Daniel Cruz-Sáenz

The relative allocation of energy organisms devote to reproductive processes (aka reproductive effort) constitutes a central topic in life history theory. We document some aspects of the reproductive ecology and investment of 2 viviparous skinks of the genus Plestiodon from Mexico: an undescribed species previously assigned to P. brevirostris(Plestiodon sp., La Malinche, Tlaxcala, 2,700-3,000 m) and P. dugesii (2 populations, Mazamitla and Tapalpa, Jalisco; 2,400-2,500 m). We used relative litter mass (RLM) as a measure of reproductive effort and calculated a body condition index (BCI) as a proxy of the energy status of non-pregnant females, post-parturient females, and neonates. There were no differences in any of the reproductive characteristics between the 2 populations of P. dugesii. Both species lacked sexual size dimorphism, and female body size did not influence RLM, litter size nor litter mass. However, female BCI influenced RLM and, in P. dugesii, a larger litter size corre...

Cope's Largescale Spiny Lizards (Sceloporus utiformis) are endemic to the Pacific slope of Mexico. They are oviparous and are known to inhabit tropical and temperate forests from sea level to 1,800 m a.s.l. Here, we expand this range based on the finding, in May 2022, of two individuals of S. utiformis in the southeastern portion of the Sierra de Manantlán, at 2154 m elevation. We also provide data on morphometry and field body and microhabitat temperatures of these organisms. A previous study conducted at the same locality almost three decades ago found the species to be present at much lower elevations, so we hypothesize that this could be a case of upward range shifting due to climate change. Moreover, as few oviparous members of the genus Sceloporus occur above 2,000 m elevation, this record triggers many questions about the ecological implications of oviparity along elevation gradients.

Geographic Information Systems technology was used to analyze the distribution and species richness of the reptiles of the state of Jalisco, and its association with vegetation types, physiographic provinces, altitude, climate and herpetological provinces. Data were obtained from voucher specimens deposited in 10 national and international zoological collections, comprising 2552 catalogued specimens. We found that there are 151 species of reptiles for the state of Jalisco. The analysis demonstrated a need for stronger efforts in sampling the eastern and northern regions of the state. Resumen Utilizando los sistemas de información geográfica como herramienta se realizo el análisis de la distribución y la riqueza de las especies de reptiles para el estado de Jalisco, con relación a tipos de vegetación, provincias fisiográficas, altitud, clima y provincias herpetológicas. Este se efectuó a partir de registros obtenidos de colecciones zoológicas que tuvieran ejemplares colectados en el estado. Se obtuvo un total de 2552 registros de 10 colecciones nacionales y extrajeras. Encontramos que en Jalisco se presentan 151 especies de reptiles. El análisis dejo ver que hace falta realizar un esfuerzo importante en muestrear la región Este y Norte del estado.

Xantusia sanchezi is an endangered species that is endemic to Mexico and is known only from the states of Jalisco and Zacatecas. We studied a population from a locality known as Huaxtla, in the municipality of Zapopan in the state of Jalisco. Sampling was conducted over a period of 7 months in an area of 1.5 hectares of grassland and oak forest with boulders. Collected data included: body measurements (total length, snout-vent length, tail length, head length, head width, head height, femur length, and femoral pores), sex, weight, habitat and average temperature and humidity. Habitat characterization was made using a coverage analysis. A total of 29 individuals were captured with 7 re-captures. This work provides the first data on the biology and ecology of this species, which is known in Jalisco from only a small area under tremendous threat due to urban development.<br>Se realizó el estudio de una población de Xantusia sanchezi, una lagartija endémica de México y en peligro ...

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 the known geographical distribution of T. ceboruca 41 km eastward from its type locality and 185 km northwest from its second record in the state of Colima.

There are 14 species recognized in the North American genus Xantusia. Six of these occur in Mexico. Two species of the genus, X. bolsonae and X. sanchezi, are categorized by the Mexican government as “at risk of extinction” (SEMARNAT, 2002). Little is known about the biology, ecology, and the current status of the disjunct populations of these two species. Sanchez’s night lizard, Xantusia sanchezi, is the southernmost species and is known from southern Zacatecas and central Jalisco. This species was described by Bezy and FloresVillela (1999) from the locality of Moyahua, Zacatecas. While conducting a population ecology study of X. sanchezi, we surveyed the other herpetofauna at the sampling site. We found a total of 24 sympatric species. We categorized nine of these as possible predator species of X. sanchezi based on documented saurophagy.

