David Lazcano

• Doctor of Philosophy
• Head of Department at Unversidad Autonoma de Nuevo Leon

The energy that lizards and snakes invest in reproduction can vary according to their life history strategies and may be reflected in the variation of the number of offspring born, their dimensions, and changes in the weight of reproductive females. We determined the reproductive effort of a female Metlapilcoatlus olmec, which gave birth to a total...

We present the first photographic evidence of amplexus under natural conditions in the field for Triprion spinosus in Mexico.

We present an up-to-date list of the rattlesnakes of México

Geophis dugesii is a dipsadid snake species endemic to Mexico, and distributed throughout the Sierra Madre Occidental to west-central Mexico (Lemos-Espinal and Smith, 2007; 2009; Lemos-Espinal et al., 2015; Heimes, 2016) in the states of Aguascalientes, Chihuahua, Durango, Guanajuato, Jalisco, Michoacán, Nayarit, Sinaloa, and Zacatecas. These snake...

Abstract We report predation by a Desert Kingsnake (Lampropeltis splendida) on a Gophersnake (Pituophis catenifer) in the municipality of Mina, Nuevo Léon, Mexico. The event was discovered during a night survey in the area looking for live and DOR specimens

We document predation on a Mojave Rattlesnake (Crotalus scutulatus) by a Coachwhip (Masticophis flagellum) in a walnut plantation in the municipality of Hidalgo del Parral, Chihuahua, Mexico. Resumen Aquí documentamos la depredación de una serpiente de cascabel de Mojave (Crotalus scutulatus) por parte de un chirrionera (Masticophis flagellum) en u...

The species of rattlesnakes that inhabit the islands of the Gulf of California in México represent a group of vertebrates that are endangered (García-Padilla et al., 2018). The main pressures they face are invasive species and illegal capture for commercialization (Mellinck, 1995). Presently, aspects of natural history and conservation status for m...

In the course of sampling herpetofauna on 21 May 2023, we found a Northern Sheep Frog (Hypopachus variolosus) with a lack of pigment in the skin (albino). This discovery represents the first documented case of albinism in this species for the state and country.

We documented anecdotic and photographically the presence of Crotalus morulus in the Mexican state of Tamaulipas, as well as the species of the herpetofauna associated with the habitat of this emblematic species of pitviper in a couple of localities in southern Tamaulipas. We observed several serious environmental issues in both of the study areas....

We present a list of amphibian and reptile species from the locality known as Sierra de Tesistán, which is located in the municipality of Zapopan in the Mexican state of Jalisco. After four years of sampling, 65 species are recorded, of which 18 are amphibians and 47 are reptiles. Ten amphibians and 28 reptiles are endemic to Mexico; four amphibian...

While sampling herpetofauna in the Chamela-Cuixmala Biosphere Reserve, we observed predation on an adult Western Spiny-tailed iguana (Ctenosaura pectinata) by a White-nosed Coati (Nasua narica). Resumen En un muestreo de herpetofauna realizado en la reserva de la Biosfera Chamela-Cuixmala, observamos la depredación de un individuo adulto de iguana...

Chiapas harbors significant biological and cultural diversity. The region known as Selva Lacandona is an ideal example to study what is called the “biocultural axiom”. This neotropical region is inhabited by multiple indigenous groups, such as the Tsotziles, Tseltales, Tojolabales, Ch’oles, Kanjobales, Chujes, Mames, Lacandones (Hach Winik), and Zo...

Resumen.-Las interacciones depredador-presa en la naturaleza son escasamente observadas y foto documentadas. Este tipo de información de historia natural es vital para comprender la cadena trófica y la ecología de las especies involucradas. Presentamos nueva información relevante sobre la dieta de la Mazacuata (Boa imperator) en la porción norte de...

We document reports of Ophisaurus incomptus from the state of Tamaulipas, Mexico. This is one of the rarest lizards found in northeastern Mexico. There are some general data from the sites where they were reported, but we know that there is much that is unknown about this species.

In this document we report predation by the Texas patch-nosed snake (Salvadora lineata) on the Texas alligator lizard (Gerrhonotus infernalis) in the state of Coahuila, Mexico. In addition, we describe certain aspects related to the biology of each species and provide a brief description of the study site. Resumen En este documento reportamos la de...

In this work we update the species of amphibians and reptiles known to “El Diente,” which is the most visited zone by tourists inside the Natural Protected Area in Bosque El Nixticuil-San Esteban-El Diente (Bensedi). The species documented here result from five years of casual encounters and directed surveys. The authors’ personal observations have...

Reptiles have various predator defense techniques (antipredation strategies), including size, spines, and other morphological modifications or ornaments, as well as autotomization, that is the voluntary release of the tail so that it serves as a decoy, allowing the lizard to flee from its predators. Losing a limb might also be part of this antipred...

