Diet of two populations of Sceloporus grammicus was determined from Tilcuautla and La Estanzuela, Hidalgo, Mexico. Diet of S. grammicus is primarily Araneae, Insecta (Coleoptera, Dermaptera, Diptera, Hemiptera, Homoptera, Hymenoptera Lepidoptera, and Orthoptera), Mollusca (gastropods), and Reptilia (Sauria). Hymenoptera and Coleoptera were most frequent in the diet of both populations. These groups were more abundant and more diverse in diet of lizards from Tilcuautla than in those from La Estanzuela. Breadth of diet for males from Tilcuautla was B = 0.108 and for females was B = 0.101, and in La Estanzuela was B = 0.183 and B = 0.095 for males and females, respectively. Overlap between males and females from Tilcuautla was O_jk = 1.000, with percentage overlap of 97.0–100%, and for La Estanzuela overlap was O_jk = 0.938, with percentage overlap of 76.3–100%. Based on the feeding-importance value (ViI), coleopterans and hymenopterans were the most important orders in the diet of S. grammicus for both populations and sexes. Diet of S. grammicus is mainly insectivorous with a tendency to specialization on coleopterans and hymenopterans, but this species could be a generalist at some time during the year as indicated by this study. Se determinó la dieta de dos poblaciones de la lagartija Sceloporus grammicus de las localidades de Tilcuautla y La Estanzuela, Hidalgo, México. La dieta de S. grammicus es principalmente Araneae, Insecta (Coleoptera, Dermaptera, Diptera, Hemiptera, Homoptera, Hymenoptera, Lepidoptera y Orthoptera), Mollusca (Gastrópoda) y Reptilia (Sauria). Las presas más frecuentes en las dietas fueron los himenópteros y los coleópteros. Estos grupos fueron más abundantes y diversos en la dieta de las lagartijas de Tilcuautla que en La Estanzuela. En Tilcuautla, la amplitud de nicho alimentario para los machos fue de B = 0.108 y para las hembras de B = 0.101, mientras que en La Estanzuela fue de B = 0.183 y B = 0.095, respectivamente. El solapamiento alimentario entre machos y hembras de Tilcuautla fue de Ojk = 1.000, con un porcentaje de solapamiento de 97.0–100% y para La Estanzuela de Ojk = 0.938, con un porcentaje de solapamiento de 76.3–100%. Mediante el valor de importancia alimentario (ViI), se determinó que los coleópteros e himenópteros fueron los órdenes de presas más importantes en la dieta de S. grammicus, tanto entre poblaciones como entre sexos. La dieta de S. grammicus es principalmente insectívora con tendencia a la especialización en presas como coleópteros e himenópteros. Pero también se puede considerar como una especie generalista en algunas partes del año como lo observado en este estudio.

The spiny lizard Sceloporus grammicus (Squamata: Phrynosomatidae) is a small reptile from central México and the southern United States, occurring in a wide geographic area characterized by extensive variation in topographic and climatic regimes. Genetic variation among lineages from central México is substantial, though the extent to which this variation corresponds with life‐history traits remains obscure. To address part of this puzzle, we studied a population of S. grammicus from Tepeapulco, Hidalgo, México. Male‐biased sexual dimorphism was extensive in this population; males were larger than females overall, and expressed proportionately larger heads and longer limbs. Minimum size at sexual maturity was similar in the sexes (males: 43 mm; females: 42 mm). In contrast to other populations from the Central Plateau, reproductive activity of males and females was synchronous. Testicular recrudescence of adult males was initiated in October–November, and maximum testis size maintained from December to July. Female reproductive activity showed no clear seasonal pattern: females had vitellogenic follicles from October to July, and pregnant females were found throughout the year. Female body size was not related to litter size. Neither male nor female gonadal mass was correlated with any abiotic environmental variable examined. Differences in reproductive characteristics among populations of S. grammicus might be indicative of plasticity in response to local environmental conditions, local adaptation, or complex gene × environment interactions. We consider these results in the context of previously studied populations of S. grammicus from the Central Plateau and elsewhere, and propose directions for future research.

Amphibians and reptiles are two groups of vertebrates that are sensitive to changes in their environment. These changes are mostly caused by human activities, which affect the abundance, composition, and distribution of these vertebrates. In this study, we compare the richness and taxonomic diversity of herpetofauna between undisturbed environments (tropical deciduous forest = TDF) and disturbed environments (corn fields = CF) near the towns of Urireo (URI) and San Nicolas de los Agustinos (SNA) in Salvatierra, Guanajuato. We recorded a total of 19 species in the two locations (4 amphibian and 15 reptile species). At the URI locality, 12 species were recorded in CF and 10 in TDF. At the SNA locality, eight species were recorded in CF and seven species in TDF. In addition, we found that overall taxonomic distinctness was greater at URI than SNA across both types of vegetation, with the highest diversity found in TDF of URI. Seven of the 19 species recorded are current allocated to some protection category of NOM-059-SEMARNAT-2010: Lithobates neovolcanicus, Kinosternon integrum, Sceloporus grammicus, Lampropeltis polyzona, Masticophis mentovarius, Salvadora bairdi, and Thamnophis melanogaster differing from other mechanisms such as the International Union for Conservation of Nature and Environmental Vulnerability Score. Our results suggest that carrying out long-term studies that include diversity and taxonomic distinctness in environments with different levels of disturbance, in addition to including characteristics of natural history, might enhance the development of more efficient conservation strategies for these vertebrates.