of two genera: Micrurus and Micruroides (Campbell and Lamar, 2004). Micruroides is a monotypic genus that differs from the other New World coralsnakes in having a single pair of gular shields, separated prefrontal bones, a red ring that follows the pale nuchal ring, and the presence of solid maxillary teeth situated posterior to the fangs (Roze, 1974; Campbell and Lamar, 2004; Meik et al., 2007). The Sonoran Coralsnake, Micruroides euryxanthus (Kennicott, 1860), is the only species in the genus, and is distributed in Arizona and New Mexico, in the southwestern United States, southward into northwestern and western México, in the Mexican states of Chihuahua, Sonora, Sinaloa, Nayarit, and Jalisco (Roze, 1974; Campbell and Lamar, 2004; WoolrichPiña et al., 2016, Bezy et al., 2017; Cruz-Sáenz et al., 2017; Ahumada-Carrillo et al., 2018). Three subspecies are currently known on the basis of lepidosis and colour pattern (Campbell and Lamar, 2004): M. euryxanthus euryxanthus Kennicott, 186...

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 researchers are out in the field.

Herpetofaunal road mortality in the municipality of Cuauhtémoc, Colima, Mexico Roads are recurrent avenues used for the transportation of people and supplies, and vehicular traffic has been well documented as an important agent in reducing populations of amphibians and reptiles. Road mortality can contribute to local and regional declines in herpetofaunal populations, especially during peak periods when animals tend to cross roads (Lazcano et al., 2009, 2017). Coelho et al. (2012) noted road mortality as one of the principal causes of amphibian population decline worldwide. In addition to habitat fragmentation due to logging, farming, and urbanization, vehicular traffic is responsible for a high degree of vertebrate mortality. Most road-builders do not attempt to prevent or ameliorate the environmental impact of their construction, and in many cases concrete barriers between lanes prevent animals from crossing roads. Although roads should be constructed with passages that allow animals to cross these structures safely, such practices often are not considered because of their cost and the disruption it would cause to the flow of traffic. In this note, we document road mortality in amphibians and reptiles in the state of Colima. Study Methods We conducted daily surveys during two time periods: from 6 June to 11 December 2014, and from 24 April 2015 to 29 November 2016. The section of road in this study is located in the eastern part of Colima, in the municipality of Cuauhtémoc, between Cuauhtémoc and Buenavista. The section of the road we surveyed is approximately 8.5 km long. We conducted the surveys early in the morning and during the afternoon, by driving and recording the individuals found dead on the road (DOR) that had been killed by vehicular traffic. We recorded the data for every individual found, including the species identification, date, and location.

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 tropical forest. The snake measured 480 mm snout–vent length and 220 mm tail length, a total length of 700 mm.

As part of an investigation into the ecology and biology of Xantusia sanchezi, excreta were collected with the aim of studying the diet of the species. Samples were analyzed by identifying the structures useful for taxonomic determinations. We identified remains from four orders of insects. Within two of the orders we could identify the family and within one family we were able to distinguish six species. Resumen Como parte de una investigación sobre la ecología y biología de Xantusia sanchezi se realizó la colecta de excretas de estas lagartijas con la intención de conocer sobre los elementos que constituyen la dieta de esta especie. Se analizaron las muestras realizando la identificación de las estructuras para conocer a cual grupo de organismos pertenecen. Logrando identificar a cuatro ordenes, dos familias y seis especies de insectos.

There are 14 species recognized in the North American genus Xantusia. Six of these occur in Mexico. Two species of the genus, X. bolsonae and X. sanchezi, are categorized by the Mexican government as " at risk of extinction " (SEMARNAT, 2002). Little is known about the biology, ecology, and the current status of the disjunct populations of these two species. Sanchez's night lizard, Xantusia sanchezi, is the southernmost species and is known from southern Zacatecas and central Jalisco. This species was described by Bezy and Flores-Villela (1999) from the locality of Moyahua, Zacatecas. While conducting a population ecology study of X. sanchezi, we surveyed the other herpetofauna at the sampling site. We found a total of 24 sympatric species. We categorized nine of these as possible predator species of X. sanchezi based on documented saurophagy.

We collected a pregnant female mountain skink (Plestiodon callicephalus) and the eggs from two nests of this species from the vicinity of Huaxtla, Zapopan, Jalisco. The female was kept in captivity until oviposition. All eggs were kept until hatching. We report on behavior we observed that we characterize as parental care. We provide information on clutch size, egg size and hatchling size in this species. Resumen Fue colectada una hembra y dos nidos de Plestiodoncallicephalus en la localidad de Huaxtla, Zapopan, Jalisco. Estas fueron mantenidas en cautiverio hasta que se llevo a cabo la puesta del nido y posteriormente la eclosión de las crías. Se observaron algunas conductas de cuidado parental y fueron caracterizados los huevos y el tamaño de las crías. Con este trabajo pretendemos aportar información sobre la caracterización de los tamaños de los huevos y crías de esta especie.

