinol and continued to our next destination. As we approached our next stop I couldn’t help but wonder what other new species were awaiting discovery? How many will slip into extinction without ever being discovered? Habitat loss is the biggest threat these species face in their otherwise pristine montane ecosystem. Fortunately, we had secured a series of voucher specimens and tissues for molecular evaluation that can be used by future generations of investigators to better understand this special herpetological community.
Author’s note: Collecting amphibians and reptiles in Mexico is prohibited without official permits issued by the government.