Aberrant plumages in Mexican birds are rarely documented; in this work we report a record of partial leucism in the House Sparrow (Passer domesticus) in Cd. Victoria, Tamaulipas, Mexico. We discuss on the low incidence of this phenotypic alteration

La distribución geográfica de la tángara azul-gris (Thraupis episcopus) en hábitats modificados antropogénicamente en MéxicoResumen. Mediante trabajo de campo, la revisión de bases de datos biológicos e información de la distribución geográfica histórica y actual de Thraupis episcopus se establecieron nuevos registros de anidación en el noreste de México y su ampliación hacia hábitats modificados por actividades humanas en la península de Yucatán y el noreste de México. Además, se evaluó si existía preferencia de la especie por hábitats conservados vs. modificados, por medio de un análisis de escenarios de cambio de uso de suelo de 3 décadas diferentes (1970, 1980 y 1990), obteniendo porcentajes de presencia. Se encontró que no existe una diferencia significativa entre preferencias de hábitat a través del tiempo.Palabras clave: tángara azul-gris, áreas urbanas, registros de anidación, cambio de uso de suelo, expansión geográfica, este de México.Abstract. We analyzed the historical and current distributional range data of the Blue-gray Tanager, and reported new nesting records in northeastern Mexico. We also assessed the range extension of this species into human-altered habitats in the Yucatán Peninsula and northeastern Mexico, based both on records from fieldwork and biological databases. We identified habitat preference (conserved vs. human altered) using land use change scenarios from 3 decades (1970, 1980, and 1990) and percentages of occurrence in a multitemporal approach, finding no significant differences in habitat use through time.

Updated information on the geographic and taxonomic representativeness of mammal specimens deposited in 28 Mexican mammal collections, the Mammal Networked Information System (MaNIS), and the Unidad de Informática para la Biodiversidad (UNIBIO) data bases were compiled in order to analyze and compare the overall current status of the specimens of Mexican mammals deposited in collections in North America. A total of 421,466 specimens deposited in 120 collections were documented, of which 233,116 were deposited in collections in the United States of America and Canada, and 188,350 in collections in Mexico. The collections with the greatest number of specimens from Mexico are the Colección Nacional de Mamíferos (CNMA 46,000), the University of Kansas (KU 44,301), and the Escuela Nacional de Ciencias Biológicas (ENCB 43,985). In Mexican collections, the states of northern Mexico are improperly represented in number of specimens (< 3,000), whereas in foreign collections, the states of central Mexico are poorly represented. The Mexican states better represented by number of specimens (> 10,000) are Baja California Sur, Chiapas, Oaxaca, Puebla and Veracruz. The orders better represented in terms of number of specimens are Rodentia and Chiroptera (234,978 and 120,956, respectively). The Mexican states with the smallest area have the greatest density of specimens collected (specimens/km 2 ), such as Distrito Federal (3.2), Tlaxcala (1.4), Colima (1.06), and Morelos (0.9). The aim of this analysis is to provide a baseline to establish appropriate strategies to complete the Nota del editor. Por considrar extensas las direcciones postales se decidio mandarlas al final de este articulo

Interspecific interactions among tropical mesocarnivorous species and other mammalian trophic guilds have been poorly studied, despite they have important implications in the survival, structure, demography, and distribution of these species. In this study we analyzed spatio-temporal interactions of three sympatric mesocarnivores that are located in the Northeastern limit of their geographic distribution in Mexico, with the objective of analyzing if these species coexist or compete in the axis of the temporal and spatial niche. With a sampling period from January 2015 to December 2016 and 26 camera-trapping stations (with in a set of two camera traps opposite to each other) and located along roads and animal trails, we determined the activity pattern and habitat use of L. wiedii (margay), L. pardalis (ocelote) y P. yagouaroundi (yaguarundi). All independent photographs of each species were grouped into three temporal categories (day, night and twilight) and six habitat categories; Oak Forest, Oak-Pine Forest, Cloud Forest, Pine-Oak Forest, Tropical Deciduous Forest and Medium Forest. Temporal and spatial overlap between species (i.e interactions) was obtained with the Czekanowski index and the Pianka index, respectively. These indices are symmetrical and take values from zero to one, where the results close to zero indicate that there is no overlap between species and values close to one indicate overlap. We obtained a total of 379 independent photographs, of which 239 corresponded to margay, 118 to ocelot and 22 to yaguarundi. Margay and ocelot were nocturnal, with 75 % of their records in this category showing a high temporal overlap (0.85); whereas yaguarundi was fully diurnal, suggesting it may be able to coexist with the other two species (margay and ocelot). Moreover, the yaguarundi used habitat similar to ocelot and margay (with high spatial overlap of 0.81 and 0.72, respectively), while the spatial overlap between the margay and ocelot was intermediate (0.53), since they used in most cases different habitat types. Our results suggest that there is no interspecific competition among these tropical mesocarnivorous species, probably due to antagonistic interactions among them on the temporal and spatial axis. These strategies may positively favor populations of mesocarnivores, which are characterized by having a high territorial behavior.

Reportamos el primer ejemplar de la tángara ala amarilla (Thraupis abbas) colectado en un área urbana de Tamaulipas. Asimismo, aportamos una compilación de registros observacionales históricos y recientes que muestran una expansión en el uso de hábitat y la distribución geográfica de la especie en el noreste de México.