Fungi in the diets of northern flying squirrels and lodgepole chipmunks in the Sierra Nevada

Abstract

The diets of a fungal specialist, northern flying squirrel (Glaucomys sabrinus (Shaw, 1801)), and a dietary generalist, lodgepole chipmunk (Neotamias speciosus (Merriam, 1890)), were examined in the old-growth, mixed-conifer forest at the Teakettle Experimental Forest in California's southern Sierra Nevada. Spores of fungi were identified from fecal pellets collected from both species during spring and summer of 1999 through 2002. Frequency of fungi in the diets of both squirrel species was consistently high across all seasons and years of study. Overall, G. sabrinus diets contained about 30% greater richness and evenness of fungal taxa than N. speciosus diets. There were no seasonal differences in richness and evenness of fungal taxa in squirrel diets. Richness of fungal taxa in diets was positively correlated with hypogeous sporocarp biomass and rainfall from June through August for N. speciosus but not for G. sabrinus. Dietary overlap between G. sabrinus and N. speciosus was high with respect to the most frequently consumed fungal taxa, although Gautieria and Gastroboletus were consumed in greater proportions by G. sabrinus than N. speciosus. Our results indicate that in the southern Sierra Nevada both G. sabrinus and N. speciosus were frequent consumers of a similar, diverse assemblage of fungal taxa and that consumption was proportional to seasonal differences in availability. For the more strongly mycophagist G. sabrinus, however, diet had a greater proportion of select fungal taxa and avoidance of less desirable taxa.

Ecología trófica del jabalí europeo (Sus scrofa) silvestre en Chile

“…En nuestro estudio se detectó un máximo de ocurrencia en otoño, mientras que en Europa es en invierno (Genov 1981b, Herrero et al 2004. La micofagia es habitual en micromamíferos de bosques del hemisferio norte (Ovasaka & Herman 1986, Meyer et al 2005) como de bosques de Nothofagus en Sudamérica (Pearson & Pearson 1982, Meserve et al 1988. Los hongos son relativamente pobres nutritivamente (Fogel & Trappe 1978, Groenwall & Pehrson 1984 pero son importantes en la dieta de los micromamíferos debido a su abundancia y fácil acceso (Cork & Kenagy 1989).…”

Ecology ofGlaucomys sabrinus: Habitat, Demography, and Community Relations

“…Yet, relatively little resource overlap occurs because species segregate according to forest type (Carey 1989) or microhabitat Holloway and Malcolm 2006). In the southern Sierra Nevada (where small mammal communities are relatively depauperate), substantial dietary overlap of fungi occurs throughout the year between G. sabrinus and Tamias speciosus, the lodgepole chipmunk, particularly in frequently consumed taxa (Meyer et al 2005b). The American red squirrel (T. hudsonicus), which overlaps much of the northern and eastern range of G. sabrinus, and Douglas's squirrel (T. douglasii), in the Pacific Northwest (Hall 1981), likely share resources with G. sabrinus (Maser and Maser 1988;Pyare and Longland 2001b;.…”

Small mammals exhibit limited spatiotemporal structure in Sierra Nevada forests

“…Northern flying squirrels (Glaucomys sabrinus), for example, are more restricted by available soil moisture and presumably the resulting distribution of truffles (Meyer et al 2005;Smith 2009; see also Lehmkuhl et al 2006). The extent to which this characterizes other species is not clear.…”