Journal Article


Slow lorises (Nycticebus spp.) really are slow: A study into food passage rates

Abstract

The characteristics of food ingested by a primate affect its assimilation of energy by modulating food passage rate. In general, digestive time increases in folivorous primates and decreases in frugivorous primates when they are fed higher fibre diets but this relationship is understudied in exudativorous primates. We compared the food passage rate of five slow loris species. We studied 34 wild-caught slow lorises (15 Nycticebus coucang, 15 N. javanicus, and four N. menegensis) in an Indonesian rescue centre and four captive-born slow lorises (two N. bengalensis and two N. pygmaeus) in a UK institution. We fed the Indonesian animals two different diets: a captive-type diet comprising fruits, vegetables and insects, and a wild-type diet formulated to be similar in nutrients to that consumed by slow lorises in the wild, consisting of gum, insects, vegetables and nectar. We fed the UK animals a diet of gum, vegetables, insects and hard-boiled eggs. We formulated this diet to mimic the wild diet, with notably higher fibre fractions and lower soluble sugars than the previous diet. We measured two variables: the transit time (TT) and the mean retention time (MRT). We mixed 1 tsp of glitter in bananas or gum as our markers and fed them to the slow lorises immediately prior to their main diet. We noted the date and time of feeding and of appearances of the marker in faeces. We weighed food given and left over for each animal to calculate ingested foods and nutrients. We found that TTs were not affected by diet treatment but MRTs were significantly longer for all species fed the wild type diet. Our results show that Nycticebus spp. have long MRTs for their body weight, and N. pygmaeus may have the slowest MRT of all primates in relation to body mass. The digestive flexibility of exudativorous primates should allow them to maximise fermentation opportunities when they ingest more (appropriate) fibre by increasing the amount of time the fibre substrate stays in the large intestine. Exudativorous primates appear to have plastic digestive strategies that may be an adaptation to cope with relatively nutrient-poor staple food sources such as gum. The provision of gum in a captive setting may therefore provide benefits for gut health in slow lorises.

Attached files

Authors

Cabana, Francis
Dierenfeld, Ellen
Wirdateti, Wirdadeti
Donati, Giuseppe
Nekaris, KAI

Oxford Brookes departments

Faculty of Humanities and Social Sciences\Department of Social Sciences

Dates

Year of publication: 2017
Date of RADAR deposit: 2017-07-11


Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License


Related resources

This RADAR resource is the Accepted Manuscript of Slow lorises (Nycticebus spp.) really are slow: A study into food passage rates

Details

  • Owner: Rosa Teira Paz
  • Collection: Outputs
  • Version: 1 (show all)
  • Status: Live
  • Views (since Sept 2022): 302