ABSTRACT
During the last two decades an increasing amount of attention has been paid to the housing and care of monkeys and apes in laboratories, as has been done with the housing and care of other categories of captive animals. The purpose of this review is to develop recommendations for adaptations of housing and care from our knowledge of the daily behavioural activity of monkeys and apes in natural conditions and in enriched laboratory conditions. This review deals mainly with adaptations of daily housing and care with respect to behaviour, and it is restricted to commonly-used species: Callitrichidae (Callitrix jacchus, Saguinus oedipus); Cebidae (Aotus trivirgatus, Saimiri sciureus, Cebus apella); Cercopithecidae (Macaca fascicularis, M. mulatta, M. nemestrina, M. arctoides, Chlorocebus aethiops, Papio hamadryas, P. cynocephalus); Pongidae (Pan troglodytes).
Subject(s)
Animal Husbandry/methods , Animals, Laboratory/physiology , Behavior, Animal/physiology , Haplorhini/physiology , Animal Husbandry/standards , Animal Welfare/standards , Animals , Animals, Laboratory/psychology , Animals, Newborn , Female , Haplorhini/psychology , Male , Species SpecificityABSTRACT
Studies on the effects of rearing conditions on behavioural development showed that most monkeys reared with surrogate mothers persistently avoided a big novel object (paper bag) whereas most monkeys reared by natural mothers would approach it. Conditioned fear and conditioned avoidance, observational learning, and lack of support by the mothers' presence could be excluded as possible causes; we established that the high incidence of phobic behaviour in surrogate-reared groups was caused by deprivation of maternal care. Results of further studies showed that the avoidance was not restricted to the object the Ss had been exposed to in infancy; monkeys still avoiding the bag at 2 years also avoided other big novel objects. Some researchers have found differences in the neurobiological status between surrogate-reared monkeys and mother-reared monkeys. However, the results of our experiments showed that both types of rearing condition produced avoiders as well as non-avoiders. The question under discussion here is whether avoidance of novelty is a habit or a trait. The relative importance of features of surrogates versus real mothers, characteristics of infants and differences in mothering style is discussed.
ABSTRACT
Young monkeys were confronted with a harmless novel object in their familiar home-cage environment. The effects of two rearing conditions (mother and surrogate mother) and two confrontation conditions [presence and absence of the (surrogate) mother] upon the acquisition of phobic behaviour were studied. Most surrogate-reared monkeys showed persistent maladaptive avoidance behaviour with respect to the object during tests, from 7 months of age onwards. Most mother-reared monkeys approached the object during tests taking food near it, from 7 months onwards. The confrontation condition had no effect upon behaviour with respect to the object. As no aversive conditioning procedures have been applied, merely presenting a harmless object appears to be enough to set off persistent avoidance in surrogate-reared monkeys. Further investigation of the origin of the phobic behaviour is interesting in view of developing animal models of human phobias of which no conditioning history is known.
Subject(s)
Disease Models, Animal , Maternal Deprivation , Phobic Disorders/psychology , Animals , Exploratory Behavior , Macaca fascicularisABSTRACT
In previous studies surrogate reared cynomolgus monkeys have been shown to become phobic of an unprepared harmless object. In the present study an attempt was made to prevent the development of phobic behaviour in young monkeys and to extinguish avoidance behaviour in phobic monkeys. In the first experiment subjects were exposed to the object in company of their (surrogate) mothers which approached the object. In the second experiment phobic subjects were exposed to the object in company of non-phobic conspecifics which approached the object. The results of the first experiment show that modeling was unsuccessful in preventing the acquisition of phobia in the surrogate-reared monkeys but seemed successful in accelerating approach in the mother-reared subjects. The results of the second experiment show that during the modeling treatment the phobic subjects followed the model and approached the object. However, in post treatment tests all subjects but one relapsed into avoidance. The effect of modeling during treatment is interpreted in terms of coactive facilitation.
Subject(s)
Extinction, Psychological , Fear , Imitative Behavior , Animals , Arousal , Avoidance Learning , Female , Macaca fascicularis , Male , Social EnvironmentABSTRACT
Fifty-two cynomolgus monkeys were reared in peer groups on surrogate mothers and fed by bottle during the first months of life. A description of the technique of bottle feeding and the structure of surrogate mothers is presented. Results are shown in a growth curve. Inter-individual differences in body weight were very large. The mean weight was higher in males than in females, but no significant sex differences in growth occurred. The weight of mother-reared infants stayed within the standard deviation of the mean weight of the artificially-reared subjects.
