, Volume 35, Issue 1, pp 95–98 | Cite as

Caged rhesus macaques voluntarily work for ordinary food

  • Viktor Reinhardt
Short Communication


Eight single-caged adult rhesus macaques were given the choice of freely collecting their standard food ration, i.e. 33 biscuits, from an ordinary food box or working for its retrieval from a custom-made food puzzle. During a one-hour observation session following the simultaneous distribution of biscuits in both feeders, individuals spent on average a total of 32 sec retrieving 29.0 biscuits from the food box, and 673 sec retrieving 11.3 biscuits from the food puzzle. It was inferred that the animals voluntarily worked for ordinary food, with the expression of foraging activities serving as its own reward.

Key Words

Macaques Foraging Environmental enrichment 


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  1. Anderson, J. R. &A. S. Chamove, 1984. Allowing captive primates to forage. In:Standards in Laboratory Animal Science, Symposium Proceedings, Vol. 2, Universities Federation for Animal Welfare, Potters Bar, pp. 253–256.Google Scholar
  2. Jensen, G. D., 1963. Preference for bar pressing over “freeloading” as a function of number of rewarded presses.J. Exper. Psychol., 65: 451–454.Google Scholar
  3. Menzel, E. W., 1991. Chimpanzees (Pan troglodytes): problem seeking versus the bird-in-hand, least-effort strategy.Primates, 32: 497–508.CrossRefGoogle Scholar
  4. Neuringer, A. J., 1969. Animals respond for food in the presence of free food.Science, 166: 399–401.PubMedGoogle Scholar
  5. Osborne, S. R., 1978. A note on the acquisition of responding for food in the presence of free food.Anim. Learn. Behav., 6: 368–369.Google Scholar
  6. Reinhardt, V., 1993. Enticing nonhuman primates to forage for their standard biscuit ration.Zoo Biol., 12: 307–312.CrossRefGoogle Scholar
  7. ———— &A. Reinhardt, 1992. Quantitatively tested environmental enrichment options for singly-caged nonhuman primates: a review.Humane Innov. Altern., 6: 374–384.Google Scholar
  8. U. S. Department of Agriculture, 1991. Animal welfare, standards, final rule.Fed. Reg., 56: 6426–6505.Google Scholar

Copyright information

© Japan Monkey Centre 1994

Authors and Affiliations

  • Viktor Reinhardt
    • 1
  1. 1.Wisconsin Regional Primate Research CenterMadisonU. S. A.

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