Mycophagy in Botta's Pocket Gopher (Thomomys bottae) in Southern Oregon

Our goal was to determine whether Botta's pocket gopher (Thomomys bottae) eats hypogeous oak-woodland fungi and potentially functions as a vector of mycorrhizal inoculum. Although field guides and species accounts describe T bottae as strict herbivores, members of the family Geomyidae are possible vectors of mycorrhizal inoculum because many ectomycorrhizal fungi are hypogeous, fruiting underground where Geomyidae live. Some studies have documented that Thomomys species are mycophagous at least seasonally. We removed fecal pellets from the large intestines of three T bottae trapped in the spring at Whetstone Savanna in southern Oregon and examined them for presence of ectomycorrhizal fungal spores. Using light microscopy, we found spores from eight genera of hypogeous ectomycorrhizal fungi associated with Quercus garryana. These findings confirm that T bottae is mycophagous and support a role for T bottae as a spore dispersal vector for oak-obligate fungi. Therefore, T bottae is potentially important for the survival, woodland regeneration and range expansion of Q. garryana.