d) According to Mewa Singh (pers. comm.), lorises imported from Sri Lanka are not necessarily representatives of Sri Lankan forms because smuggling of lorises between India and Sri Lanka may occur.
of the limited reliability of distinguishing features, the
key below does not yet allow a clear identification; consideration of
many features as possible including geographic origin, if known, remain
necessary. A verification of taxonomy, considering ecological
and reproductive separation, and discovery of reliable phenotypic
allowing to identify live animals would be desirable for conservation.
Key to the presently known forms / subspecies within the genus Loris
Hair length up to 3 cm (extreme highland form), ears completely hidden
by fur, limbs thickly furred, superficially nycticebus-like;
colour: earthy-brown with no reddish tinge; origin: montane rain and
forests of the central highland of Sri Lanka (Horton Plains):
L. t. nycticeboides Osman Hill, 1942.
(Existence of similar, thickly furred forms in higher regions of India?)
shorter, ears clearly visible: 2
Relatively small animals (head-body-length up to 22 cm, weight about 85
- 135 g, foot length 35-45 cm), fur soft, velvety with little true
brown, reddish or brownish-grey: rainforest forms, L. t. tardigradus
or L. t. malabaricus; see figure 1 3
small animal; fur yellowish or reddish-yellowish, reddish circumocular
patches. Ears in infants from Polonnaruwa yellowish with a
pigmented rim, in other regions pigmantation possibly more variable;
below, under 5:
Possibly juvenile L. t. nordicus. (See under 5: large grey dry zone forms).
(Juveniles of L. t. lydekkerianus similar? One juvenile / subadult L. t. lydekkerianus was described as greyish-buff with chestnut circumocular patches (Osman Hill 1933).
Recorded head-body-length 19.8-25.6 cm, foot length 38-47 mm. Distal parts of limbs well covered with fur. Dorsally dark grey, blackish or brownish-grey, in males sometimes slightly rusty on lumbar region . Throat hair pure white throughout, ventral colour pure white or only slightly buff with dark hair bases, white zone surrounding the dark circumocular patches, preauricular hair between this zone and the ears clearly darker. (In some L. t. nordicus from Polonnaruwa the circumocular patches are also surrounded by whitish hair, but then preauricular hair closer to the ears is whitish or very light grey with no marked contrast to that around the circumocular patches). Fur according to Osman Hill more coarse with a higher amount of true hair than in the more soft, velvety fur of the other forms which mainly consists of woolly hair. Photos show animals with a peculiar facial appearance (heart-shaped face with the appearance of a long muzzle): see figure 2. (A facial appearance as in L. t. grandis is also found in some small reddish specimens imported from Sri Lanka; see figure 1 f - h; see below, under 6 a, possible intermediate form).
(Features above mainly based on Osman Hill´s data. According to Goonan et al., 1995 and Groves 1998 examined skins were said to be indistinguishable from L. t. nordicus skins)
t. grandis Hill and Phillips, 1932, Highland slender loris.
head-body-length 20.5-26 cm, foot length 45-56 mm, weight usually more
than 220 g in adults; fur soft, grey, yellowish-grey, grey-brown, buff
or dirty deep fawn (in subadults occasionally with a slightly reddish
large grey dry zone subspecies, L. t. nordicus or L. t. lydekkerianus; see under 5, 6b.
Small rainforest slender lorises:
Origin: India; head-body-legth 18 - 22 cm (weight data insufficient,
g mentioned), foot length 44-45 mm, throat hair buff throughout (hair
coloured like tips), ventral colour buff or dirty white:
L. t. malabaricus Wroughton, 1917, Malabar slender loris.
(Throat hair colour: difference to L. t. tardigradus? But see under 7 a). The distribution area of this form includes lowland and highland regions; density and length of fur might differ.
Origin: Sri Lanka; head-body-length 18.2-20.6 mm, reported weight about
85 - 142 g, foot length 35-44 mm; throat hair buff with dark grey hair
bases (throat hair colour: difference to L. t. malabaricus?
captive small reddish or brown animals belonging to stock from Sri
show an entirely white throat, see under 6a). Ventral colour buff or
preauricular hair grey, never white, velvety fur with a minimum of true
hair, distal parts of limbs sparsely haired or hairless:
L. t. tardigradus Linnaeus, 1758, Slender loris (see figure 1 a - h).
5) Large grey dry zone forms:
Sri Lanka. Head-body-length in wildcaught animals 20.5 - 23.8 cm, in
captive-bred animals up to 26 cm. Weight, 198 - 360 g; in wildcaught
from Polonnaruwa 228 - 287 g (566-679.2 g for Wilachchiya animals
erroneous) ; foot length 42-55 mm. Ear pigmentation possibly variable,
yellow ears; in a population of L. t. nordicus from Polonnaruwa
with unpigmented yellow ears, juveniles with pigmented brown ear rims;
according to Osman Hill black ears (erroneous?). Bases of ventral hair
usually with a grey base (in some specimens from Polonnaruwa, hair at
in the median part of ventral side white throughout or with very light
grey, almost white bases), lowland form with thin fur on dostal parts
limbs. In captivity non-seasonal breeder.:
L. t. nordicus Hill, 1933, Northern Ceylonese slender loris
(but see below, 6 b: no difference between L. t. nordicus and L. t. grandis?).
India. Head-body-length 22.3 - 26.3 cm,weight 226.8 - 346.6 g, foot
45 - 57.5 mm. Ears dark or with a dark rim (at least no information
populations with unpigmented ears has been found); bases of ventral
usually without, seldom with a tiny grey base. Distribution area
lowland and highland regions, local differences in length and density
fur seem possible. Evidence for seasonal breeding both in captivity and
in the wild: L. t. lydekkerianus Cabrera, 1908, Mysore
Photos: Anna Nekaris
6) Possibly existing intermediate forms and possible local variations:
6 a) Intermediate forms between L. t. grandis and the lowland forms of Sri Lanka are reported from the wild, intermediate tardigradus / grandis forms for instance occurring in the hills near Kandy (Phillips, 1935). Wildcaught specimens of unknown origin, imported from Sri Lanka, resembled L. t. tardigradus with regard to small size and the lack of a white zone around the circumocular patches, but showed an entirely white throat and the facial appearance as in L. t. grandis (with a "long muzzle", see figure 1 f - h).
b) Difference between L. t. grandis and and the adjacent
form L. t. nordicus: Osman Hill describes differences whereas,
to Goonan et al., 1995, no differences between preserved skins and
of L. t. grandis and L. t. nordicus in the Natural
Museum, London, were found. A white throat and white zone around the
circumocular patches are not only found in L. t. grandis, but
in some L. t. nordicus from Polonnaruwa; in the latter,
preauricular hair behind such a white rim is not clearly darker, but
whitish or very light grey. In two live grey Sri Lankan lorises kept in
Adelaide (exact origin of both unknown), phenotypic and karyological
were found (Goonan et al., 1995). The conclusion in Goonan et al. from
these findings was that L. t. nordicus and L. t. grandis
probably belong to one subspecies of grey lorises, but that some local
differences may still be present. If both forms were identical, L.
nordicus would be a synonym for the older name L. t. grandis.
Lorises and pottos: species, subspecies, local populations
Preliminary draft; H. Schulze, B. Meier, H. Fitch-Snyder
Last amendment: 23. July 2001