Winter 2006

Table of Contents

Northern flying squirrel.

The Habitat Puzzle
by Kevin Mack, PAWS Wildlife Naturalist

(Editor’s Note: This article is from the newsletter of the Progressive Animal Welfare Society (PAWS) of Lynwood, one of WDFW’s licensed wildlife rehabilitators.)

Several weeks ago, I was standing in an Edmonds backyard at dusk, watching for bats to emerge in the fading light. I turned toward the south, and my view of the sky was framed by the silhouettes of two tall fir trees that stood about 50 feet apart. It was a warm, clear night, and the sky that was visible in between the two trees was just light enough that a hint of blue could still be detected. Conditions were perfect for viewing nocturnal flying mammals.

As I stood and gazed upward, a slight movement near the top of the tree on the left caught my eye. A small, oblong shape shot out from among the fir branches. Just as it began to fall, the object seemed to stretch and flatten, forming a rough rectangle. The object's descent slowed, but it maintained its forward momentum, moving diagonally downwards toward the fir tree on my right. As it passed in front of me, I could make out a rounded projection at the front of the rectangle, and a long, narrow extension that trailed behind.

It was too dark to see anything in great detail, but I had the distinct impression that the surface of the object was fuzzy. It continued on its trajectory and disappeared into the branches midway up the fir tree on my right. The whole event lasted three seconds at most, and my brain was still processing the visual input when I heard the words "flying squirrel" escape from my mouth.

The realization that I had just seen a Northern Flying Squirrel was exciting. Although they are fairly common in forested areas, these shy, nocturnal creatures are seldom seen by humans. I should not have been surprised to learn that flying squirrels were living in this Edmonds neighborhood. I had seen members of this species come in to PAWS from areas as urban as the Northgate neighborhood in Seattle.

Still, catching that brief glimpse of the flying squirrel as it moved from one tree to the next immediately changed my perception of both the property on which I was standing and the neighborhood as a whole.

Without moving at all, I had been pulled out of a backyard, and transported into the middle of Northern Flying Squirrel habitat. The yard in which I made my observation certainly had several habitat features that would appeal to flying squirrels. In addition to the fir trees between which I had seen the squirrel glide, there were a few medium-sized cedars in the front yard, and two tall cedars, another fir, and a small apple tree in the backyard. All of the trees were easily within gliding distance of one another. In addition, the cedars and firs had many branches that were covered in lichen, a favorite food of the flying squirrel. Although they get most of their water from the foods they eat, the property also had two bird baths from which the squirrels could drink if the need arose.

Despite the positive features of the property, however, it had one huge drawback: it was far too small to support a viable population of Northern Flying Squirrels. Why then was a flying squirrel spotted on the property?. Because to the squirrel, the small property was just one part of a much bigger area of suitable habitat.

A quick glance at the properties adjacent to the one on which I had seen the flying squirrel revealed that they were all very similar in composition. All had a few large trees and other attributes that made them suitable for Northern Flying Squirrels. In fact, I could follow a relatively dense line of trees for many blocks. Even where there were busy roads, tall trees on either side of the road made safe flying squirrel passage possible.

Through human eyes, each individual property was separated by various styles of fencing. But there would clearly be no separation in the eyes of a flying squirrel who would be traveling through the treetops high above these human-created delineations. To a flying squirrel, the whole area would be just another forest.

Every small piece of property in that neighborhood was part of a larger habitat puzzle. Although the owners of the properties hadn't planned it that way, resources on their land were arranged in a pattern that was appealing to Northern Flying Squirrels. The placement of trees on adjacent properties created a perfect corridor along which the squirrels could move in safety. Although the properties would be of little value to the squirrels as isolated islands of habitat, in this connected setting, every single property was essential.

So what would happen if the owners of a single property in this neighborhood decided to clear their trees? Depending on where the property was situated, this could have serious consequences for the habitat puzzle that I have just described.

Any removal of trees would likely reduce the total available habitat, and in turn reduce the number of flying squirrels that the area can support. If the property contained a concentration of food resources, appropriate nesting sites or other essentials, the impact of its loss would be even greater. In addition, a cleared property may act as a barrier to movement of the squirrels if it creates a large enough gap in their travel corridor.

As with a jigsaw puzzle, the more pieces that are removed, the harder it is for the audience to identify the picture. Remove too many small sections of habitat, and the flying squirrels may no longer identify the area as a suitable place to live.

Just as removing small sections of habitat may have negative effects on the flying squirrels, adding small sections may have extremely positive effects. Planting appropriate trees on a formerly treeless property will serve to increase the available habitat, and may create a connection between two formerly non-contiguous patches of habitat. Even a relatively small piece of property may provide the crucial missing piece in the larger habitat puzzle.

This is why, no matter how small or large your property is, landscaping for wildlife can make an enormous difference to the animals that share your space.

Whether you have a tenth of an acre or 10,000 acres, your property is a piece of this larger habitat puzzle, and how you manage that property can make all the difference for the wildlife around you.