The Amphibians and Reptiles of the Los Chimalapas Region, Isthmus of Tehuantepec, Oaxaca, Mexico: Composition, Distributional Categorization, Conservation Status, and Biodiversity Significance Please read, download and share https://biologiaysociedad.uanl.mx/.../b/article/view/73/63

Dado el incesante impulso de la actual crisis mundial de la biodiversidad, existe una gran urgencia en documentar y reportar la ocurrencia y distribución de especies, y las amenazas para su persistencia. Esta urgencia aumenta aún más cuando se trata de especies secretivas de regiones poco estudiadas. Presentamos una lista taxonómica actualizada de...

Abstract We present a list of amphibian and reptile species from the locality known as Palo Gordo inthe municipality of Zapopan. After one year of sampling, 55 species were recorded, of which17 are amphibians and 38 are reptiles. Resumen Presentamos un listado de especies de anfibios y reptiles de la localidad conocida como PaloGordo en el municipi...

New record of the interaction between the monogenetic fluke Polystoma naevius (Monogenea: Polystomatidae) found in the urinary bladder of Smilisca baudinii (Anura: Hylidae) in Tamaulipas, Mexico

Oaxaca es el estado de México con mayor diversidad biológica y cultural. Los pueblos originarios de Oaxaca son todos descendientes, total o parcialmente, de la antigua cultura madre Olmeca también conocida como “Pueblo del Jaguar”. Estos pueblos originarios actualmente están tratando de defender sus territorios y bienes naturales comunes de la expl...

Este artículo compila información sobre diferentes aspectos de la biología de la cascabel diamantada occidental (Crotalus atrox), un crótalo norteamericano que puede encontrarse en EE. UU. y México. Específicamente, este artículo trata sobre su descripción morfológica, historia taxonómica, hábitat, comportamiento, dieta, reproducción, veneno y cons...

The distribution of Trimorphodon tau Cope, 1869 in Nuevo León, Mexico, is understood on the basis of only a few records from the municipality of Iturbide and the central portion in the municipality of Monterrey, both in the southern portion of the state. The most recent record was reported in 2020. We provide new information on specimens from the c...

Genomic data continue to advance our understanding of species limits and biogeographic patterns. However, there is still no consensus regarding appropriate methods of phylogenomic analysis that make the best use of these heterogeneous data sets. In this study, we used thousands of ultraconserved element (UCE) loci from alligator lizards in the genu...

Genomic data continue to advance our understanding of species limits and biogeographic patterns. However, there is still no consensus regarding appropriate methods of phylogenomic analysis that make the best use of these heterogeneous data sets. In this study, we used thousands of ultraconserved element (UCE) loci from alligator lizards in the genu...

During a field trip in February 2020 to Bosque de “La Primavera” in the state of Jalisco, Mexico, we observed a Colima Giant Whiptail (Aspidoscelis communis) being preyed upon by a Thornscrub Vine Snake (Oxybelis microphthalmus). Although these species are sympatric throughout much of their distributions in Mexico, due to the arboreal habits of O....

We report predation by the Central American Indigo Snake (Drymarchon melanurus) on the Western Ribbonsnake (Thamnophis proximus). In addition, we describe certain aspects related to the biology of each species and provide a brief description of the study site. Resumen En este documento reportamos la depredación entre dos especies simpátricas, víbor...

We document for the first time predation on a clouded anole (Norops nebulosus) by a ferruginous pygmy-owl (Glaucidium brasilianum) in a habitat on the outskirts of the city of Guadalajara, Jalisco, Mexico. Resumen Aquí documentamos por primera vez la depredación sobre la lagartija anolis del bosque neblinoso (Norops nebulosus) por un búho-pigmeo fe...

Salamanders are threatened currently by the destructive activities of humans and potentially endangered by the possibility of the invasion of their habitats by the chytrid fungus Batrachochytrium salamandrivorans. Our conclusion is that Mesoamerican salamanders should be recognized as a conservation focal group for several reasons outlined herein....

This article compiles information on different aspects of the biology of the Taylor's cantil (Agkistrodon taylori), a pit viper endemic to Mexico which can be found in the states of Hidalgo, Nuevo Leon, San Luis Potosí, Tamaulipas and Veracruz, where it inhabits thornforest and deciduous tropical forest. Specifically, this article deals with its mo...

In this note we report an incident in which two sympatric species were involved, one the great-tailed grackle as predator (Quiscalus mexicanus), and the other the neovolcanic leopard frog (Lithobates neovolcanicus) as prey. We also document some aspects of the biology of each species as components of their trophic chain. Resumen En este documento r...

