No abstract

One of the most important concepts in Panbiogeography is the generalized track, which represents an ancestral biota fragmented by geological events that can be recovered through several methods, including Parsimony analysis of endemicity (PAE) and endemicity analysis (EA). PAE has been frequently used to identify generalized tracks, while EA is primarily designed to find areas of endemicity, but has been recently proposed for identifying generalized tracks as well. In this study we evaluated these methods to find generalized tracks using the distribution of the 84 snake species of Hidalgo. PAE found one generalized track from three individual tracks (Agkistrodon taylori, Crotalus totonacus and Pliocercus elapoides), supported by 89 % of Bootstrap, and EA identified two generalized tracks, with endemicity index values of 2.71-2.96 and 2.84-3.09, respectively. Those areas were transformed to generalized tracks. The first generalized track was retrieved from three individual tracks (Micrurus bernadi, Rhadinaea marcellae and R. quinquelineata), and the second was recovered from two individual tracks (Geophis mutitorques and Thamnophis sumichrasti). These generalized tracks can be considered a unique distribution pattern, because they resembled each other and agreed in shape. When comparing both methods, we noted that both are useful for identifying generalized tracks, and although they can be used independently, we suggest their complementary use. Nevertheless, to obtain accurate results, it is useful to consider theoretical bases of both methods, along with an appropriate choice of the size of the area. Results using small-grid size in EA are ideal for searching biogeographical patterns within geopolitical limits. Furthermore, they can be used for conservation proposals at state level where endemic species become irreplaceable, and where losing them would imply the extinction of unique lineages.

Hasta la fecha se habían registrado únicamente tres especies del género Thamnophis en la Reserva de la Biosfera Barranca de Metztitlán, Hidalgo, pero gracias al trabajo de monitoreo que realiza la Brigada Comunitaria de Rescate y Conservación de las Serpientes de esta área natural protegida, fue posible registrar por primera vez la presencia de T. eques.

Los estudios recientes acerca de la herpetofauna de Hidalgo únicamente consideran a una especie del género Pituophis presente en la entidad (P. deppei). Sin embargo, existen registros previos de P. catenifer que no han sido tomados en cuenta. Por otro lado, a partir del trabajo de campo realizado al norte del estado, se registraron otros cuatro ejemplares P. catenifer en los municipios de San Felipe Orizatlán y Huejutla de Reyes, lo que corrobora la presencia de esta especie en Hidalgo.