Intensive sampling was conducted to study the herpetofauna of the oak forest in the locality of Huaxtla, Zapopan, Jalisco, Mexico; the search was done in feasible habitats such as under rocks, in crevices, trees, leaf litter. Sampling was conducted in an area of 1.8 ha, during the period from July to December of 2010. We registered 30 Plestiodon callicephalus, of which 23 were adults, five were juveniles and two were neonates. Of these, two females with their eggs were observed conducting parental care. This is the first report of parental care for the species in Mexico. Resumen Para este estudio se realizaron muestreos intensivos de herpetofauna en un bosque de encino localizado en Huaxtla, Zapopan, Jalisco, México. La búsqueda se llevó a cabo entre los microhábitats viables como son: bajo rocas, en las grietas, árboles, hojarasca, etc. El muestreo se realizó en un área de 1,8 ha, durante el período comprendido entre julio y diciembre de 2010. Registramos 30 individuos de Plestiodon callicephalus, de los cuales 23 eran adultos, cinco eran juveniles y dos fueron recién eclosionados. De éstas, dos hembras con sus huevos fueron observados realizando cuidado parental. Este es el primer reporte de cuidado parental en una especie de escíncido para México.

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 in 6 band transects and compared the richness, abundance and diversity. The sample sites affected by wildfires have high diversity, richness and evenness values. The sample sites with greater recovery time after the wildfire have the lowest values. This project is very important because the high number of wildfires in the natural protected area each year and the meager information about the effects of fire on the fauna. Resumen Se realizó el muestreo de reptiles en 4 sitios afectados por los incendios forestales ocurridos en diferentes fechas dentro del área de protección de flora y fauna bosque La Primavera, con la finalidad de conocer las diferencias en la estructura de la comunidad de reptiles en cada uno de los sitios en recuperación a través de un gradiente de perturbación. Se muestrearon 1.2 hectáreas por sitio mediante 6 transectos en banda y posteriormente se realizó el análisis de riqueza, abundancia y diversidad. El sitio recientemente afectado resultó con el valor de diversidad más alto, la mayor riqueza y la mayor equidad, mientras los dos sitios con un mayor tiempo de recuperación obtuvieron los valores más bajos. Este estudio resulta relevante debido a la gran cantidad de incendios que se presentan es está área natural protegida y a la poca información respecto al efecto que estos tienen sobre la fauna.

From June 2012 to December 2014, we conducted several surveys at a locality known as Barranca El Tecolote, in the municipality of Mazamitla, Jalisco, Mexico. Working on a date list of the herpetofauna of the area, a total of five species of amphibians and 14 reptile species have been found. Nine of these species are protected by the Mexican environmental law NOM-ECOL-059, and several more fall into a high category of vulnerability. Moreover, two snake records (Geophis petersii and Crotalus pusillus) represent local range extensions. Notwithstanding the relatively small area sampled, the species richness and endemism is considerable. The increase in local human activities, such as land conversion and illegal logging and hunting, constitute the nearest menace to the biodiversity of the area. Likewise, we noticed a widespread aversion by the residents to many of the native amphibians and reptiles due to baseless beliefs, often resulting in the sacrifice of harmless species.

To determine the current status of the populations of green iguana (Iguana iguana) and western spiny-tailed iguana (Ctenosaura pectinata) we conducted surveys each month for a year at three locations in the " Estero El Salado. " Our objectives included identifying the causes for the decrease in iguana populations and determining abundance for adults, males, females and hatchlings.

To update the estimate of species richness of amphibians and reptiles in the biotic community known as Huaxtla, in the municipality of Zapopan, Jalisco, we reviewed existing literature concerning species previously registered on the site and conducted monthly sampling over a period of 19 months. Here we report a list of 36 species of amphibians and reptiles. We emphasize the importance of this site due to its location in a transition zone from tropical deciduous forest to evergreen oak forest, enhancing its species diversity. Resumen Con la intención de actualizar y dar a conocer la riqueza de especies de anfibios y reptiles en la comunidad conocida como Huaxtla, en el municipio de Zapopan Jalisco se revisó literatura sobre las especies previamente registradas en el sitio y se realizaron muestreos mensuales en por un periodo de 19 meses teniendo finalmente un listado de 36 especies de anfibios y reptiles. Además queremos enfatizar su importancia como un sitio altamente rico y diverso por su transición del bosque tropical caducifolio a encinar, aumentado su diversidad especifica.

