Dieta de Peromyscus difficilis (Rodentia: Muridae) en un bosque templado en el Parque Nacional Desierto de los Leones, D.F.
Along 10 months (October 2013-July 2014) the stomach content of 59 Peromyscus difficilis specimens was examined. Samples were collected in an Oyamel and broadleaved trees forest called “Paraje San Borja” which is part of Mexico City’s National Park "Desierto de los Leones" (PNDL). The samp...
| Autor: | |
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| Tipo de recurso: | tesis de maestría |
| Estado: | Versión publicada |
| Fecha de publicación: | 2015 |
| País: | México |
| Institución: | Universidad Autónoma Metropolitana |
| Repositorio: | Repositorio Institucional de la UAM Iztapalapa |
| Idioma: | español |
| OAI Identifier: | oai:bindani.izt.uam.mx:mg74qm60n |
| Acceso en línea: | https://doi.org/10.24275/uami.mg74qm60n |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/LEM/Desierto de los Leones (Ciudad de México) -- Muridae info:eu-repo/classification/LEM/Desierto de los Leones (Ciudad de México) -- Múridos info:eu-repo/classification/LEM/Forests -- Mexico info:eu-repo/classification/LEM/Bosques -- México info:eu-repo/classification/cti/2 |
| Sumario: | Along 10 months (October 2013-July 2014) the stomach content of 59 Peromyscus difficilis specimens was examined. Samples were collected in an Oyamel and broadleaved trees forest called “Paraje San Borja” which is part of Mexico City’s National Park "Desierto de los Leones" (PNDL). The sampling allowed evaluating three pluvial seasons in the area´s rainfall patterns: Due to meteorological phenomenon "El Niño", from October to December 2013, was atypically a rainy season. January to April 2014 was a dry season. The period from May to July was also a rainy season. Micro-histological techniques allowed identifying 40 components of three different taxa: plants (20 taxa), fungi (14 taxa) and insects (6 taxa); as well as 52 vegetal food items (13 stems, 12 leaves, 11 flowers, 6 grain pollen, nueve fruits and one seeds). The P. difficilis food items consumption average per day was: 2.4 stems, 1.6 fruits, 1.5 flowers (pollen), 1.08 leaves, 1.5 insects and 1.7 fungi. The entire sampled specimen consumed plants, and the vegetable diet components allowed to record 2 Divisions, 11 Families, 18 Genus and 16 species and also 2 morpho-species. In order of importance stems, fruits, flowers, pollen and leaves were the most consumed. Among the plant taxa that prevailed the following were found: Rosaceae, Asteraceae and Berberidaceae stems; Rosaceae and Asteraceae fruits; Laminaceae and Rosaceae flowers; A. religiosa (Pinaceae) pollen; morphospecie 1 and Rosaceae leaves. The consumption of herbaceous grasses and dominant shrubbery in the underwood forest of the site underpinned. This consumption varied seasonally according to rainfall patterns, accessibility and resources availability, especially according to its phenology A 94% of the individuals consumed insects, prevailing Coleoptera, Diptera and Lepidoptera along the year, while Hymenoptera and Orthoptera were also found in some seasons, as well as fragments of unidentified insects. A 52% of individuals that consumed fungi included 14 macrofungi taxa, representing Ascomycota and Basidiomycota Subdivisions. Three Families and four Genera were determined for Ascomycota and eight Families, four Genera and two species for Basidiomycetes. All fungi were consumed during the rainy season, except for a Pezizaceae Family (Ascomycota) truffle, which may belong to Pachyphloeus sp., that is frequently found in the roots of trees such as Oyamel (A. religiosa, Pinaceae). The consumption of taxa and food items was different according to resources availability and rainfall patterns change. Therefore, the content of the diet changed along the year. Although there was a considerable overlap in the components of the diet, males, females, even young and adult individuals consumed several taxa and items. Similarly, the reproductive activity showed to have an effect on the content of the diet in males and females. This refuses the null hypothesis and supports the alternative hypothesis of the effect of gender, age and reproductive status affecting what P. difficilis consumed during the different pluvial seasons. Although P. difficilis reproductive activity presented all along the year in PNDL, females (pregnant and lactating) activity reached a peak during the rainy season autumn-winter and spring-dry, while males first peak matched the females’ peak (November 2013). The second male’s peak occurs during dry-cold season (February 2014). The behavior of the reproductive activity peaks for both sexes, happened from 2014 dry season to 2014 rainy season, preceded by a temperature increase at the site. The underwood habitat of Oyamel and broadleaved trees forest on the PNDL, provides an important diversity of plant and food resources including fungi and insects that are part of the diet of P. difficilis, allowing a mixed diet with a high digestible energy intake, full filling in this way the energy and nutritional needs, according to gender, age and reproductive activity of individuals. The results of this study, support that P. difficilis is a 'moderate generalist' specie in the trophic niche, consuming food resources available in three different taxonomic groups according to spatio-temporal accessibility, regarding mainly taxa and items (phenological changes) that are only present in certain environmental conditions, while also shows consumption recurrence of certain taxa and items always offered this habitat. Previous research is not enough to determine the Peromyscus genus diet in mixed template forests of Mexico and particularly for P. difficilis. The results obtained here about the diet of a population of this species that lives in a suburban forest of Mexico City, as is the PNDL allow quantitatively validate that the other components of the diet are different along the year, and that changing environmental conditions, as well as the composition of the diet of P. difficilis between these groups also changed level taxa, taxa and vegetable food items. P. difficilis consume of a considerable number of plant taxa, and different parts of them have probably a big effect on the distribution and population dynamics of these plants in the underwood forest. Therefore, it is possible that P. difficilis, is acting as seed and pollen dispersers and contributing as shaper, or builder, of the composition and structure of microhabitats at different spatiotemporal levels in the food web. The information generated in this assessment, is suggested as a guideline to aid the achievement of not only ecological, but also multidisciplinary studies on the biology and interactions of the species and their habitat. It is expected that similar research contributes to establish management and conservation plans and programs for temperate forests in the conditions of the PNDL, as a protected natural area, in a megalopolis like Mexico City. |
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