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Information deficit constrains our capacity to assess the status of threatened species in regional and global contexts. In this study of the endangered Worthen’s Sparrow Spizella wortheni, we first review its current and potential distribution using the species distribution software, Maxent. An initial basic model was constructed using historical records, and used to guide a subsequent search for additional populations in summer 2013. Using the information gathered from our survey, we built a second, breeding model, to update the current and potential species distribution. Population size was estimated using line transects of variable length to count singing males and calculate densities per 10 ha. We found 10 new small reproductive populations dispersed south of the established core area, increasing the extent of occurrence of the species from 25 km2 to almost 17,000 km2. Suitable habitat across the species’ range was more than threefold higher in the breeding compared with the basic model. We counted 316 males, with a mean density of four individuals per 10 ha. Our results demonstrate that conservation assessment based on limited records can exaggerate the vulnerability of species, and confirm that the Worthen’s Sparrow population and geographic distribution range are larger than previously determined, indicating that the Red List status of this species should be reconsidered. The use of niche models was successful in enhancing species information data quantity (e.g. range extensions) and quality (e.g. more precise habitat requirements), facilitating improved understanding of needs and conservation status in the wild.

La caída de hojarasca y el contenido de macro (Ca, N, P, Mg y K) y microminerales (Fe, Mn y Zn) de las hojas se compararon en dos sitios durante 12 meses (septiembre 2008-agosto 2009). El sitio 1 se ubicó en la comunidad El Llano de La Soledad, Galeana, Nuevo León (1,863 m) y el sitio 2 en la comunidad San José del Alamito, Satillo, Coahuila (1,895 m). En cada sitio se colocaron, aleatoriamente, 10 canastas (1 m2) para la captura de hojarasca. La caída anual de hojarasca en el sitio 2 fue mayor (407 g·m-2·año-1) que en el sitio 1 (162 g·m-2·año-1). Las hojas representaron el 47.7 y 53.2 % en el sitio 1 y 2, respectivamente, seguido de ramas (24.6 y 20.3 %), estructuras reproductivas (21.3 y 20.2 %) y otros (4.3 y 7.6 %). La deposición de macro y microminerales fue mayor en el sitio 2 que en el sitio 1. Las diferencias espaciales y temporales, en la cantidad de hojarasca y el retorno de minerales, pudieron estar relacionadas con las temperaturas extremas, composición de la vegetación y propiedades químicas del suelo. ABSTRACT Litterfall and macro (Ca, N, P, Mg and K) and microminerals (Fe, Mn and Zn) components of the leaves were compared in two sites for 12 months (September 2008-Agust 2009). Site 1 was located in El Llano de La Soledad, Galeana, Nuevo León, Mexico (1863 m) and site 2 in San José del Alamito, Saltillo, Coahuila, Mexico (1895 m). A total of 10 litter traps (1 m2) were randomly located at each site to collect litterfall. The annual litterfall at site 2 was higher (407 g·m-2·year-1) than at site 1 (162 g·m-2·year-1). Leaves (47.7 and 53.2 %: site 1 and site 2, respectively) constituted the highest component, followed by branches (24.6 and 20.3 %), reproductive structures (21.3 and 20.2 %) and others (4.3 and 7.6 %). The deposition of macro and microminerals was higher at site 2 than at site 1. The spatio-temporal differences in litterfall and mineral return might have been related to the extreme temperatures, plant species composition and chemical soil

