And the widely spaced trees give them lots of room to move and escape predators. Older-growth forests also supply large enough trees for nest cavities where these animals raise their young. In younger forests, flying squirrels are forced to nest in ground cavities amongst tree roots where they have little protection from weasels. So, older growth forests are critical, not only for flying squirrels, but also for marten, pileated woodpeckers, owls, and plants. Flying squirrels eat truffles.
Truffles are the underground fruits of some types of fungi.
These fungi attach themselves to the tips of tree roots and help the roots to absorb nutrients from the soil. So without truffles, trees may grow more slowly and may become more susceptible to disease. So every time a squirrel eats a truffle, it helps plant more truffles and keep trees healthy and growing well. Today, our natural older-growth forests are being cut and replaced by tree plantations made of single types of trees. Thus we risk losing about 25 species of birds and mammals which depend upon older-growth forests for their survival.