Inhabitant changes in long-term mole nesting at the same site, revealed by observing mushroom fruiting at the site

Talpine moles are reported to nest at the same site for periods longer than their known longevity. The present study verifies experimentally in situ that during such long-term nesting, the inhabitants of the nest change, with the new inhabitant constructing its own nest if the existing nest has been removed. The principal methods involved removal of both the nest and inhabiting mole from the nesting site, the site that had been located by observing the fruiting of the mushroom species Hebeloma radicosum. This treatment was followed by observation of refruiting of the mushroom at the same site; refruiting indicated renesting by another mole. Verification was made at three sites in the cool temperate forests of central Japan where three talpine species live. At two of the sites, the inhabiting Euroscaptor mizura mole was replaced by another E. mizura mole. At the third site, a Mogera wogura mole was replaced by a Mogera imaizumii mole. The causes and circumstances for such persistent nesting are discussed, with emphasis on habitat-cleaning symbiosis.