Ratufa macroura (Pennant, 1769)
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publication ID |
https://doi.org/ 10.5281/zenodo.6840226 |
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DOI |
https://doi.org/10.5281/zenodo.6840224 |
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persistent identifier |
https://treatment.plazi.org/id/064D0660-FFC9-ED35-FA17-FCF9FA94F493 |
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Diego |
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scientific name |
Ratufa macroura |
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Sri Lankan Giant Squirrel
French: Ecureuil du Sri Lanka / German: Sri-Lanka-Riesenhérnchen / Spanish: Ardilla gigante de Sri Lanka
Other common names: Grizzled Giant Squirrel
Taxonomy. Sciurus macrourus Pennant, 1769 .
“Ceylon and Malabar...Malacca... Goa and Amboina.” Restricted by W. W. A. Phillips in 1933 to highlands of Central and Uva Provinces, Sri Lanka.
Three subspecies are recognized.
Subspecies and Distribution.
R.m.macrouraPennant,1769—CSriLankahighlands.
R.m.dandolenaThomas&Wroughton,1915—SIndia(EasternandWesternGhats)andN&ESriLanka(DryZonelowlands).
R. m. melanochra Thomas & Wroughton, 1915 — SW Sri Lanka (Wet Zone lowlands).
Descriptive notes. Head—body 323-396 mm,tail 350-362 mm; weight c.1-6 kg. The Sri Lankan Giant Squirrel, a large tree squirrel, has a tail that is long, broad, and haired; ear tufts, if present, are nearly inconspicuous, ¢.5 mm in length. It has a creamy gray to brownish gray dorsum. Small blackish cheek patches are surrounded by buff cheek patches. Forearms, wrists, and legs are a light whitish to creamy buff; toes are dark gray to brown. Subspecies macroura is distinguished byits black tail with white hair tips, and by a gray band separating black dorsum from yellowish venter. Subspecies maxima is similarly colored but has black over shoulders, rump, and tail. Subspecies dandolena has a black crown; shoulders and dorsal midline are variably black, but lower back is brown. It has long pale hairs on the tail, making tail appear grayer than in the other subspecies. Subspecies melanochra has a black dorsum and tail, butit lacks white hair tips and gray line separating dorsum from yellowish venter. Hybridization between dandolena and the Indian Giant Squirrel subspecies (R. indica maxima) was reported in the south-eastern Indian state of Tamil Nadu but does not appear widespread.
Habitat. Evergreen broadleaf forests of southern India and Sri Lanka. On eastern side of the Western Ghats in Karnataka, Kerala, and Tamil Nadu, the Sri Lankan Giant Squirrel lives in riparian forests dominated by 7Terminalia (Combretaceae), Tamarindus, Pongamia, and Albizia (all three family Fabaceae), Mangifera (Anacardiaceae), and Syzygium (Myrtaceae), and is often found in scrub and dry deciduous forests below c.500 m, especially when sympatric with the Indian Giant Squirrel. In Sri Lanka,it has been reported from a variety of dry and humid forests but seems most common in lowlying forests, especially associated with tamarind (Tamarindus indica).
Food and Feeding. The Sri Lankan Giant Squirrel feeds on seeds and occasionally ingests fruit pulp, bark, sap, nectar, pollen, flowers, and leaves, especially the young leaves of Tamarindus, and Albizia. About 45% of the diet of both males and femalesis seeds of young fruit; leaves are also favored and compose 25-30% of diet. Termites are regularly consumed. It does not cache food. Foraging is almost exclusively arboreal as this species rarely descends to the ground.
Breeding. Breeding in the Sri Lankan Giant Squirrel follows a mating chase between the male and estrous female culminating in a copulation lasting a few seconds. Female is receptive only for a single day each year in October or November. Gestation lasts 26-28 days with peak season of birth in early December. Litter size is often just one young. Young remain in the nest for 2-6 months before emerging in late February. Weaning is complete by 4-6 months of age with dispersal occurring May-July. Ratio of adult female to young in the population is 1:0-3 or 0-32.
Activity patterns. The Sri Lankan Giant Squirrel is diurnal and lives most often above 20 m in the canopy, where it constructs a spherical drey of twigs and leaves 30-40 cm in diameter. Dreys are constructed and anchored with climbing vines and lianas in midto-upper branches of canopy. These squirrels usually exit their nests in the morning at ¢.06:00 h and can be active throughout the day but are most active between dawn and 10:00 h, with a second peak of activity that begins after 14:30 h. Rain and high temperatures reduce activity outside of the nest. Feeding accounted from ¢.38% of daily activity with 26% of the day spent resting on tree branches. Individuals move to lower canopy when threatened by their most significant natural predator, the Indian black eagle (Ictinaetus malayensis), and upward when human poachers are present.
Movements, Home range and Social organization. Population density of the Sri Lankan Giant Squirrel is low (less than 5 ind/100 ha) with slightly more females found in a population than males. Locomotory behavior accounts for ¢.8% of day. The Sri Lankan Giant Squirrel is solitary and territorial, covering areas of 0-82-10 ha with no discernible difference between sexes. Although there is intraspecific territorial defense through aggressive chases and deposition of scent marks, males and females may
overlap 22% in undisturbed areas and 58% in disturbed forests. Movement is greatest in dispersal and post-dispersal seasons (May—October) than during the seasons with young in and near the nest (November—April); over the course of a year mean distance of travel was 860-3 m/day for males and 694-3 m/day for females. The Sri Lankan Giant Squirrel lives in the middle and upper canopy, seldom below 20 m.
Status and Conservation. CITES Appendix II. Classified as Near Threatened on The IUCN Red List. The severely fragmented Indian population of the Sri Lankan Giant Squirrel has been estimated to be less than 500 mature individuals and has been declining at a rate greater than 30% in the last 25 years due to habitat loss and hunting for local consumption. Presence of domestic predators and hybridization with the Indian Giant Squirrel are also considered major threats. Nevertheless, current distribution is not clearly known, and new records have been published over the years. Sri Lankan population is considerably larger and appears to be less threatened.
Bibliography. Babu & Kalaimani (2014), Baskaran et al. (2011), Eisenberg & Lockhart (1972), Johnsingh & Manjrekar (2015), Jordan et al. (2005k), Joshua & Johnsingh (1994), Joshua et al. (2008), Karthikeyan et al. (1992), Moore & Tate (1965), Phillips (1933), Ramachandran (1989), Rao et al. (2015), Thorington et al. (2012).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
