Modelling the effects of climate and land-cover changes on the potential distribution and landscape connectivity of three earth snakes (Genus Conopsis, Günther 1858) in central Mexico.

Anthropogenic land use and climate change are the greatest threats to biodiversity, especially for many globally endangered reptile species. Earth snakes (Conopsis spp.) are a poorly studied group endemic to Mexico. They have limited dispersal abilities and specialized niches, making them particularly vulnerable to anthropogenic threats. Species distribution models (SDMs) were used to assess how future climate and land-cover change scenarios might influence the distribution and habitat connectivity of three earth snakes: Conopsis biserialis (Taylor and Smith), C. lineata (Kennicott), and C. nasus (Günther). Two climate models, CNRM-CM5 (CN) and MPI-ESM-LR (MP) (Representative Concentration Pathway 85), were explored with ENMeval Maxent modelling. Important SDM environmental variables and environmental niche overlap between species were also examined. We found that C. biserialis and C. lineata were restricted by maximum temperatures whereas C. nasus was restricted by minimum ones and was more tolerant to arid vegetation. C. biserialis and C. lineata were primarily distributed in the valleys and mountains of the highlands of the TMBV, while C. nasus was mainly distributed in the Altiplano Sur (Zacatecano-Potosino). C. lineata had the smallest potential distribution and suffered the greatest contraction in the future whereas C. nasus was the least affected species in future scenarios. The Sierra de las Cruces and the Sierra Chichinautzin were identified as very important areas for connectivity. Our results suggest that C. lineata may be the most vulnerable of the three species to anthropogenic and climate changes whereas C. nasus seems to be less affected by global warming than the other species.

Hypoxia by Altitude and Welfare of Captive Beaded Lizards (Heloderma Horridum) in Mexico: Hematological Approaches.

Heloderma horridum is one of the few known venomous lizards in the world. Their populations are in decline due to habitat destruction and capture for the pet trade. In México, many zoos have decided to take care of this species, most of them at altitudes greater than the natural altitudinal distribution. However, we know little about the capacity of the reptiles to face high-altitude environments. The objective of this study was to compare hematological traits of H. horridum in captivity in high and low altitude environments. Our findings show that H. horridum does not respond to hypoxic environments, at least in blood traits, and that the organisms appear to be in homeostasis. Although we cannot know if individual H. horridum housed in high-altitude environments are completely comfortable, it appears hypoxia can be avoid without modifications of blood parameters. We suggest that future work should address changes in metabolic rates and in behavioral aspects to understand how to maintain the health and comfort of the reptiles native to low altitude when they are housed in high-altitude environments.

[Seasonal changes in the dorsal coloration in the lizard Aspidoscelis costata costata (Squamata: Teiidae)]. / Cambio estacional en la coloración dorsal de la lagartija Aspidoscelis costata costata (Squamata: Teiidae).

Color and color patterns in animals are important characteristics that bring protection, by dampening the ability of predators that depend on their sight to detect their preys. In lizards, the dorsal coloration plays a key role in communication of intraspecific signals such as social cues. In this study, we evaluated the seasonal changes in the dorsal coloration of the wide foraging lizard A. costata costata, in Tonatico, State of Mexico, Mexico. The seasonal evaluation included: the rainy season from mid June to mid September (can also include the end of May to early October); and the dry season for the rest of the year. The dorsal coloration of A. costata costata and their microhabitats were evaluated by contrasting the color pattern with an identification guide and the control colors of Pantone, during 11 samplings carried out from February-October 2007. Individual lizard analysis recorded snout-vent length, sex and stage (juveniles and adults). Besides, all animals were marked by toe-clipping, allowing to distinguish dorsal coloration between seasons, sex and stage. A total of 95 lizards were analyzed (53 and 42 for the dry and rainy seasons respectively). We found that the dorsal coloration in A. costata costata varies seasonally and with microhabitats: during the dry season individuals show a brown coloration whereas during the rainy season becomes greener, as the background dominant vegetation color. The results of the present study suggest that: 1) the variation in dorsal coloration in A. costata costata plays an important role in the survival (by cryptic camouflage) of this widely foraging species; 2) the changes in the dorsal coloration of A. costata costata are individually expressed traits, since the coloration of the same lizard is either brown or green depending on the season; and 3) the cryptic functions of the dorsal coloration in widely foraging species have been largely underestimated. We discuss the possible influence of the changes in coloration in an habitat that changes drastically between both dry and rainy seasons.

Cambio estacional en la coloración dorsal de la lagartija Aspidoscelis costata costata (Squamata: Teiidae) / Seasonal changes in the dorsal coloration in the lizard Aspidoscelis costata costata (Squamata: Teiidae)

Seasonal changes in the dorsal coloration in the lizard Aspidoscelis costata costata (Squamata: Teiidae). Color and color patterns in animals are important characteristics that bring protection, by dampening the ability of predators that depend on their sight to detect their preys. In lizards, the dorsal coloration plays a key role in communication of intraspecific signals such as social cues. In this study, we evaluated the seasonal changes in the dorsal coloration of the wide foraging lizard A. costata costata, in Tonatico, State of Mexico, Mexico. The seasonal evaluation included: the rainy season from mid June to mid September (can also include the end of May to early October); and the dry season for the rest of the year. The dorsal coloration of A. costata costata and their microhabitats were evaluated by contrasting the color pattern with an identification guide and the control colors of Pantone®, during 11 samplings carried out from February-October 2007. Individual lizard analysis recorded snout-vent length, sex and stage (juveniles and adults). Besides, all animals were marked by toe-clipping, allowing to distinguish dorsal coloration between seasons, sex and stage. A total of 95 lizards were analyzed (53 and 42 for the dry and rainy seasons respectively). We found that the dorsal coloration in A. costata costata varies seasonally and with microhabitats: during the dry season individuals show a brown coloration whereas during the rainy season becomes greener, as the background dominant vegetation color. The results of the present study suggest that: 1) the variation in dorsal coloration in A. costata costata plays an important role in the survival (by cryptic camouflage) of this widely foraging species; 2) the changes in the dorsal coloration of A. costata costata are individually expressed traits, since the coloration of the same lizard is either brown or green depending on the season; and 3) the cryptic functions of the dorsal coloration in widely foraging species have been largely underestimated. We discuss the possible influence of the changes in coloration in an habitat that changes drastically between both dry and rainy seasons.

En lagartijas la coloración corporal es importanteen la comunicación así como en la protección contra los depredadores. Con el uso de una guía Pantone®, se analizó el cambio estacional en la coloración dorsal y los microhábitats de Aspidoscelis costata costata, una lagartija de amplio forrajeo que habita un ambiente (en el Estado de México, México) que cambia drásticamente de apariencia entre sequía y lluvias. Se analizó la dependencia de la coloración dorsal de acuerdo a la estación, sexo y estadio de desarrollo. Los resultados indican que la lagartija A. costata costata presenta una coloración dorsal similar al sustrato en cada estación: parda en sequía y principalmente verde en lluvias. Este estudio sugiere: 1) Que la variación en coloración dorsal con funciones crípticas, como la registrada en A. costata costata, puede resultar importante en la supervivencia de especies de amplio forrajeo; 2) Que el cambio en la coloración dorsal en A. costata costata es a nivel individual, ya que un individuo presente en ambas estaciones manifiesta una coloración dorsal parda en la estación de sequía y una coloración dorsal verde en la estación de lluvias y 3) Que la coloración dorsal, con funciones crípticas, está subestimada en especies de amplio forrajeo.