Coahuila, Mexico 2007


Clouds add a dramatic touch to an already interesting Chihuahuan desert scene in Coahuila, Mexico approximately 1300 meters in elevation (above left)  Encountering species such as the rough green snake (Opheodrys aestivus) (above right) which are typically encountered in wetter localities in eastern Mexico and the United States are exciting finds in desert regions that typically receive very little rainfall.



The bright red coach whip (Masticophis flagellum) is a conspicuous denizen of the desert that spends the days seeking out its prey which often includes grasshoppers, lizards, small birds and rodents.  This specimen was just over 5 feet in length.  This species is non venomous and commonly seen crossing roads during the day (above left).  Baird's rat snake (Pantherophis bairdi) is a nocturnal hunter of sleeping lizards and rodents (above right).


              Southwestern earless lizards (Cophosaurus texanus scitulus) (above) were frequently seen but seldom caught as they quickly darted across the desert terrain, under brush, cacti and rocks.


                                               Crevice spiny lizards (Sceloporus poinsettii) (above) were often collected at night while they were sleeping beneath rocks and within crevices



                  Detected by the vigilant hearing of Robert Makowsky, this mottled rock rattlesnake (Crotalus lepidus lepidus) (above) alerted Robert to its presence by the buzzing of its rattle.



Small snakes such as this ground snake (Sonora semiannulata) were discovered after searching beneath rocks.  This small snake is harmless to humans but possesses a mild venom used to subdue its prey which consist of small insects, spiders and centipedes.


                                     Robert also found this handsome specimen of a western diamondback rattlesnake (Crotalus atrox) as the collecting party explored another site.



Not to be outdone by Robert's success in finding rattlesnakes, Jeff Streicher spotted this vibrant example of a ground snake (Sonora semiannulatta).  Its color greatly contrasted against the pale limestone substrate.



       Southern leopard frogs (Rana berlandieri) were commonly encountered in and near sources of permanent water including rivers, streams, ponds and windmills.  The tadpole can be seen in the photo at the left and an adult specimen is featured at the right. 



   Texas banded geckos (Coleonyx brevis) were commonly encountered when looking under rocks and debris in the desert.  Featured here is a female specimen from east of Cuatrocienegas, Mexico.



The guttural call of amorous Couch's spade footed toads (Scaphiopus couchii) were often heard emanating from temporary desert pools formed by the sudden heavy rains.  This species takes advantage of what little water may appear in the desert and is an explosive breeder with tadpoles adapted for rapid metamorphosis.


                                                                             Checkered gartersnakes (Thamnophis marcianus) were found at night hunting their prey of frogs and lizards



This old red-eared slider (Trachemys scripta elegans) displays the typical coloration of a mature specimen with increasing amounts of melanin.  The overall coloration fades from green to horn-yellow-to almost black.  Also the characteristic red "ears" lose much of their brilliance with advanced age.


Due to an unseasonably wet summer many of the desert plants were in bloom which of course was not objected by any of the Texas tortoises (Gopherus berlandieri) we encountered during our survey.



                                                                     During the course of turning rocks several interesting invertebrates were encountered such as this amblypigid.




                                                                                      Non-venomous yet menacing in appearance ,this solphugid was another interesting find



                                                       Due to the recent rainfall much of the desert flora was in full bloom, lush and green (notice the resurrection ferns in the fore-ground)



     Higher elevations received more cloud contact which in turn provided considerable amounts of moisture to the already wet desert.  This location is approximately 55 miles due south of Big Bend National Forest.



                                                                 This short lined skink (Plestiodon tetragrammus) was found underneath the rotting remains of a fallen yucca.



                                                                          Ground skinks (Scincella lateralis) were found only in the moist valley in and near the town of Muzquiz.



                                         Narrow mouth toads (Gastrophryne olivacea) were commonly found under rocks by day while amorous males were heard vocalizing for females at night.


                                                                                                The night snake (Hypsiglema torquata) is a secretive species that primarily consumes lizards



                                                                             The reflective eyes of the wolf spiders revealed their presence during our nocturnal forays.



                                                                The state of Coahuila is also home to one of the world's most unique ecosystems located in the town of Cuatrocienegas




                                                       Although ecologically unique in a number of ways, the endemic box turtles found only here add an undeniable sense of charisma



                                                    Cienega is the Spanish word for marsh.  These beautiful pools provide a stark contrast to the surrounding desert landscape.




                                                                     A bright eyed juvenile Coahuilan box turtle (Terrapene coahuilae) stares curiously  into the camera lens.



Coahuilan box turtles are the most aquatic of all the North American box turtles and are protected under Mexican law.  This species has been bred numerous times in captivity by several zoological institutions.  Featured here is an adult male.



Despite the bright and gaudy coloration of the coach whip (Masticophis flagellum) this species is alert, fast moving and highly successful as a predator of several animals including grasshoppers, lizards, rodents and small birds.



During our stay in Muzquiz we were fortunate to experience the friendliness and generosity of the people there that helped make our visit a memorable experience.  Our activities caught the attention of the local media and we even provided an hour long television spot regarding the herpetofauna of the area.  (front row L to R) Alejandro Garza, Edmund Brodie, Jonathan Campbell, and the television anchor (whose name I regrettably cannot recall).  (back row L to R) Jeffery Streicher, Elizabeth Martinez Salazar, Toni Arizmendi,Robert Makowsky, Carl Franklin, and Elisa Cabrerra.

Elizabeth, Toni and Elisa are parasitologist that have joined up on several of our Mexican expeditions and have documented several new species of parasites from specimens collected.  Alejandro Garza generously allowed us the opportunity to visit and collect specimens from his property near Muzquiz.

30 species of amphibians and reptiles were collected during the 2007 Coahuila expedition.  Data and specimens gathered from this field study will be utilized for further herpetological studies.



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