Distribution of Nycticebus pygmaeus and possibly existing other pygmy loris forms

N. pygmaeus
N. intermedius (proposed species)
Form of Bolikhamxay Province, Laos (proposed species, possibly corresponding to N. intermedius)

^{Taxonomy: forms distinguished from N. pygmaeus by some author are here included under the names / synonyms used in literature. The question of correct taxonomy is not supposed to be answered here.}

^{Faunal barriers within the distribution area of pygmy lorises in Vietnam, according to Fooden (1996):}

^{1) Mekong river: apparently restricts spreading of four of six non-macaque primate groups to the west.}

^{2) Distribution of primate species and subspecies indicates that a zoogeographic barrier formerly extended across Vietnam from east to west at about 14º-17ºN, possibly due to climatic changes during glaciation.}

^{Figures redrawn from photos by B. Meier and G. Anzenberger.} Type localities underlined

Lesser slow lorises:

Alterman, Freed 1997: researchers from China and Vietnam suggest that other slow loris species or subspecies exist. Also evidence for unidentified members of the genus in osteological collections (see Schwartz and Beutel 1995)
 

List of origin of described animals / specimens
 

General distribution:

based on the distribution map in Osman Hill, 1953, and on Groves, 1971, corrected with regard to other specimen localities and maps. In Vietnam widely distributed in forest areas, but common only in semi-evergreen and secondary forest, distribution from the north of Lang Son province, 21⁰ 30^I N 106⁰ 20^I E, to the south of Tay Ninh province, 11⁰ 43^I N 108⁰ 48^I E (Huynh 1998). In Laos in dense evergreen forest as the primary habitat. In China in west and south Yunnan (Ji, Peng 1990, Huynh 1998)
 
 

N. pygmaeus, possibly including other unidentified forms such as N. intermedius:
 
 

N. intermedius (proposed species):

Proposed as a distinct species, larger than N. pygmaeus, some hair and dentition differences described. Ratajszczak (1998): differences do not warrant even subspecific differentiation; Groves (1971) regarded intermedius as adults and pygmaeus as subadults of one species. Mitochondrial DNA: mean genetic distance to N. intermedius: 0,009 (0.006 - 0.012); mean genetic distance of both to N. coucang: 0.053 (0.046 - 0.067) (Zhang, Shen, Chi 1993). Distinguished from pygmaeus by cranial, dentition features and external features such as weight difference (450-800g; pygmaeus: 300-450 g, which, according to Ratajszczak 1998 may be due to rearing conditions of captive animals offered on local markets), presence of a dorsal stripe and little curly body hair (in pygmaeus: most hair curly) (Zhang et al., 1993). In Yunnan only in tropical rain and seasonal monsoon forests, which are humid with an annual average temperature about 16⁰C; highly seasonal breeder with estrous from middle of July to early September (Feng et al. 1993a, b). In Vietnam frequent only in semi-evergreen forest (Huynh 1998)
 

Form of Bolikhamxay Province, Laos (proposed species, possibly corresponding to N. intermedius):

New lesser slow loris in Bolikhamxay Province, Laos? Form discovered by Lon Alterman, Alterman and Freed 1997: ten captive, six wild individuals examined; initial suggestion: differ from others in pelage, body size and anterior dentition. Do not co-occur with N. pygmaeus, co-occur with N. coucang. May correspond to N. intermedius.
 

^{N. chinensis? Newspaper article of uncertain origin (of January / February 1998?) with a photo by SIPA Press.}
 

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