During the course of an ornithological and herpetological survey in July of 2018 in the municipality of Huejutla de Reyes in the state of Hidalgo, Mexico, we observed a Trachycephalus typhonius (milky treefrog) being preyed upon by a Leptophis diplotropis (Pacific Coast parrot snake). This was an unexpected field observation, even though the distri...

Uma exsul is a micro-endemic species of the Chihuahuan desert, listed as an endangered species in NOM-059-SEMARNAT-2010. The objective was to determine the genetic population structure of U. exsul, assuming that the distribution allopatric populations constitute different lineages. Methodology: 14 field trips where carried out, collecting 24 biolog...

From 2011 to 2019, we visited 11 localities within the municipality of Huajicori in the state of Nayarit, Mexico, adjacent to natural vegetation such as low tropical deciduous forest, oak forest, oak-pine forest, and pine forest. We have found 20 amphibian and 35 reptile species, for a total of 55 species, with 30 endemic to the country. Twenty of...

The herpetofauna of Coahuila, Mexico, is comprised of 143 species, including 20 anurans, four caudates, 106 squamates, and 13 turtles. The number of species documented among the 10 physiographic regions recognized ranges from 38 in the Laguna de Mayrán to 91 in the Sierras y Llanuras Coahuilenses. The individual species occupy from one to 10 region...

During the course of a survey conducted in the municipality of Aguililla in the state of Michoacan, Mexico, we observed a Mexican leaf frog (Agalychnis dacnicolor) prey upon a tarantula (Bonnetina sp.). Predator-prey interactions between various spider and frog species have been documented many times-a phenomenon that day by day grows as more resea...

Lithobates neovolcanicus tadpoles feeding on the mesocarp of a criollo mango fruit (Mangifera indica). Artificial pond into which mango fruits fall, and provide food for Lithobates neovolcanicus tadpoles.

From 2011 to 2019, we visited 11 localities within the municipality of Huajicori in the state of Nayarit, Mexico, adjacent to natural vegetation such as low tropical deciduous forest, oak forest, oak-pine forest, and pine forest. We have found 21 amphibian and 35 reptile species, for a total 56 species, with 31 endemic to the country. Twenty-one of...

The Gulf of California islands are a priority for conservation of biodiversity in Mexico. Therefore, we need to understand the natural biodiversity and resources they support. Most of the islands are not inhabited by people; they are visited, however, by tourists, fishermen and scientists. The resulting impact on the terrestrial ecosystems has not...

Area where the predation event indicated by the star took place. The ellipse surrounds the town of Teuchitlan, Jalisco, Mexico. The double-ended arrow indicates the lake (Presa La Vega) created by a dam.

Abstract With the objective of increasing our knowledge on the herpetological composition of the municipality of Compostela, we performed surveys in different types of vegetation during the period from 2013 to 2016. This is our second survey for a particular municipality of the state. Based on the information obtained, we here report our findings o...

We conducted surveys with the purpose of expanding our knowledge of the amphibian and reptile species distributed on Volcán de Tequila. As a result of these surveys, we recorded a total of 32 species of herpetofauna, 23 of which are new records for the area. Resumen Llevamos a cabo muestreos de anfibios y reptiles con el fin de expandir el número d...

We document two new localities for Gerrhonotus liocephalusfor the state ofJalisco. These records are far from the coastline where the rest of the distribution of this species in Jalisco has been documented. Both records represent latitudinal and altitudinal distributional extensions. The first record is in the municipality of Talpa de Allende and t...

We document the first records of Gerrhonotus parvus in the state of Coahuila, México. From March 2012 to March 2017, 6 males and 2 females were found in pine forest and submontane scrubland plant communities in the Sierra de Zapalinamé Natural Protected Area, which is located in the municipalities of Saltillo and Arteaga. These records extend the k...

This document is a step forward in our knowledge of the herpetofaunal diversity of Mexico and, in particular, the state of Nayarit. The study is the based on field observations, published literature, and information from national and international preserved collections. Our survey was undertaken during 2014–2017. A total of 51 species of amphibians...

Amphibians are the most threatened vertebrate group with a third of currently known species endangered with extinction, as a result of climate change, habitat loss, disease-introduced exotic species, and pollution. Because of their vulnerability, they have often been used as environmental quality indicators, as well as laboratory models for toxicol...

During the course of field research for the “Temporal and spatial patterns of survival of the grassland specialist genus Ammodramus using radio-telemetry during the winter season in the Chihuahuan Desert of Mexico” project, conducted in the Grassland Priority Conservation Area Valle Colombia in northern Coahuila, Mexico, we recorded the predation o...

We document for the first time predation on Rhinella horribilis (cane toad / sapo gigante) by Leptodeira maculata (southern cat-eyed snake / escombrera del suroeste Mexicana) and by Caracara cheriway (northern caracara / quebranta huesos). On 1 November 2016, at 08:16 h, we observed a Leptodeira maculata consuming Rhinella horribilis without regurg...