Background: Although the flora of the State of Nuevo León is well known, there are few records of ethnobotancial information. An ethnobotanical study was undertaken in order to know the medicinal plants used by people living at the scrublands and oak-pine forest areas in the southern Nuevo León. Collection of plants specimens and interviews were carried out among the people of the municipalities of Aramberri, Galeana, and Zaragoza. Since former studies in the region are scarce, the aim of this work was to record the medicinal species and their uses in the scrublands and oak-pine forest areas, of southern Nuevo León, Mexico, and also to know if there are differences in the number of species and number of uses knowledge by people. Methods: Field work was carried out over a 2 years period; useful plants were collected and a total of 105 people from 46 different villages were interviewed. A database was compiled using data collected by means of semi structured interviews. The data were analyzed by means of non-parametric statistics, using goodness-of-fit test (Chi-squared) (number of species known by people of each municipality, number of uses known by people of each municipality), Chi-squared modified to incorporate the Yates Correction (number of species known by people living at scrublands and oak-pine forest); the Kruskall-Wallis test (number of species known by women and men of the three municipalities), and the Spearman’s rank correlation coefficient (age and number of species known, and age and number of uses). Results: A total of 163 medicinal plant species were recorded in the study area, comprising 108 wild and 55 cultivated plants. A total of 117 species were recorded in the oak-pine forest, and 111 in the scrublands area, a total of 68 were recorded in both areas; 68 medicinal species are used in all three municipalities, 40 wild and 28 cultivated. We documented 235 different medicinal uses. The most common plant parts used for medicinal purposes were found

The aim of the study was to determine, seasonally, the nutritional value of the native shrubs: Acacia amentacea, Castela erecta, Celtis pallida, Croton cortesianus, Forestiera angustifolia, Karwinskia humboldtiana, Lantana macropoda, Leucophyllum frutescens, Prosopis laevigata, Syderoxylon celastrinum and Zanthoxylum fagara. Leave samples were collected seasonally during 2 years from Summer 2004 to Spring 2006 in three county sites: China, Linares and Los Ramones in the state Nuevo Leon, Mexico and evaluated for the content of their Crude Protein (CP), Neutral Detergent Fiber (NDF) and Acid Detergent Lignin (ADL). Dry Matter Digestibility (DMD) was also estimated. The CP content (range of total means = 13-22% dry matter) in most plants significantly varied among sites and seasons and between years. The same pattern occurred for NDF (40-55), ADL (8-22) and DMD (48-73). Celtis pallida had the highest nutritional value. However, due to their high CP and DMD and low NDF and ADL all studied plants in all sites, most seasons and years may be considered as good food sources for white-tailed deer.

The Ca, K, Mg, Na and P contents were determined, seasonally during 2 consecutive years in leaves of native browse plants such as Castela erecta Turp sp. Texana (Torr & A. Gray) Cronquist (Simaroubaceae), Celtis pallida Torr. (Ulmaceae), Forestiera angustifolia Torr. (Oleaceae), Lantana macropoda Torr. (Verbenaceae) and Zanthoxylum fagara (L.) Sarg (Rutaceae) that were collected from August 2004 to May 2006 in a semiarid and subtropical area of the State of Nuevo Leon, Mexico at three county (Los Ramones, China and Linares) sites which are grouped under a similar climatic pattern. Mineral contents were measured using an atomic absorption spectrophotometer with exception of P content that was estimated using a colorimeter. All minerals in all species were significantly different among years, sites and seasons and interactions were also significant. In general, plants at Linares site which historically registered the highest rainfall had higher mineral content followed by Los Ramones and China. Moreover, during the 2nd year, all plants species showed higher mineral content than the 1st year. Furthermore, during the Summer session, all plants species had higher mineral content followed by Autumn, Winter and Spring. Regardless of spatio-temporal differences, all plant species had suitable levels of Ca, Mg and K to satisfy range domestic and wild ruminant requirements. In contrast, P and Na contents showed marginal inadequacies in some seasons throughout the year. Seasonal variations in minerals could be associated to climatic conditions like excessive irradiance levels during Summer and extreme low temperatures in Winter and rainfall events.

Se realizaron observaciones sobre los sucesos de temporada reproductiva de Spizella wortheni, se capturaron, midieron y marcaron ejemplares de la especie y se hicieron observaciones de individuos usando radiotelemetría. Se realizó una búsqueda intensiva de nidos, se evaluó el microhábitat de cada nido encontrado y se hicieron observaciones de cuidado parental en un nido activo. Los resultados sugieren que el área de estudio cumple con las condiciones necesarias para sostener poblaciones reproductivas de la especie, sin embargo las prácticas de pastoreo y uso de suelo en la zona pueden estar afectando el éxito reproductivo del gorrión de Worthen.