Our friend Erin Moore at CONSERVATION NORTHWEST recently posted this article on the Flying Squirrel......One would not think this tiny creature to be an indicator species of forest health in the Pacific Northwest................Indeed, the dead snags and dense canopy cover these squirrels require to survive are beneficial for optimum diversity of livng creatures in forests across the Americas............a good read below!

The wisdom of flying squirrels


Posted by Erin Moore


We've always know that the northwest's favorite gliding mammal is dependent on underground mushrooms. Now, it turns out that flying squirrels have much to teach us when looking at ecological restoration of degraded forests.

A Macau casino mogul recently paid $330,000 for a pair of white truffles. But for northern flying squirrels, truffles really are priceless. They are the stuff of survival. The underground mushrooms make up 80% of what squirrels eat; vegetation makes up the other 20%: seeds, nuts, and lichens growing on trees. Unlike their cousins, flying squirrels don't cache food for wintertime, when lichens become particularly important food stuffs.,Truffles themselves are fascinating because they result from a symbiosis, or mutually beneficial living arrangement, with the smallest, most active tree roots. The fungi need trees and vice versa. Fungi in the form of mycorrhiza ('tree root' in Greek) get photosynthates (sugars and carbohydrates) made by plants, which gain nutrients, water, and some protection from the fungi.

Using a large flap of skin connecting front to hind legs, flying squirrels glide from tree to tree. This small squirrel weighs just 3 oz. They forage at night. They are fascinating because they themselves comprise a scrumptious 90% of the diet of the endangered spotted owl, the next link in the ecological food chain.

I was once in the woods participating in an eastern Washington bird count in the open forests north of Kittitas. Boxes had been put out on fence posts for blue bird nests. As I peered into one of these boxes, out launched a young flying squirrel, followed quickly by two siblings! The squirrels were using the bird box as a den.

Now, it turns out that flying squirrels have much to teach us when looking at ecological restoration of degraded forests. To learn more about squirrels in dryer, eastside Cascades forests, wildlife ecologist John Lehmkuhl, with associates from the PNW Research Station, live trapped 900 flying squirrels and radio collared a portion of them to monitor where they went and how far. They also rated squirrel habitat for food and denning resources. The study results have interesting implications for forest restoration. Squirrels need large wood above the ground with holes to den in, like tree snags, or sturdy, brushy platforms, like those formed by mistletoe. According to the study, in younger stands mistletoe serves when snags aren't available. Also important to flying squirrels are large trees with lots of lichen (dens and food), diverse understory plants for fruits and seeds (more food), and rotting logs rich in truffles (lots of food). (These fungi, remember, live on fine trees roots and those roots make their way into moisture rich downed wood. Most surprising in what the researchers found was this: Having enough canopy cover, not the age of the forest, was the single best indicator of good flying squirrel habitat. That makes sense, if you've ever, seen them glide gracefully from tree to tree. You can do just that with the video, below!It also turns out that mature and even young mixed conifer stands of trees on the eastside were equally good for squirrels -- providing they also had good canopy cover and large tree elements. This was surprising because old forests have long been considered essential to northern flying squirrel success and survival.

Lehmkuhl et al. note that flying squirrel habitat could be conserved in dry forest landscapes through patchy, or variable density, thinning, which mimics the results of mixed-severity fires. For flying squirrels, Lehmkul says, "It's important that there be some level of patchiness and diversity across the landscape." In ecological restoration thinning (something that Conservation Northwest is promoting on the Okanogan-Wenatchee NF and in the Columbia Highlands), it's important for flying squirrels and other wildlife that we enhance the canopy cover of trees in the forest and maintain big trees and woody debris to promote lichens and truffles and a richer, more diverse forest.