Behaviour and Reproduction Of the Slender Loris (Loris tardigradus) in Captivity

Abstract

Observations were made on the behaviour of a group of slender lorises (Loris tαrdigrαdus) maintained in the Adelaide Zoo. Descriptions of their individual behaviour, social interactions, reproductive biology and development of young are given. The slender loris displays a more complex social lifestyle than has previously been reported, with huddling, marking activities and the behavioural complex of stretching/wrestling/allogrooming occurring daily. Evidence of the formation of a female coalition is described for the first time for this species. The low reproductive success of the group may have been attributable to the mixing of two Sri Lanka subspecies. Matings between L. tαrdigrαdus grαndis and L. tαrdigrαdus tαrdigrαdus produced one sibling that reached maturity but did not breed.

Mother-Infant Interactions in Slow Lorises (Nycticebus bengalensis) and Pygmy Lorises (Nycticebus pygmaeus)

“…The slender loris, in Asia, differs from all other lorisines in that infants are relatively altricial at birth and are not parked until they are at least 2 weeks old [Nekaris, 2003]. In captivity, infants are carried for at least 1 month [Goonan, 1993;Rasmussen, 1986] and possibly longer [Schulze and Meier, 1995]. It is assumed that the typical dispersal pattern among lorisines is for females to remain near the mother while males move some distance away [CharlesDominique, 1977].…”

“…As has been done in other studies of captive prosimians, the animals were maintained in naturalistic enclosures that contained branches, walkways, shelves and nestboxes [Ehrlich and MacBride, 1989;Goonan, 1993]. Slow lorises were housed in cages that measured 3 × 1.8 × 2.4 m. Pygmy lorises were kept in smaller cages (1 × 1 × 2 m) because infants of this species sometimes fell when housed in larger cages [Karen Weisenseel, pers.…”

Observations of Mating, Birthing and Parental Behaviour in Three Subspecies of Slender Loris (Loris tardigradus and Loris lydekkerianus ) in India and Sri Lanka

“…It is the smallest of the lorises, weighing only 85-162 g [Osman Hill, 1953;Nekaris and Jayewardene, 2003]. Some information is available from captive groups regarding its behaviour, along with some preliminary field observations [Still, 1905;Phillips, 1931;Goonan, 1993;Nekaris and Jayewardene, 2003]. …”

“…Anatomical research relating to reproduction has focused on various changes in the internal anatomy of the male reproductive system, spermatogenic cycles, changes in seasonal testicular volume and the biochemistry of the female reproductive tract Prasad, 1962, 1967;Ramaswami and Anand Kumar, 1965;Manjula and Kadam, 1980;Swayamprabha, 1983;Manjula, 1984;Manjula and Kadam, 1984;Sarma and Kadam, 1984]. A second line of inquiry has attempted to resolve issues of evidence of birth seasonality, gestation length, litter size and other life history variables for both Indian [Ramaswami and Anand Kumar, 1962;Manley, 1966Manley, , 1967Kadam and Swayamprabha, 1980;Izard and Rasmussen, 1985;Rasmussen and Izard, 1988] and Sri Lankan slender lorises [Osman Hill, 1935;Nicholls, 1939;Nieschalk and Meier, 1984;Goonan, 1993;Schulze et al, 1994]. These studies have come to contradictory conclusions with regard to whether the presence or absence of seasonality is an artefact of captivity and also to whether or not differences in gestation length, time of weaning and litter size are due to phylogenetic or environmental effects.…”

Social Behaviour of the Slender Loris (Loris tardigradus lydekkerianus)

“…Although based on small sample sizes, six subspecies (four in Sri Lanka and two in southern India) are recognised on the basis of differences in pelage, body weight and geographic locations [8,9]. Studies on social behaviour of individuals housed in captivity report affiliative behaviour between adults [10,11] as well as mutual intolerance and constant fighting [10,12]. Schulze and Meier [13] note that the degree of aggressiveness declined in their colony of animals over time and hypothesise that the more ready availability of food might be a reason for this.…”