Cached fungi in non-native conifer forests and their importance for red squirrels (Sciurus vulgaris L.)

The caching of fungi by red squirrels Sciurus vulgaris was investigated in commercial conifer plantations by walking transects in Kielder Forest, Cumbria and Wauchope Forest, Scotland. In 11 transects, a total of 58 fungal fruiting bodies were observed on branches in trees, consisting of four different species (49 Russula ochroleuca, seven R. metica, one R. vesca, one Colybia maculata). Fungal stores were found to be short lived and most fruiting bodies cached were gone after 2 weeks. Based on the survey findings we estimate that within an average red squirrel home range there would be a minimum of 42 cached fruiting bodies, constituting a food store of approx. 525-714 kJ.