1. Centro de Estudios en Zoología, CUCBA, Universidad de Guadalajara, Apartado. Postal. 1-1919, Guadalajara, Jalisco, 44101, México. 2. Universidad Autónoma de Nuevo León, Facultad de Ciencias Biológicas, Laboratorio de Herpetología, Apartado Postal - 513, San Nicolás de los Garza, C.P. 66450 Nuevo León, México. 3. Centro Universitario de la Costa, Universidad de Guadalajara. Bull. Chicago Herp. Soc. 44(10):1-, 2009 Notes on the Herpetofauna of Western Mexico 2: Distribution Patterns of Reptiles in the Mexican State of Jalisco Daniel Cruz-Sáenz , David Lazcano , Sergio Guerrero and Jorge Téllez-López 1 2 1 3 Abstract Geographic Information Systems technology was used to analyze the distribution and species richness of the reptiles of the state of Jalisco, and its association with vegetation types, physiographic provinces, altitude, climate and herpetological provinces. Data were obtained from voucher specimens deposited in 10 national and international zoological collections, comprising 2552 catalogued specimens. We found that there are 151 species of reptiles for the state of Jalisco. The analysis demonstrated a need for stronger efforts in sampling the eastern and northern regions of the state. Resumen Utilizando los sistemas de información geográfica como herramienta se realizo el análisis de la distribución y la riqueza de las especies de reptiles para el estado de Jalisco, con relación a tipos de vegetación, provincias fisiográficas, altitud, clima y provincias herpetológicas. Este se efectuó a partir de registros obtenidos de colecciones zoológicas que tuvieran ejemplares colectados en el estado. Se obtuvo un total de 2552 registros de 10 colecciones nacionales y extrajeras. Encontramos que en Jalisco se presentan 151 especies de reptiles. El análisis dejo ver que hace falta realizar un esfuerzo importante en muestrear la región Este y Norte del estado. Introduction The distribution of living organisms have been studied for some years using the Geographic Information Systems (GIS) tool and in particular some GAP (Geographic Approach to Protection of Biological Diversity) models. These provide a fast glance at the distribution and conservation status of various components or indicators of biodiversity. This analysis orga- nizes the existing information to identify or detect areas of high biodiversity that need to be put aside before they are degraded (Scott et al., 1993). The GAP analysis helps identify differences between information systems or applications. This tool provides the fundamental information necessary to pinpoint natural protected areas based on the distribution of registered reports through provinces and municipalities. Natural history collections in museums contain critical data that can be used for making important decisions about conserva- tion of biodiversity. Collectively these specimen data bases describe the distribution of a known taxon through a time and spatial span (Ponder et al., 2001). Flores-Villela (1993b), placed the Mexican herpetofauna in 10 natural regions defined by climate and vegetation type. Flores-Villela (1993a) described the distribution patterns of Mexico’s reptiles and amphibians, including areas of endemism and factors that generate this distribution. Flores-Villela and Gerez (1994) looked at the distribution of Mexican vertebrates, including reptiles, and reported 92 species of reptiles for the state of Jalisco. This article provides information on the patterns of distribu- tion and species richness for the state of Jalisco and the associ- ated vegetation types, physiographic provinces, altitudes, cli- mates and herpetological provinces. This analysis provides information as to the effect these factors have on the distribution of reptiles in the state. Furthermore, this analysis allows the identification of areas that are missing information and could be considered a priority for conservation. Study Site The state of Jalisco has a surface area of 78, 890 km ; it is 2 Figure 1. Map of the state of Jalisco and neighboring states. 1