There are two types of behavior focused on feeding- appetitive and consummatory. Exploring, hunting, foraging, stalking and pouncing are appetitive behaviors; eating is consummatory. According to Viktor Reinhardt , many primates may spend more time foraging than any other activity. For example, marmosets will spend 50-60% of the day foraging, but when food is presented on a plate, the feeding (consummatory) activity lasts only a few minutes. Many substrates can be used to allow foraging; wood chips are just one example. The secret to keeping it interesting is to introduce novel items as forage, not just standard biscuits.
To be interesting, feeding should require some effort and skill. The act of gathering and processing is pleasurable on its own and animals will choose to work for feed rather than simply accept feed even if the same feed is available without effort. (Reinhardt and Roberts, 1997). Probe feeders allow the animal to probe with fingers or an object such as a stick in order to find food hidden from view in a chamber or compartment. Puzzle feeders require manipulative skills in addition to the collection of food. Animals will employ a number of strategies to remove the feed from the feeder.
The use of whole foods provides a focus on the preparation segment of normal feeding. This involves providing foods whole, with rinds, shells, husks and hulls that allow the animals to prepare food by removing the non-edible parts, another time consuming appetitive activity.
Care must be taken to assure that the novel feeders do not lose their novelty and revert to fancy food bowls. Rotation and randomness will keep the feeders fresh and interesting. Variety is also a consideration in the type of treats used for snacks and foraging grains.
And finally, when using foraging as enrichment, the food should not be present at all times, introducing randomness to feeding patterns. This requires the animals to be more attentive to items introduced into their environment.
In a research setting, the dietary requirements are controlled, but can become routine and boring to the animal. Retrieving food daily becomes a process of picking up biscuits and eating them. Animals whose feed is too easily obtained may be more prone to obesity. More importantly, the lack of challenge and occupation may lead to aberrant behaviors.
Check out some of the fun food and treats we carry for Primates.