[Tweeters] Flying Squirrel Results

David Hutchinson flora.fauna at live.com
Sun Oct 27 15:25:51 PDT 2013

First thanks to the many people who took the time to respond to my request for information on these local treasures. I trolled several govt. websites in the quest for answers, but you, the public proved more helpful.

When I first moved to Seattle in the late 70s, people still talked about Flying Squirrels as regularly occurring in parks like Seward and Lincoln, probably in Carkeek and Camp Long and perhaps even occasionally in Discovery Park. While it is no coincidence that most of these parks have stands of coniferous trees, govt. websites state that these critters also occur in mixed forest stands and can do well in young forests over 35 years., the latter surely forest industry related research.

Matters have changed quickly and according to you Tweets, there has been no evidence of Flying Squirrels in Seattle Parks for at least ten years. The last report from Marymoor, from a nest box, is also ten years old.

A little further south, it turns out, there are still park-related populations. Flying Squirrel still occur in good numbers at Phantom Lake, Robinswood, Kelsey Creek, Lewis Creek, Mercer Slough, Cougar Mountain, Beaux Arts Village, the greenbelt just west of W. Lake Sammamish Pkwy and one in a nest-box on Mercer Island not so long ago.Though I do not know these sites, presumably they have good acreage of coniferous forest.

While it would be easy to say that the Seattle Parks' decline is due solely to the rapid spread of the Barred Owl, they surely must be taking their toll. One research paper had evidence that Spotted Owls take 25% of the Flying Squirrels in their territory and one would guess that Barred Owls must take at least as much as they replace Spotted Owls or move into empty urban and suburban niches. But while surely there is a healthy Barred Owl population in all the Eastside suburban parklands, yet the squirrels continue to do well.

Other factors must be involved, perhaps patch size and/or forest structure to depopulate Seattle's parks. One consideration, in somewhere like Discovery Park, is that our deciduous canopy of Red Alder and Big-leaf Maple is becoming senescent and is thinning out.Another is the "landscape trap" effect, where the weight of long-term disturbance and loss of topsoil allows for no natural regeneration of conifers. Ironically, in healthier forest stands that is an issue where Flying Squirrels might help. They eat a lot of things, but a favourite is fungus of different types: some are harvested from the forest floor, other micorrhizae are dug up from below ground and then their spores trans-located by the squirrels. And these are the very items which help sustain a healthy conifer forest.

A habitat restoration buddy suggested that Marbled Murrelet should be the target species when considering the very long-term goals for re-establishment of native forests in Seattle Parks. Seems though that maintaining a forest a Flying Squirrel could call home is an essential part of that process.Thanks again to the Tweets who contributed.

David Hutchinson, Owner
Flora & Fauna: Nature Books
Discovery Gardens: Native Plants
Forest Restoration Steward
Discovery Park

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