Influence of microhabitat use on morphology traits of three species of the Anolis sericeus complex (Squamata: Dactyloidae) in Mexico.

The relationship between microhabitat use and morphology in Anolis lizards has been well studied in the Caribbean islands. However, studies of ecomorphology are scarce for the vast majority of mainland Anolis species. Thus there is a great lack of knowledge on how microhabitat use may influence the morphology of most mainland Anolis species. In this study we evaluated the relationship between morphology and microhabitat use in three sister species of the genus Anolis (A. sericeus, A. unilobatus and A. ustus) inhabiting the mainland and examined whether sympatric coexistence with other Anolis species affects microhabitat use and morphology of Anolis sericeus. The results of this study showed that A. ustus perches on higher, thinner, and warmer branches than its sister species (A. sericeus and A. unilobatus), and that snout-vent length, arm, forearm and femur length and weight of the three species are positively correlated with perch diameter, while the number of subdigital lamellae and weight are slightly correlated with perch height. In addition, the absence of sympatric Anolis species increases the variability in perch height, weight, arm and forearm length, and hip width observed in A. sericeus. Differences in limbs length, head length, weight and number of lamellae enabled the identification of two groups of species exploiting statistically different microhabitats. The relationship between microhabitat use and morphology indicates that some morphological traits, such as locomotor structures, weight and number of subdigital lamellae of the three species are influenced by microhabitat use and that interspecific competition may reduce variability in the height of perches used.

Effects of traditional agroecosystems and grazing areas on amphibian diversity in a region of central Mexico.

Habitat loss or degradation due to land cover change is regarded as one of the main drivers of amphibian decline; therefore, it is imperative to assess the effects of land-cover change on this group of vertebrates. In this study, we analyze changes in alpha and beta diversity of amphibian communities found in five land-cover types: mountain cloud forest, tropical evergreen forest, shade coffee, milpa huasteca, and grazing areas; six samples sites were established for each land-cover type, separated at least one km away. The study was conducted in the northwest part of the state of Hidalgo, in a transition zone between the Sierra Madre Oriental and the Gulf of Mexico, which is a region rich in amphibian species. The results indicate that alpha diversity decreases with loss of canopy cover, this being high in mountain cloud forest, tropical evergreen forest, and Shade coffee, and low in milpa huasteca and grazing areas. The land-cover type with the highest species evenness was found in milpa huasteca and the lowest in. The highest beta diversity was observed among tropical evergreen forest and grazing areas. Mountain cloud forest contains both exclusive species and the highest number of species currently regarded as threatened by national and international conservation assessment systems. In order to preserve amphibian diversity in the study area it is vital to protect the last remnants of native vegetation, especially mountain cloud forest, but also including Shade coffee, since the latter habitat harbors amphibian diversity similar to that found in native forests. Finally, implementation of policies that both reduce Grazing areas and increase their productivity is also necessary, since these highly modified areas turn out to be the ones that affect amphibian diversity the most.