Resumen
This dataset contains records of food availability and diet of rodents in habitats at different elevations (1700 m, 2300 m, 3100 m above sea level) and seasons (winter and summer) in the Manzano Histórico-Portillo de Piuquenes Reserve, Mendoza, Argentina. Regarding food availability, the dataset includes information on plant richness, diversity, and cover, as well as arthropod morphospecies richness, diversity, and abundance. Additionally, it provides details on the dietary composition of each rodent species across elevations and seasons. At a coarse scale, the dataset presents the frequency of consumption of trophic items grouped into three categories based on their nutritional quality: vegetative parts (leaves and herbaceous stalks, lower nutritional quality), seeds (intermediate quality), and arthropods (high quality). At a fine scale, the dietary composition identifies the genus (and in most cases the species) of all plant items consumed.
Métodos
Sampling was conducted from 2017 to 2019 in months of low ambient temperature (July and August; i.e., winter) and in months of relatively high temperature (November to February; i.e., summer). Food availability is described by plant richness, diversity (Shannon-Wiener index), and cover, as well as arthropod morphospecies richness, diversity, and abundance for each elevation-season combination (i.e., 1700 m-summer, 1700 m-winter, 2300 m-summer, 2300 m-winter, 3100 m-summer). For plant sampling, we used the point-quadrat method. In each elevation-season combination, we randomly established 9-10 lines of 30 m length, over which we recorded at 30 cm intervals each plant species intersecting that line. For arthropod sampling, we set 14 pitfall traps per elevation-season combination that were kept active for 3 days and 3 nights. Each trap consisted of jars (325 cm3) half-filled with water and a few drops of detergent to reduce surface tension. All arthropods captured were counted and classified into morphospecies using only external morphology without the use of keys. Rodent diet data were obtained from fecal samples of Phyllotis vaccarum (Punta de Vaca leaf-eared mouse), Abrothrix andina (Andean soft-haired mouse), Akodon oenos (Monte grass mouse), and Euneomys sp. (chinchilla rats). In the study area, P. vaccarum was captured at all sampling sites, i.e., at 1700 m, 2300 m and 3100 m asl. In contrast, A. andinus was found only at 2300 m and 3100 m, A. oenos was only recorded at 2300 m, and Euneomys sp. was captured exclusively at 3100 m. Fecal samples were collected from individuals immediately after capture. Subsequently, they were analyzed in the laboratory to identify histological characteristics of leaf epidermis, seed coats, and arthropod body parts. Each sample was examined under a microscope at 40× magnification, analyzing up to 50 random fields per slide (in some winter samples, this number was lower due to limited fecal material). The frequency of each dietary item was determined as the proportion of fields containing the item out of the total fields observed. Plant items consumed were identified to the genus level (and to the species level in most cases) through comparisons with reference material. Dietary items were grouped into three categories based on their nutritional quality: vegetative parts (leaves and herbaceous stalks, lower nutritional quality), seeds (intermediate quality), and arthropods (high quality).