The Influence of Novel Feeding Systems on the Behaviour of Captive Female Common Marmosets, 'Callithrix jacchus'

Abstract

The influence of novel feeding systems on the behaviour of eight female captive common marmosets, 'Callithrix jacchus', was determined through a series of experiments. Captive environments are often impoverished when compared to the richness of natural habitats and so can usually be found lacking in terms of choice, complexity, and change. Therefore, the welfare of animals kept in captive environments may be compromised. Environmental enrichment is used to improve welfare by emulating natural environments within captive environments so captive animals are provided with the surroundings and stimulation considered likely to promote species-typical behavioural repertoires. The University of New England marmosets have rotating free access, via a runway system, to another room that is four times larger than their home cages. This room is furnished similarly to the home cage with a proportionally larger number of furnishings, such as perches, platforms, nest boxes, tubes, tunnels, tyres, and hanging objects. The female marmoset subjects do voluntarily enter the room and utilize the different areas, but they choose to spend significantly more time in the home cages. Therefore, the added room space may not be as useable as the home cages. Since foraging enrichment is relatively inexpensive, easily implemented, and addresses some of the marked differences between captive and wild marmoset foraging strategies, foraging feeders were used in the present study. The current project examines the effects of four food distributions on the welfare of captive common marmosets: food centrally located in a stationary bowl, food in a bowl that changes location each day, hidden food in a clustered food source (cluster feeder), and hidden food in dispersed food sources (dispersed feeders). These four distributions were examined in four conditions with three intermediate conditions during which no additions were made to the typical room contents. These 'empty room' conditions were used to check possible order effects. The current study determined the behavioural effects of the four food distributions on activity, food apparatus use, eating, and self-directed and affiliative behaviours. The current study also determined whether food distribution altered the space use of the subjects in the short- and long-term.