Medicinal plant exudativory by the Bengal slow loris Nycticebus bengalensis

Abstract

Slow lorises are members of a rare guild of obligate exudativores. Secondary metabolites in their diet have been implicated as contributing to the evolution of both their slow basal metabolism and their venom. No long-term study has yet examined the feeding ecology of the largest of the lorises, the Bengal slow loris Nycticebus bengalensis. We conducted an 18 mo study from June 2008 to December 2010 in Hollongapar Gibbon Wildlife Sanctuary, Assam, India, to investigate whether Bengal slow lorises prefer gum, and whether there is any evidence of secondary metabolites in their diet. We detected the lorises along line transects using existing trails and followed each animal as long as possible, recording selected behaviours via focal instantaneous sampling. We recorded 629 feeding incidents during 270 night walks. We found that up to 80.9% of feeding bouts were of plant exudates, followed by bark, floral parts, insects, fruits, and tender (i.e. immature) leaves. Within the plant exudate category, 5 species were consumed in 71% of the total exudate feeding bouts: Terminalia chebula, Mesua ferrea, T. arjuna, Ficus hispida and Dillenia indica. These species all have high medicinal value and are commonly used by the local communities for traditional medicinal purposes. Absorption of secondary metabolites from these plants may explain unusual healing patterns observed in wild slow lorises, but lacking in lorises held in captivity. Their dietary affinity towards medicinal plants could explain patterns of use of slow lorises within the traditional medicine trade in the Indo-Chinese region. 23: 149-157, 2014 to-digest secondary metabolites (Heymann & Smith 1999). Only 6 primate genera (Calithrix, Mico, Ce buella, Phaner, Euoticus and Nycticebus) are known to access these foods through active excavation of plant surfaces (Starr & Nekaris 2013). These obligate exudativores include exudates in ≥40% of their feeding time (hereafter referred to as diet; Nash & Burrows 2010). KEY WORDS: Lorisidae · Exudativory · Feeding ecology · Secondary metabolite · India Resale or republication not permitted without written consent of the publisher Contribution to the Theme Section 'Conservation and ecology of slow lorises' FREE REE ACCESS CCESSEndang Species ResUntil the mid-1990s, virtually nothing was known about the feeding ecology of wild slow lorises (Nycticebus spp.), and the discovery that these small primates consumed large quantities (comprising nearly 40 to 90% of the diet) of exudates was surprising; indeed it had been predicted that like the similarly non-leaping pottos of Africa, loris diet would comprise mainly fruits (Ravosa 1998). Several morphological characters of these nocturnal strepsirrhines suggest the presence of obligate exudativory, including a stout toothcomb, small body size, a large caecum, a long tongue, wide U-shaped legs and enlarged hand pads for gripping (Hladik 1978. Wiens et al. (2006), Swapna et al. (2009) and Starr & Nekaris (2013) all provided strong evidence that exudates are a preferred ...

Mangifera sylvatica (Wild Mango): A new cocoa butter alternative

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The seasonal feeding ecology of the javan slow loris (nycticebus javanicus)

“…All other studied slow loris species (studied in secondary or primary forests) also reported an exudate and insect based natural diet (Starr & Nekaris, 2013;Das et al, 2014;Wiens et al, 2006). All other studied slow loris species (studied in secondary or primary forests) also reported an exudate and insect based natural diet (Starr & Nekaris, 2013;Das et al, 2014;Wiens et al, 2006).…”

“…Although originally suggested to be frugivorous based on comparisons with pottos (Charles-Dominique, 1977), wild field studies have clearly demonstrated that slow lorises (Nycticebus) are specialized exudativores (gum specialists) (Nekaris, 2014). The largest of the lorisines (1.1-2.4 kg), the Bengal slow loris (N. bengalensis) has been observed spending the majority of its feeding time on exudates (Pliosungnoen et al, 2010;Swapna et al, 2010), with only 4.45% time spent eating fruit (Das, Nekaris, & Bhattacharjee, 2014). The smaller bodied pygmy slow loris (N. pygmaeus) (350-550 g) has rarely been observed to ingest fruit in the wild, focusing on a diet of gum, nectar and insects (Starr & Nekaris, 2013;Streicher, 2009).…”

Trialling exudate-based enrichment efforts to improve the welfare of rescued slow lorises Nycticebus spp.

“…Conducted crudely with wire cutters, nail clippers, or pliers, this procedure causes the death of many animals due to infection (Streicher et al 2008). Considering that the toothcomb is vital for defence, grooming, socialising with other lorises and, perhaps most importantly, gouging for gum (the most important element of a slow loris's diet) (Wiens et al 2006, Swapna et al 2010, Starr & Nekaris 2013, Streicher et al 2013, Das et al 2014, those that survive cannot be returned to the wild (Nekaris et al 2013b). …”