Ratufa indicaIndian giant squirrel

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Geographic Range

The distribution of Ratufa indica is restricted to peninsular India. With increasing deforestation in the region, the geographic range of R. indica continues to decrease (Nowak 1999).

Habitat

Ratufa indica is arboreal, spending most of its time in trees. It makes its shelter within holes in trees. Moving from tree to tree, R. indica can leap 6 meters or more. Giant squirrels rarely leave the trees, usually only to chase other squirrels during the breeding season. Giant squirrels are found primarily in moist tropical forests (Nowak 1999).

Physical Description

Ratufa indica has dorsal coloration that varies from deep red to brown, the ventral fur is white. They have short, round ears, a broadened hand with an expanded inner paw for gripping, and large, powerful claws used for gripping tree bark and branches. Females can be distinguished from males by their three sets of mammae. Total body length varies from 254 to 457 mm and tail length is approximately the same as body length. These squirrels weigh approximately 1.5 to 2 kg (Nowak 1999).

  • Range mass
    3 (high) kg
    6.61 (high) lb
  • Average mass
    1.5 to 2 kg
    lb
  • Range length
    254 to 457 mm
    10.00 to 17.99 in

Reproduction

Little is known of mating behavior in R. indica. Males actively compete for females during the breeding season and pairs may remain associated for longer periods of time (Nowak, 1999).

Reproductive behavior of R. indica is poorly known. There is some evidence that breeding occurs throughout the year, or several times during the year. Litter size is usually 1 or 2 young, but may be as many as 3. Gestation period in a close relative, Ratufa bicolor, was recorded to be 28 to 35 days in length.

  • Range number of offspring
    1 to 3
  • Average number of offspring
    1
    AnAge
  • Range gestation period
    28 to 35 days

Ratufa indica build eagle-sized nests in the branches of trees and raise the young there until they begin to emerge from the nest and gain independence (Borges, 1992; Nowak, 1999).

Lifespan/Longevity

One captive R. indica lived to be 20 years old, longevity in the wild is unknown.

  • Range lifespan
    Status: captivity
    20 (high) years
  • Average lifespan
    Status: captivity
    20 years
    AnAge

Behavior

Giant squirrels are typically solitary animals, being seen only rarely in pairs during the breeding season. They are wary animals and usually keep well hidden in vegetation. They are most active during the day (Nowak, 1999). Giant squirrels have small home ranges (G. Umapathy, 2000).

Communication and Perception

Food Habits

Giant squirrels spend most of their time in trees, where they gather their food. Giant squirrels are omnivorous, feeding on fruits, flowers, nuts, bark, bird eggs, and insects. They feed by standing on the hind legs and using their hands to handle food. Giant squirrels also uses their large tail as a counter-weight, improving their balance (Nowak 1999).

  • Animal Foods
  • eggs
  • insects
  • Plant Foods
  • wood, bark, or stems
  • seeds, grains, and nuts
  • fruit
  • flowers

Predation

Giant squirrels escape predation primarily by seeking refuge in the trees and through their agility and wariness. It is likely that they are preyed upon by many medium and large-sized predators, such as cats, civet cats, raptors, and snakes.

Ecosystem Roles

Ratufa indica disperses the seeds of the plants that they consume as they defecate (Borges 1992).

  • Ecosystem Impact
  • disperses seeds

Economic Importance for Humans: Negative

Giant squirrels can do some damage to crops by eating seed, they can also compete with poultry by eating their feed (Katoch 1945).

  • Negative Impacts
  • crop pest

Conservation Status

Due to deforestation, the already limited habitat of R. indica is being reduced. Agencies such as the IUCN and CITES have acted to reduce their chance of extinction and any habitat further fragmentation (Nowak 1999).

Contributors

James Justice (author), University of Northern Iowa, Jim Demastes (editor), University of Northern Iowa.

Glossary

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

omnivore

an animal that mainly eats all kinds of things, including plants and animals

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

World Map

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

tactile

uses touch to communicate

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

References

Borges, R. 1992. A Nutritional Analysis of Foraging In the Malabar Giant Squirrel (*Ratufa indica*). Biological Journal of the Linnean Society, 47(1): 1-21.

G. Umapathy, A. 2000. The Occurence of Arboreal Mammals In the Rain Forest Fragments In the Anamalai Hills, South India. Biological Conservation, 92: 311-319.

Katoch, R. 1945. Isolation of Mycoplasma Species From Squirrels (*Ratufa indica*) From the Vicinity of Poultry Farms.

Nowak, R. 1999. Walker's Mammals of the World, 6th ed. Vol II. Baltimore, MD: The John Hopkins University Press.

Thorington, R., K. Darrow. 1996. Jaw Muscles of Old World Squirrels. Journal of Morphology, 230: 145-165.