Flying Squirrel Nests
| Overview North American flying squirrels employ several nest types, and typically will use several nest types during their lifetime. Individuals may use a nest just once or for much longer periods, depending upon factors such as availability, sex, time of year, predator avoidance, parasite load, disturbance, water infiltration, and other variables. Shelters that are employed during night forays, as "one-offs" during natal dispersion, or as diurnal denning sites are called refugia nests. Shelters that are used to raise young are called natal nests. Shelters that are employed by a number of related or unrelated individuals during winter months are called aggregate nests. As a rule, southern flying squirrels are somewhat less than fastidious when it comes to "bathroom behaviour", and will often soil their own nests. There is no evidence on record of this behaviour among northern flying squirrels. Southern flying squirrels will also take food into their diurnal denning nests, where this behaviour is not found with northern flying squirrels, although both employ the use of nocturnal refugia nests to consume foodstuffs. Materials used to make nests varies wildly and depends upon what suitable materials are present in a particular squirrel's immediate geographic location. These materials can include strippable bark (i.e. cedar, birch, wild grape); grasses; mosses; lichens; found animal fur; found bird feathers; small twigs; tree leaves (deciduous and coniferous); man-made materials (i.e. attic insulation, newspaper). Nest
depth, or loft, varies according to type of use required, season, and
sex of the nest builder. Below are two representative examples which
display the difference between a late spring natal nest (left) built by
a gravid female northern flying squirrel and a late spring dirunal refuge
nest built by a solitary male northern flying squirrel (right). This
natal nest is almost 700 percent larger by volume than the solitary
male nest. Additionally, the solitary male nest material has not been
finely shredded as is the case with the natal nest material, both of
which consist of (mostly) eastern white cedar bark.
Eastern white cedar tree bark, leaves and wood contain varying levels of water repellent oils and insecticidal oils (specifically thujone a -thujone, b -thujone and fenchone). These two important properties have not been overlooked by flying squirrels. In our area of study, (Grey and Bruce counties, Ontario, Canada), every single nest built by northern flying squirrels consists almost wholly of eastern white cedar bark (some cedar leaves are present in some nests. Also found in the nest material is sphagnum moss, grasses, fur, feathers and occasionally, twigs).  Typical natal nest (left) and solitary male nest (right) Scale shown is metric (mm/cm)  Some
native North American groups traditionally employed red and flying
squirrel nesting material as an absorbant lining for
diapers. Somehow we doubt Procter & Gamble will bring
a Squirrel Nest Pampers diaper to market!
|