A juvenile Bothrops asper (Terciopelo) collected in Tamaulipas, Mexico, is identified as the westernmost locality for the species range-wide. We review and map the distribution in Tamaulipas and adjacent areas of San Luis Potosí and Veracruz, Mexico, based on museum and literature records. The specimen was dissected and its stomach contained Crypto...

We document for the first time predation on Aspidoscelis communis by Conophis vittatus. The snake was observed 1 September 2016 at 12:02 h in the municipality of Cuauhtémoc, Colima, Mexico, 500 m northwest of the national airport of the city of Colima. It was active in grassland close to the airport, which still harbors patches of medium deciduous...

The herpetofauna of Nuevo León, Mexico, is comprised of 139 species, including 22 anurans, four salamanders, 106 squamates, and seven turtles. We delineate the distribution of these species among the seven physiographic regions we recognize. The number of species in these regions ranges from 20 in the Sierras Transversales to 87 in the Gran Sierra...

Twenty-four months of field sampling in a diverse and rich dry oak forest has resulted in a list of 33 species of amphibians and reptiles present in a portion of Sierra del Cuale on the Pacific Coast of Jalisco, Mexico.

Crotalus ravus exiguus y Crotalus aquilus son serpientes de cascabel de montaña endémicas del país, y se conoce muy poco sobre las actividades biológicas y la composición de sus venenos. Se evaluaron cuantitativamente las actividades de fosfolipasas A2 (PLA2) y la actividad proteolítica en caseína de los venenos totales por espectrofotometría. Adem...

The Tamaulipan rock rattlesnake (Crotalus lepidus morulus) is a montane snake that occurs in the humid pine-oak forest and the upper cloud forest of the Sierra Madre Oriental in southwestern Tamaulipas, central Nuevo Leon, and southeastern Coahuila in Mexico. Venom from this rattlesnake was fractionated by High-Performance Liquid Chromatography for...

La serpiente de la Roca de Tamaulipas (Mexico) (Crotalus lepidus morulus) es una serpiente de cascabel de montana que se encuentra en el bosque de pino-encino humedo y el bosque nuboso superior de la Sierra Madre Oriental en el suroeste de Tamaulipas, en el centro de Nuevo Leon, y el sureste de Coahuila en Mexico. El veneno de estas serpientes fue...

This is a natural history note on the texas spiny lizard. It details the act of predation on Sceloporus olivaceus by a Scolopendra heros, a species of large scolopendromorph centipede. See Comments to clarify an error within the article.

We report the first records of two species of snake in the state of Jalisco, Mexico. We recorded one specimen of Tantilla cascadae and two of Tantilla ceboruca, the former known only from its type locality. These findings extend the known geographical distribution of T. cascadae 121 km westward from Michoacán, its type locality. Also, it extends th...

We surveyed the herpetofauna at four sites affected by wildfires that occurred on different dates in the natural protected area " La Primavera, " with the purpose of identifying the differences in the community structure among the four sample sites at different stages in the recovery process. We sampled a total of 1.2 hectares per site, distributed...

Los anfibios es el grupo de vertebrados más afectado por actividades humanas, tales como la agricultura, urbanización, acuacultura, sobrepastoreo, entre otras. Por lo que han sido utilizados como indicadores de buena calidad ambiental, así como modelos de laboratorio para investigación toxicológica. Actualmente, las técnicas no letales o poco invas...

We report a female specimen of Gerrhonotus parvus that represents a new record for the municipality of Santa Catarina, Nuevo León, Mexico. This species was known previously from only three localities in the state: the municipalitiy of Galeana; the type locality, Los Rayones, where only one specimen was registered; and San Isidro Canyon in Santiago,...

The Tamaulipan rock rattlesnake (Crotalus lepidus morulus) is a small, cold-tolerant, mountain rattlesnake that occupies the Sierra Madre Oriental in southwestern Tamaulipas, central Nuevo Leon, and southeastern Coahuila in Mexico. The aim of the present study was to analyze and compare the protein profile and proteolytic activity of 16 individual...

Crotalus triseriatus, a species whose distribution is restricted to the southern mountainous areas in the state of Jalisco, was found in the protected natural area " Bosque La Primavera, " located next to the Guadalajara metropolitan area, at a lower elevation than previously reported in the literature. Resumen Crotalus triseriatus una especie cuya...

With the objective to update the amphibian and reptile species richness of the protected natural area " Estero El Salado, " surveys were conducted in different vegetation types to appraise the diversity of these sites. The biological richness represented in this natural protected area is important because the area is dedicated to protecting the man...