To be small and dark is advantageous for gaining heat in mezquite lizards, Sceloporus grammicus (Squamata: Phrynosomatidae)

Body temperature is important in determining individual performance in ectotherms such as lizards. Environmental temperature decreases with increasing altitude, but nevertheless many lizards inhabit high-altitude environments. The ‘thermal melanism hypothesis’ proposes that a dark dorsal coloration enables darker individuals to heat up faster because they absorb more solar radiation and thus being darker may be advantageous in cold habitats. The aim of the present study is to evaluate how heating rate, cooling rate and net heat gain vary with body size and dorsal skin coloration in Sceloporus grammicus lizards along an altitudinal gradient. We measured these traits multiple times in the same individuals with a radiation heat source and spectrophotometry under laboratory conditions. Our results showed that S. grammicus lizards are smaller and darker at high elevations than at low elevations. In addition, the smallest and darkest lizards showed the greatest heating rate and net heat gain. Therefore, in S. grammicus, we suggest that small body size and dark dorsal coloration provide thermoregulatory benefits in high-altitude environments. Hence, this study supports the thermal melanism hypothesis in a lizard species under varied thermal environments.

Intraspecific variation in a lizard from the Central Mexican Plateau: intersexual differences in size and shape explored

Morphological adaptations of individuals are directly (or indirectly) determined by the environment. Depending on sex, these adaptations may vary in different ways, given that different selective forces may be operating on organisms. Here, we evaluate intraspecific morphological variation (size and shape) in two populations of Sceloporus grammicus that occur in different structural habitats (trees and rocks). No difference in overall body size was found between the two populations. However, strong differences were found in body shape; the tree population was characterized by having shorter hindlimb proportions than the rock population, which agrees with the theory of biomechanical models. Furthermore, our results show that this species is dimorphic in size and shape, both in sex and population effects. A review of the literature suggests that the large overall body size and relatively longer distal segments of males could be an advantage for defending their territory, and the observation that females had relatively longer head length may be related to trophic niche divergence; however, this remains to be tested. Detailed quantification of behaviour, performance and reproductive characteristics must be performed to shed light on the evolution of sexual dimorphism in this widely distributed species in Mexico.

FIRST RECORD AND DIET OF THE TEXAS PATH-NOSED SNAKE (Salvadora grahamiae lineata) IN PUEBLA, MEXICO

We report the first record of Salvadora grahamiae lineata in Northern Puebla State, Mexico, and we examined the stomach contents founded two partially digested Sceloporus grammicus (graphic spiny lizard). This report increased to four species of path-nosed snakes, genus Salvadora, in Puebla State, and extending the known distribution of S. grahamiae lineata southern of San Miguel Regla, Hidalgo, into the Puebla state. This is de first record of Sceloporus grammicus in the diet of S. grahamiae lineata and the third record of the genus Sceloporus as diet of the Salvadora snakes.

Cuicatec ethnozoology: traditional knowledge, use, and management of fauna by people of San Lorenzo Pápalo, Oaxaca, Mexico

Background The Tehuacán-Cuicatlán Valley is a region of outstanding biocultural diversity, harboring eight indigenous ethnic groups and a remarkable biodiversity in a territory 10,000 km2 extent. Ethnobotanical studies of the region are among the most complete in Mexico; contrarily, ethnozoological studies are still limited. But information on both flora and fauna use and management is relevant for understanding local cultural and ecological issues, and for planning integral strategies of biodiversity conservation. Our study focused on analyzing knowledge and use of animals and their relationship with faunistic management by the Cuicatec, an ancient human culture whose distribution is restricted to the region. We hypothesized that wild animals still have significant contributions to diet, medicine, and spiritual life of the Cuicatec people. In addition, we expected to find a gradient of interactions, from simple gathering and hunting to communitarian regulations of use, specialized management techniques and care, nurturing, and domestication of animals. Such gradient of management interactions would be influenced proportionally with cultural and economic values, viability maintenance, and scarcity of animals. Methods Our study was carried out in San Lorenzo Pápalo, Oaxaca. We conducted surveys and semi-structured and open interviews to people to document the Cuicatec nomenclature, classification, use, and management of fauna, as well as their perceptions about abundance, risks of disappearance, and availability of wild animals. We used images of animal species reported for the area as communication stimuli for confirming their local presence. Also, we recorded skins and skulls used as trophies and ornamental objects, pawprints, and excretes. Through free listing, we identified the most meaningful species of different animal groups. Whenever possible, we evaluated amounts of animals obtained from the wild, and for some species, we compared this information with data on their distribution and abundance evaluated through ecological sampling, to explore indicators on their sustainable use. Results The Cuicatec name all animals through the term i-ti and classify them in several groups of vertebrates, arthropods, and mollusks, some of them coinciding with the formal taxonomy and some others based on their social-cultural role. The most meaningful animals are 23 species of edible organisms, outstandingly the chicatana ants (Atta mexicana) and the cuetla Lepidoptera larvae (Arsenura armida), the lizard Sceloporus grammicus, and among the mammals some squirrels (Sciurus spp.), badgers (Nasua narica), and deer (Odocoileus virginianus). Some species were reported to be used for medicinal purposes, among them opossum (Didelphis spp.) and macaws (Ara militaris), used to ease childbirths, but this use almost disappeared. Local perception of availability of animal resources is associated to forest conservation. Regulations for protecting forests and the most used animal species were recorded; the rules are mainly associated to hunting and gathering seasons, respecting females of vertebrate species, and permits for gathering and hunting given by local authorities. Nurturing of animals was recorded in bird and mammal species, but in no case, their breeding was achieved. Conclusions Animals are important elements of the Cuicatec culture and subsistence, complementing their diet based on agricultural products. Animals used as medicine were still reported but substituted by modern medicine. There is a consensus about the need to conserve forests to ensure the maintenance of animals, which are valued as part of nature, the beauty of their territory, and culture. Communitarian regulations are the main ways for conserving fauna, but local techniques of animal management may help in designing conservation strategies.

