Environmental Enrichment for Nonhuman Primates: Theory and Application

Abstract

Investigators have an obligation to promote the psychological well-being of nonhuman primates used in research. Considerable emphasis has been placed on providing nonhuman primates with enriched environments as a means to achieve this objective. A framework is provided that consists of a set of hypotheses about well-being, and the extent to which exposure to various enrichment devices and procedures actually promotes well-being is evaluated. Two hypotheses are concerned with fostering species-typical behavior: use (versus nonuse) of the enrichment, and whether use of enrichment helps normalize other aspects of the behavioral repertoire. Two additional hypotheses are concerned with abnormal behavior: whether currently existing enrichment lowers levels of abnormal behavior, and whether it prevents the behavior. This framework is applied to various enrichment strategies ranging from toys and foraging devices to social interaction. Most devices are used by nonhuman primates and thus constitute an important way to enrich the captive environment. However, enrichment devices vary as to their effectiveness in normalizing the behavioral repertoire and eliminating abnormal behavior. Only social contact satisfies the goal of promoting a wide variety of species-typical activities while at the same time reducing or preventing the development of abnormal behavior.

Locomotion and postural behaviour

“…A core concept in modern primate husbandry and management is environmental enrichment (e.g. Baker et al, 2006;Boere, 2001;Lutz and Novak, 2005;Reinhardt and Reinhardt, 2008;Wolfensohn and Honess, 2005). Its main aim is to enhance the psychological and social well-being of captive primates and to prevent behavioural disorders such as stereotyped behaviours, cognitive deficits, and emotional disturbances.…”

“…While toy use and play is often confined to the youngsters and novel toys often lose their attraction within a few days, foraging devices enrich the daily activity of captive primates regardless of age and sex. Challenging food acquisition has been shown to substantially promote species-typical behaviour and to significantly increase the time-budget for food seeking and feeding (Lutz and Novak, 2005).…”

Efecto del enriquecimiento ambiental en un grupo de monos araña (Ateles geoffroyi) en cautiverio

“…El enriquecimiento ambiental (EA) es un conjunto de acciones que propician un entorno estimulante para los individuos que viven cautivos con el objeto de que su comportamiento sea semejante a los individuos de la misma especie que viven en vida libre, con lo que se procura el bienestar de los animales. [11][12][13][14] En las últimas décadas, el EA ha tenido un auge importante para aplicarse entre los primates no humanos, 2,[15][16][17] ya que en los laboratorios es posible no sólo aminorar los efectos del confinamiento, 18,19 sino además mejorar los resultados obtenidos en estudios de conductas aberrantes y las alternativas para disminuir éstas son útiles para la ciencia médica. 1,3,20 Dado que en humanos con algún problema mental o en reclusión penitenciaria se presentan conductas similares a las de los primates no humanos en cautiverio, es pertinente implementar actividades que en este caso se conocen como de enriquecimiento ocupacional.…”

“…2,22,23 b. El enriquecimiento alimenticio incluye actividades que permiten que los monos prolonguen el tiempo y el esfuerzo que hacen para alimentarse, incluyendo el "forrajeo"; para ello se alternan los horarios y la forma en que los alimentos les son proporcionados. 2,13,[22][23][24] c. La introducción de objetos novedosos tiene la finalidad de compensar la carencia de objetos manipulables dentro de los encierros. Para ello se proporcionan juguetes y otros objetos que pueden manipular los individuos.…”

Changes in Food Intake and Abnormal Behavior Using a Puzzle Feeder in Newly Acquired Sub-Adult Rhesus Monkeys (Macaca mulatta): A Short Term Study

“…Investigators who use animals in biomedical and behavioral research have an obligation not only to conduct high-quality research, but also to promote the health and well-being of their animal subjects to the greatest extent possible given the research objective [9]. Most single-housed nonhuman primates in laboratory facilities, however, are not provided with environments that are sufficient to maintain their psychological well-being.…”