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By Jae H. Kim
Geographic Range
Loris tardigradus occurs in India and Sri Lanka (MacDonald, 1984).
Habitat
Slender lorises are able to live in various habitats, including wet and dry zones, lowland and highland forests (Hill, 1953).
These animals are found in the following types of habitat:
tropical 
; terrestrial .
Terrestrial Biomes:
forest ; rainforest .
Physical Description
(2.99 to 12.25 oz)
(6.89 to 10.39 in)
Loris tardigradus ranges in weight from 85 to 348 g. These diminutive primates measure 175 to 264 mm, and lack an external tail.
Slender lorises usually have a gray or reddish coat. However, this varies according to subspecies. The most distinguishing characteristics are the very long, slender arms and legs. They also have large eyes and ears.
(Nowak, 1999; Grzimek, 1990).
Some key physical features:
endothermic ; homoiothermic; bilateral symmetry .
Reproduction
These animals are capable of producing young two times per year.
Slender lorises mate in April to May and October to November.
Data are lacking on the mating system of these animals. However, they are usually found living alone or with a single mate. This would indicate that the species is monogamous. It is possible that limited polygyny is practiced, as well, if the home range of a male overlaps those of multiple females.
Mating systems:
monogamous ; polygynous .
Slender lorises mate in April to May and October to November. Females reach sexual maturity at about 10 months of age. Females apparently enter estrus twice per year, and are receptive for about one week. Female slender lorises usually have one young, occasionally two, per birth. The estrus cycle is usually 29 to 40 days and gestation is usually 166 to 169 days. Females nurse their young for 6 to 7 months (Nowak, 1991).
Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous .
Data are lacking on the parental behaviors of this species. Females give birth to one or two offspring. They care for their young for at least 6 to 7 months. The role of males in parental care has not been described.
Parental investment:
altricial ; pre-fertilization (provisioning, protecting: female); pre-hatching/birth (provisioning: female, protecting: female); pre-weaning/fledging (provisioning: female, protecting: female); pre-independence (protecting: female); extended period of juvenile learning.
Lifespan/Longevity
[External Source: Max Planck Institute for Demographic Research]
On individual is reported to have lived 15.5 years on captivity.
Behavior
Slender lorises are nocturnal and spend the day in a hollow tree or curled up in a vertical posture with their rumps in the angles of branches. They maintain this posture by grasping neighboring twigs. They have owl like appearance because of their habit of swaying from side to side when disturbed (Hill, 1953).
Slender lorises usually live alone or with a mate. Studies have shown that they are very aggressive. When several individuals were kept together, there was initially constant squealing and then fighting, sometimes resulting in death (Nowak, 1991).
Communication and Perception
Communication in slender lorises has not been well documented. Vocalizations have been reported, which appear to have a communicative function. In addition, if these animals are like other prosimians, they likely use some froms of scent-based communication, helping them to attract mates and mark their territories. Tactile communication occurs between a mother and her offspring, as well as between mates and rivals. The role of visual signals, such as body postures and facial expressions is not known. (Nowak, 1991)
Food Habits
Slender lorises are chiefly insectivorous but also include shoots, young leaves, fruits with hard rinds, bird's eggs, and small vertebrates in their diet (Nowak, 1991). They consume all parts of their prey. They were observed to eat feathers, scales, and bones of the vertebrates; and horny exoskeletons of insects (Pocock, 1939).
Primary Diet:
carnivore (insectivore ).
Animal Foods:
eggs; insects.
Plant Foods:
leaves; fruit.
Predation
Details on predation of these lorises are not available. It is likley that they fall victim to nocturnal predators, such as owls, snakes, and small carnivorous mammals.
Ecosystem Roles
Loris tardigradus may play an important role in local food webs. This species consumes insects, possibly structuring insect populations and having some impact upon the insect community. In addition, these lorises may serve as prey to larger animals.
Economic Importance for Humans: Negative
There are no known adverse effects of slender lorises on humans.
Economic Importance for Humans: Positive
Loris tardigradus has no documented positive effect on human economies.
Conservation Status
IUCN Red List: [link]:
Endangered.
US Federal List: [link]:
No special status.
CITES: [link]:
Appendix II.
These lorises are endangered, and appear to be losing habitat.
Other Comments
Research on the thermoregulation of slender lorises reveals that they are able to tolerate high environmental temperatures, largely due to their ability to considerably increase evaporative cooling (Muller, Nieschalk, and Meier, 1985).
Contributors
Jae H. Kim (author), University of Michigan.
Nancy Shefferly (editor), Animal Diversity Web Staff.
