Red giant flying squirrel

Appearance

The red giant flying squirrel is among the largest flying squirrels and longest squirrels. It has a head–and–body length of 28.5–55 cm , tail length of 34–63 cm and weighs about 990–3,200 g . Within each region, males are generally somewhat smaller, at least in weight, than females.

It varies considerably in appearance depending on subspecies and location. Roughly, it can be divided into the following subspecies groups, some of which variously have been regarded as part of this species, the Indian giant flying squirrel, the red and white giant flying squirrel or the spotted giant flying squirrel, or their own separate species. Up until the 1980s, some authorities even listed the Indian giant flying squirrel itself as a subspecies of the red giant flying squirrel.

Behavior

The red giant flying squirrel is largely nocturnal, starting its activity just before dusk and retreating at dawn.

On occasion it may stay out until the mid-morning. The day is typically spend in a hole in a tree that is 10 m or more above the ground, although sometimes in rock crevices or a nest made of vegetation in a tree instead.

In a study of seven nests in India's Namdapha National Park, one tree hole was c. 35 m above the ground, while the remaining were between about 15 and 21 m above the ground. Red giant flying squirrels and hornbills sometimes compete for the same tree holes. Densities vary greatly in the red giant flying squirrel. In Taiwan ''grandis''), it varies from an average of around five animals per 20 ha in hardwood forests to around one-fifth that density in conifer plantations, although there are also reports of home ranges in the latter habitat that are as small as, or even a bit smaller, than the average reported in the former habitat. It is often the most common species of giant flying squirrel in the Sundaic region.

Reproduction

Densities vary greatly in the red giant flying squirrel. In Taiwan ''grandis''), it varies from an average of around five animals per 20 ha in hardwood forests to around one-fifth that density in conifer plantations, although there are also reports of home ranges in the latter habitat that are as small as, or even a bit smaller, than the average reported in the former habitat. It is often the most common species of giant flying squirrel in the Sundaic region.

It has an oft-uttered call that especially is given at dusk, and in Himalaya ''albiventer'') has been described as a "monotonous repeated wail" or a "loud, penetrating and drawn-out whine". Sometimes small groups may actively call out to each other over a longer period. Otherwise the species typically occurs alone, or in pairs. The mother or pair are sometimes accompanied by a young, as they forage together for a few to several months after birth.

There is usually only one, infrequently two, young in a litter, as typical of giant flying squirrels. In Taiwan ''grandis''), there are two breeding seasons per year, with most births in January–February and July–August. In Uttarakhand of India, a young was found in a nest in May and in Malaysia pregnant females have been recorded in February. The young suckle for an extended period of time after being born; more than two months in ''P.'' ''albiventer''.

Food

The red giant flying squirrel is a herbivore, primarily a folivore, and has been recorded feeding on the leaves of many plant species. Young leaves are preferred over older leaves. Other items recorded in its diet are shoots, flowers, fruits, nuts, seeds, lichen, moss, twigs, bark and in the northern part of its range pine cones.

In Taiwan alone, ''P.'' ''grandis'' has been recorded feeding on at least 30 species of plants from 19 families. When feeding extensively on bark it may kill trees in the process and for this reason it is sometimes considered a pest in conifer plantations, while its frugivory can result in conflicts with humans in fruit plantations. Although not fully confirmed, there are strong indications that flower-feeding red giant flying squirrels may function as pollinators of certain trees. Some populations, at least ''P.'' ''yunanensis'', will visit specific locations to feed on minerals directly from cliffs/earth.

When only relatively poor food sources like older leaves are available, the red giant flying squirrel is still active, but less so compared to periods where richer food sources like young leaves and fruits are available.

While some species of giant flying squirrels will supplement their diet with small animals, primarily insects, this has not been reported in the red giant flying squirrel.