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Ortiz-Serrato L.,Autonomous University of Baja California | Ruiz-Campos G.,Autonomous University of Baja California | Valdez-Villavicencio J.H.,Conservacion de Fauna del Noroeste
Western North American Naturalist | Year: 2014

We studied the diet of the exotic American bullfrog (Lithobates catesbeianus) in Arroyo San Carlos, located in northwestern Baja California, Mexico, during spring and summer 2009. Analysis of 64 stomach contents revealed 15 prey types, of which the exotic red crayfish (Procambarus clarkii) and terrestrial isopods (Armadillidiidae) were the most significant items (according to an index of their relative importance), making up 64% and 31% of the bullfrog's diet, respectively. Diet differed between the sexes, with red crayfish eaten more frequently by males (84%) than females (69%). Bullfrog diet changed with body size, with smaller individuals (≤86 mm) containing woodlice (61%) as the dominant prey type and larger individuals (≥129 mm) containing red crayfish (97%) as the dominant prey type. The average prey size consumed was significantly correlated with body length.© 2014. Source

Valdez-Villavicencio J.H.,Conservacion de Fauna del Noroeste
Southwestern Naturalist | Year: 2014

The African clawed frog (Xenopus laevis) is an invasive amphibian in at least 15 countries. In Mexico, only occasional records have documented it in the state of Baja California. In May 2013, we discovered a population at Puente el Morro in Rosarito. In a 1-h session of trapping, we captured 106 individuals (adults and juveniles) at a small pond. We did not see eggs, tadpoles, or reproductive activity, but lengths of frogs indicate that some have reached sexual maturity. This discovery indicates the need for conservation plans and action against X. laevis dispersion, especially in Mediterranean zone climates. © 2014, BioOne. All rights reserved. Source

Valdez-Villavicencio J.H.,Conservacion de Fauna del Noroeste | Peralta-Garcia A.,Conservacion de Fauna del Noroeste | Hollingsworth B.D.,San Diego Natural History Museum
Check List | Year: 2015

A new population of Ensatina eschscholtzii klauberi in the San Quintín volcanic field, Baja California, represents the first coastal population of this taxon. This record extends the range ca. 71 km southwest of the southernmost record of E. e. klauberi in the Sierra San Pedro Mártir and represents the first population discovered outside of coniferous and pine-oak woodlands. © 2015 Check List and Authors. Source

Martinez-Solano I.,Institute Investigacion en Recursos Cinegeticos CSIC UCLM JCCM | Martinez-Solano I.,University of Connecticut | Peralta-Garcia A.,Conservacion de Fauna del Noroeste | Jockusch E.L.,University of Connecticut | And 3 more authors.
Molecular Phylogenetics and Evolution | Year: 2012

Inferences about species boundaries and evolutionary history are often complicated by discordance between datasets. In recent times, considerable effort has been devoted to understanding the causes of discordance between the patterns of genetic variation and structure shown by different unlinked molecular markers. The genus Batrachoseps (Caudata, Plethodontidae), the most diverse group of salamanders in western North America, is characterized by limited morphological variation and discordance between molecular datasets, making it a challenging group for taxonomists but also a good model to test newly developed analytical methods to sort out possible sources of discordance. In this study, we present a comprehensive assessment of the evolutionary history of B. major, one of the most widespread species in the genus, based on extensive sampling and phylogenetic and coalescent analyses of data from mitochondrial and nuclear markers. We found non-monophyly of mtDNA in B. major, with two lineages (northern and southern) that are more closely related to other species in the genus than to each other, but this division was not apparent in nuclear DNA. Despite non-monophyly in gene trees, species tree analyses recovered a sister group relationship between the two lineages of B. major, and coalescent simulations suggested that there is no need to invoke gene flow to account for the discordance across gene trees. The possibility that these two lineages represent sister, cryptic taxa, is discussed in the context of Bayesian methods of species/lineage delineation. Contrary to prior expectations, B. major has experienced extensive diversification on the Baja California Peninsula, where four endemic lineages have persisted for at least 4 million years. © 2012 Elsevier Inc. Source

Valdez-Villavicencio J.H.,Conservacion de Fauna del Noroeste | Peralta-Garcia A.,Conservacion de Fauna del Noroeste | Guillen-Gonzalez J.A.,Gestion Ambiental y Desarrollo
Revista Mexicana de Biodiversidad | Year: 2016

We report a new population of the southwestern pond turtle Emys pallida in Baja California. This record represents a range extension of 95.5 km south from the nearest reported location. Also represents the only oasis population within the Central Desert ecoregion in Baja California. © 2016 Universidad Nacional Autónoma de México, Instituto de Biología. Source

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