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

Abstract

The study had three purposes: (1) to obtain information about mother-infant interactions in a rarely studied nocturnal prosimian, the pygmy loris (Nycticebus pygmaeus); (2) to compare pygmy lorises with a closely related and better-studied nocturnal prosimian, the Bengal slow loris (Nycticebus bengalensis); and (3) to determine how the presence of a second offspring affected mother-infant interactions in pygmy lorises. Three Bengal slow loris mothers and 3 pygmy loris mothers served as subjects, along with their 10 offspring (4 Bengal slow loris singletons, 2 pygmy loris singletons and 2 sets of pygmy loris twins). Observations were carried out in a zoo research facility for the first 24 weeks of the infants’ lives. Although the two species differ in size and reproductive patterns, mother-infant interactions were similar. The primary modes of infant and adult contact were ventral and passive contact, respectively. Mothers parked their infants from the first week, and infants followed from the second week. Mothers displayed little protection or rejection, and there was little aggression. Infants solicited play and social grooming from their mothers. Pygmy loris mothers engaged in social grooming and play with their infants more frequently and for longer periods if the infant was a singleton rather than a twin.

Diets high in fruits and low in gum exudates promote the occurrence and development of dental disease in pygmy slow loris (Nycticebus pygmaeus)

“…Fruit has specifically been identified as a possible cariogenic agent [Moynihan, ]. Dental diseases linked with sugar intake in humans are caries, root caries (which leads to infections), gingivitis, and facial and mandible abscesses, all of which have been identified in captive slow lorises [Debyser, ; Fitch‐Snyder et al, ; Sheiham, ; Fuller et al, ].…”

“…Asian slow lorises are found in zoos and rescue centres worldwide with Nycticebus pygmaeus , the pygmy slow loris, boasting the largest population in captivity. These vulnerable primates [Streicher et al, ] are largely fed a diet high in fruit and concentrates [Fitch‐Snyder and Schulze, ]. Starr et al Nekaris [2013] report feeding observations to be 40% insects, 30% nectar and, 30% exudates and sap.…”

“…Individual N. pygmaeus are recommended to breed or not and to be moved to other institutions to ensure genetic diversity. Yet breeding is successful only for a few key collections and health ailments are common [Debyser, ; Fitch‐Snyder and Schulze, ; Fuller et al, ]. All studies state nutrition as a possible causative agent of low breeding success and important presence of illness, however no attempts at providing empirical evidence were attempted.…”

“…Fruits are known to be prevalent within the diets slow lorises, both in zoos and in rescue centres, with gum exudates being used more as enrichment and not a dietary staple [Fitch‐Snyder and Schulze, ]. Health issues have been reported to be widespread, with dental issues being the most prominent.…”

Not all lorises are slow: rapid arboreal locomotion in Loris tardigradus of Southwestern Sri Lanka

“…Lorises and pottos have long been considered a relatively unspeciose and behaviorally uniform group, perhaps as a result of being the most understudied primate clade [Rasmussen, 1997]. As interest in this group grows, new species are being recognized and details are emerging regarding dietary differences [Nekaris & Jayewardene, 2003;Pimley, 2002] and behavioral variation in mating and rearing systems [Fitch-Snyder & Ehrlich, 2003;Nekaris, 2003a]. Our work shows that even the most fundamental link uniting the lorises and pottos-that of slow, cautious climbing-is also open to new discoveries of unexpected variability.…”