The Prince of Wales flying squirrel (Glaucomys sabrinus griseifrons) is a subspecies of the northern flying squirrel endemic to Prince of Wales Island and a few neighboring islands in the Alexander Archipelago of Alaska.
Taxonomy
This subspecies is genetically distinct from the mainland northern flying squirrel, according to evidence found in mitochondrial DNA and microsatelite data.
Description
It has a unique coloration compared to other subspecies of the northern flying squirrel. It is whiter on the ventral side, darker on the dorsal side, and the head/neck area tend to be more gray than other subspecies. Adults are usually around 25-37 centimeters in length and 110-230 grams in weight.
Habitat and range
The distribution history of G. s. griseifrons is unknown, but the subspecies probably colonized Prince of Wales after the last glacial maximum during the Holocene epoch. Sitka spruce (Picea sitchensis) and western hemlock (Tsuga heterophylla) are the primary habitat for G. s. griseifrons, due to their association with old growth forests of the area.
Ecology
This subspecies is often considered a keystone species in the Southeastern Alaska area because it consumes and disperses conifer seeds and fungal spores into areas with little vegetation and sites of disturbance. The released fungi spores aid in the absorption of nutrients by plants and speed up regrowth in these areas. The American red squirrel tends to be the biggest competitor for resources for mainland populations of the northern flying squirrel. However, the American red squirrel is not found on the Prince of Wales islands, allowing the Prince of Wales flying squirrel does not have any major competitors.
Predation and disease
This subspecies has not been found to have high predation rates. Predators of these flying squirrels include raccoons, Pacific martens, and probably barred owls. The raccoon population on the island is small, and therefore most likely does not have a large impact on the flying squirrel population. Studies have shown that flying squirrels only make up about 5-7% of a marten's diet. A recent Prince of Wales inhabitant, the barred owl, likely predates on the flying squirrels, but there are no studies suggesting this. Humans have not been known to hunt this subspecies. Disease has not been shown to be a limiting factor in population growth. Currently any disease that may be affecting these squirrels is unknown.
Diet
Glaucomys sabrinus griseifrons have a generalized diet and can be considered mostly herbivorous, primarily eating fungi, lichens, green vegetation, berries, seeds and insects They have also been observed eating meat, young birds, and eggs. G. s. griseifrons is suggested to be more generalized in its diet than other subspecies of northern flying squirrels.
Reproduction
The Prince of Wales flying squirrel is a r-selected species. They start breeding around one year old, or sometimes older, and usually have one litter each year of 1-6 young, averaging 2-4. Mating seasons tend to be around February through July, and the mothers will nurture them inside dens. The males do not play in a role in taking care of offspring. Infants take around five weeks after birth to become almost fully developed. After around ten weeks, they are able to glide and leap, and are ready to leave their mothers. Flying squirrel longevity can reach up to seven years old in the wild. From this, annual survival rates are suggested to be fairly high.
Behavior
Despite its name, flying squirrels do not actually fly. They glide using a flap of skin called a patagium. Since they are arboreal mammals, they spend most of their life in old growth temperate rain forests in the high canopy. They are a non-migrating species and typically stay near areas in which they were born. They are active all year, even in the winter, because they do not hibernate. During cold weather in the winter, they huddle together to conserve heat. Groups as large as ten individuals have been documented. They are nocturnal with greatest activity right before dawn and right after dusk. They rest in dens during inactive times. They have a strong olfactory sense that helps them to detect food. The Prince of Wales flying squirrel tends to utilize dens in tree cavities or snags for storing food, hiding from predators, and reproduction. They do not spend much time on the ground in order to avoid predation. Northern flying squirrels are considered to be one of the most aerodynamic of mammals with the ability to travel between 3 and 45 meters in one glide. They travel between the trees to feed and in search of dens.