Pygmy Slow Loris

The pygmy slow loris has a head and body length (measured from the top of the head to the base of the tail) of 195–230 mm (7.7–9.1 in); there is no significant difference in size between the sexes. The length of the skull is less than 55 mm (2.2 in). The tail is short, averaging 1.8 cm (0.71 in) in length. The bodyweight ranges between 360 and 580 g (13 and 20 oz), with an average mass of 420 g (15 oz) for males and 428 g (15.1 oz) for females. There are, however, large seasonal variations in bodyweight, and individuals up to 700 g (25 oz) have been recorded. The animal tends to have significantly higher bodyweights during the winter months, about 50 percent higher than the lowest values in the summer. The weight gains, achieved largely by increasing food intake, are triggered by changes in the length of the day and night. This seasonal change in bodyweight occurs in both sexes, in both pregnant and non-pregnant females—an adaptation thought to help ensure survival during winter when food resources become scarce. The species has distinctive teeth morphology: its third molar is triangular in outline and only slightly smaller than the first molar; its second molar is the largest. …

The pygmy slow loris is distributed east of the Mekong River in Vietnam, eastern Cambodia, Laos, and Yunnan province in southern China. In Laos, populations have been recorded in Phou Khaokhoay, Nam Kading, Nam Theun, Nakai–Nam Theun, Khammouane Limestone, Dakchung Plateau, and Bolaven Northeast. In Vietnam, the pygmy slow loris was widespread throughout the country, but concern is increasing with conservation and rehabilitation efforts in Cat Tien National Park. Its encounter rate, determined from two field studies from Laos and Vietnam combined, was 0.05–0.08 lorises/km. In Cambodia, this value ranged from 0 in Mondulkiri Protected Forest to 0.10 in Phnom Prich Wildlife Sanctuary. In China, it has been recorded only in Pingbian, Hekou, Jinping, and Lüchun counties of Yunnan. It inhabits semi-evergreen, secondary, and Temperate broadleaf and mixed forests.

The pygmy slow loris is nocturnal, although it is least active on cold, moonlit nights and is generally active on dark nights, regardless of temperature. In the wild, it is normally encountered alone, or in small groups of two to four individuals. Males use scent marking to defend territories and mark their boundaries. Females prefer to mate with males whose scent is familiar. Males will also countermark—mark over or adjacent to another individual's mark deposited earlier—to advertise competitive ability to females. Females actively prefer countermarking males to males whose odors have been countermarked. The pygmy slow loris produces an apocrine secretion on scent glands near their elbow (brachial glands). This clear liquid, when mixed with its saliva, creates a volatile, noxious toxin. When startled, the slow loris licks its brachial glands and applies the secretion to its head. The oily secretion contains a complex mixture of volatile and semi-volatile components; one chemical analysis indicated over 200 components were present. One of the components is a member of the secretoglobin family of proteins, and similar to an allergenic protein found in cat dander. …