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 mangroves and other vegetation that has high species richness.

Sampling of amphibians and reptiles was conducted in the municipality of Hostotipaquillo in the northern part of the state of Jalisco. After six months of fieldwork 60 species were registered. This field work was conducted to determine the previously undocumented species richness of the municipality.

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 distribución se restringe a las zonas serranas del sur del estado de Jalisco, fue encontrada en el área natural protegida " Bosque La Primavera " que se encuentra próximo a la zona metropolitana de Guadalajara a una elevación menor a la reportada en la literatura.

The herpetofauna of Jalisco, Mexico, is comprised of 223 species, including 47 anurans, four
salamanders, one caecilian, one crocodylian, 158 squamates, and 12 turtles. We document the distribution
of these species among the seven physiographic regions we recognize. The number of species in
these regions ranges from 38 in the Sierra de Coalcomán and the Tepalcatepec Depression to 116 in the
Trans-Mexican Volcanic Belt. The species occupy from one to seven regions (x– = 2.6). The number of
species shared between physiographic regions ranges from 19 between the Pacific Coastal Plain and the
Tepalcatepec Depression to 69 between the Trans-Mexican Volcanic Belt and the Central Plateau, with the
Coefficient of Biogeographic Resemblance (CBR) values ranging from 0.21 to 0.68. The greatest number
of single-region species (33) is restricted to the Pacific Coastal Plain. About 61% of the species in Jalisco
are confined to one or two physiographic regions, which is of great conservation significance. We developed
a CBR matrix in which the number of shared species ranges from 19 to 69. We utilized these data
to build a UPGMA dendrogram, which indicates that two distinct clusters of multiple pairwise groupings
united at a CBR level of 0.41 are present, as well as an outlier consisting of the Pacific Coastal Plain region
(PC) joined to the other six regions at a CBR level of 0.35. None of the seven regions illustrate high
resemblance patterns; the highest CBR value (0.68) is that between the Tepalcatepec Depression (TD)
and Sierra de Coalcomán (SC) regions, which lie adjacent to one another in the southeastern sector of the
state. The next highest resemblance (0.66) is that between the Trans-Mexican Volcanic Belt (TV) and the
Central Plateau (CP) regions, which share a lengthy border in the central portion of the state. This pair of
regions is next most closely related to the Sierra Madre Occidental (SO) region, with a value of 0.60; both
TV and CP lie adjacent to the Sierra Madre Occidental in north-central Jalisco. The last region, the Sierras
Jaliscienses (SJ), joins the SO-TV-CP group at a level of 0.54. Against expectations, the TD region shares
little resemblance (0.28) to the PC region, even though these two regions share a connection through the
Río Balsas Basin in southern Michoacán. The most distinctive herpetofaunal assemblage is located within
the Pacific Coastal Plain, which contains the most single-region species (33) and the highest number of country endemics (15). We allocated the members of the herpetofauna to four distributional categories,
of which the largest number is comprised of the country endemic species (142), followed by the non-endemics
(75), the non-natives (4), and the state endemics (2). We identified the principal environmental
threats as climate change, population growth, habitat fragmentation due to excessive urban development,
agricultural expansion, logging, soil erosion, soil compaction, desertification, air and water pollution,
unregulated dumping of waste, open pit mining, illegal hunting, and commercial trade. We evaluated the
conservation status of the native species by using the SEMARNAT, IUCN, and EVS systems, of which
the EVS proved to be the most helpful. The number of species in the three EVS categories increased from
low (51) through medium (74), to high (88). In addition, we utilized the EVS rankings to evaluate how the
species in the IUCN categories of NE and LC might be assessed more accurately. We also utilized a means
for determining Relative Herpetofaunal Priority (RHP), a simple scheme for ascertaining the rank order
of a physiographic regional herpetofauna dependent on the number of state and national endemic species,
in addition to the number of high vulnerability EVS species. By employing these two measures, we determined
the Trans-Mexican Volcanic Belt to occupy rank number one in both cases. We discuss the impact
of global environmental issues on Jalisco, as well as the ability of the state’s 20 protected areas to provide
sanctuary for the members of the herpetofauna. Based on our analysis, we developed a set of conclusions
and recommendations for the perpetual protection of the herpetofauna of Jalisco.