Herpetofauna de la Estación Forestal Experimental Zoquiapan (EFEZ), México: Análisis de su diversidad en tres hábitats distintos

Se analizaron los patrones de diversidad de anfibios y reptiles en tres hábitats distintos de un ambiente templado: Pino, Pino-Aile y Pino-Oyamel de la Estación Forestal Experimental Zoquiapan (EFEZ), en el área natural protegida Parque Nacional Iztaccíhuatl-Popocatépetl-Zoquiapan. Se realizaron muestreos sistemáticos de la herpetofauna en transectos en banda de 1,000 m de largo por 10 m de ancho, de 2015 (mayo-julio y septiembre-noviembre) a 2016 (enero-marzo). Se registró un total de 4,762 individuos correspondientes a siete familias, diez géneros y 15 especies (cinco anfibios y diez reptiles). Las familias con más especies y abundancia fueron Phrynosomatidae y Pletodontidae. La riqueza de especies fue mayor (15 especies) en el hábitat Pino-Aile, mientras que la abundancia fue significativamente más alta ( = 70.18 ind./ha) en el hábitat Pino. El hábitat Pino-Oyamel presentó la menor riqueza (13 especies) y abundancia ( = 36.66 ind./ha). La mayor diversidad (1D = 5.16) se registró en Pino-Aile, seguido por Pino-Oyamel (1D = 4.01) y Pino (1D = 3.84). La distribución de abundancias de las especies se ajustó a la serie logarítmica de Fisher. Las especies más comunes en los tres hábitats fueron Sceloporus grammicus y Pseudoeurycea leprosa, mientras que todas las serpientes se consideraron especies raras. El 86.7% de las especies son endémicas a México, de las cuales 69.2% son endémicas a la Faja Volcánica Transmexicana. El 33.3% de las especies están amenazadas y el 26.7% sujetas a protección especial en la NOM-059-2010. Cuatro de ellas están categorizadas por la IUCN, de las cuales 6.7% está en peligro, 13.3% es vulnerable y 6.7% está casi amenazada. En términos de la relación especies-área, la riqueza de especies de anfibios y reptiles, y la presencia de endemismos en la EFEZ son altas. Este estudio contribuye a un conocimiento sobre la riqueza, abundancia, distribución y diversidad de anfibios y reptiles de los hábitats templados de la estación, que sentará precedentes para el desarrollo de estrategias futuras de conservación de la biodiversidad y en particular de la herpetofauna.

High-mountain altitudinal gradient influences thermal ecology of the Mesquite Lizard (Sceloporus grammicus)

The thermal requirements of ectotherms may vary among species due to adaptation to different thermal environments. Nevertheless, some of these requirements are evolutionarily conserved, leading organisms to compensate behaviorally for harsh environmental conditions. High-mountain systems provide temperature gradients that allow for studies of evolutionary and plastic variation in thermal ecology under natural conditions. We evaluated the thermoregulation strategies of Sceloporus grammicus Wiegmann, 1828 at three points (2600, 3100, and 4150 m above sea level) along an altitudinal gradient. We found that the thermal quality of the site and the body temperatures of lizards are influenced by altitude and decrease with increasing elevation. However, lizards from the three different elevations have similar thermal requirements. High-altitude lizards have lower thermal accuracy and efficiency indices compared with those from the lower sites, owing to the low thermal quality of their environment. Nevertheless, they are efficient in thermoregulation, increasing their body temperature above the ambient temperature. We found that pregnant females from all three elevations had similar preferred body temperatures. Compared with nonpregnant females and males, they exhibited lower preferred temperatures and more accurate thermoregulation. The wide altitudinal distribution of S. grammicus is thus not caused by variable thermal requirements. Instead, the wide repertoire of physiological and behavioral strategies of these lizards allows this species to successfully inhabit contrasting environments.