Arnold S. Chamove

Cage design reduces emotionality in mice

To see if a more natural cage design would alter the reactivity of laboratory mice, 192 mice were reared in cages with (1) no dividers, (2) five vertical dividers, (3) nine vertical dividers, or (4) nine vertical dividers and one horizontal platform. The mice preferred the most complex cages, and on almost all measures they were less emotional when reared in the more complex cages. Results suggest that a more natural housing environment would lead to healthier animals.

Social and environmental influences on self-aggression in monkeys

Three studies of stumptailed macaques examined the occurrence of self-aggression (SA) under different housing conditions. In group tests those environmental manipulations which increased social aggression decreased SA, but similar environmental conditions were found to increase SA in monkeys when tested in individual cages. SA increased in a group of monkeys in response to a temporarily impoverished environment. Like stereotyped movements reported for other species, SA may increase sensory input in poor environments, but this is probably not true for group-living monkeys, in which SA appears to be primarily a form of redirected social aggression.

Transmission of B virus infection between monkeys especially in relation to breeding colonies

Studies of B virus (Herpesvirus simiae) antibody in several species of macaque lead to the following generalizations. Newborn monkeys are not infected with B virus, even when born of seropositive mothers. Young monkeys remain uninfected until they become adults. The majority of adults develop B virus antibody unless their physical contact with seropositive adults is restricted. These observations are consistent with sexual transmission of B virus and classification of the disease in monkeys as venereal. However, infection at oral and dermal sites also occurs and may play a part in monkey-to-monkey transmission. Epizootics of B virus occurred during early attempts to start B virus-free breeding colonies. They appeared to originate from reactivated latent B virus in adult monkeys which had only low titres of antibody. The stress produced when groups of adult strangers were assembled to form breeding colonies was the most effective known inducer of latent B virus. Total exclusion of animals with any trace of antibody has enabled the establishment of new breeding colonies which are free from B virus.

Are alarming events good for captive monkeys

Abstract To evaluate a hypothesis suggesting that brief arousal may be beneficial to laboratory animals, 39 cotton-top tamarins living in four families were observed following stimulating husbandry procedures. Arousal led to an improvement in behaviour (i.e. decrease in activity and an increase in affiliation) during the remainder of the day, changes similar to patterns reported as positive effects of enrichment but opposite to negative effects of long-term stressors; a wider range of normal behaviour; but we found no evidence for an improved response to challenge.

Role or dominance in macaque response to novel objects

Forty-four juvenile rhesus, 30 stumptailed, and 6 pigtailed monkeys were tested individually and in stable quadrads for time to contact slightly and highly novel objects. When peer-group tested, dominant monkeys were the first to contact the slightly novel but not the highly novel objects, unlike preferences found when they were tested individually. A role analysis revealed better contact-order prediction, most groups having their habitual first contactor. When this contactor was overtly punished or covertly trained to avoid the object, group response was altered. The use of the termrole is discussed in detail, concluding that a role involves a particular individual who is expected to interact with others while in certain groups to complete some beneficial function.

Self-aggressive Behaviour in Monkeys

Self-aggression (SA) in nonhuman primates is a deviant form of aggression which involves threats and physical attacks directed towards the self. SA sometimes causes tissue damage, but usually the skin is not broken. The behaviour is most often reported in some Old World monkeys that have been reared under conditions of social deprivation, and rarely occurs in the wild. It may also appear in normal animals under very stressful conditions. Like social aggression, SA is more prominent in males; it increases with the onset of puberty, and may decline in later adulthood. In addition, like social aggression, SA may increase in response to pain, frustration, fear, or sexual arousal. It is hypothesized that SA develops in socially restricted infant monkeys due to potent ‘sign stimuli’, provided by the animal’s own body combining with the infant’s general reliance on the self, which has derived from other self-directed behaviours, such as sucking, clasping, and playfighting. SA may persist after social housing because animals learn that there are fewer social, physical and energetic costs involved in using the self, rather than another group member, as an outlet for aggression. Species that rely less on redirection in aggressive contexts, and/or possess self-awareness, appear less susceptible to SA of this type.

Establishment of a breeding colony of stumptailed monkeys (Macaca arctoides)

A breeding colony of 27 female and 4 male stumptailed monkeys was established in a 300 m2 laboratory. More than 80 infants were born over 6 years.

Infant stumptailed macaques reared with mirrors or peers: social responsiveness, attachment, and adjustment

Comparisons of activity toward mirrors and peers in infant macaques being reared with one of these stimuli as the primary rearing partner revealed markedly greater social responsiveness to a fully accessible cagemate than to ones own reflection. Measures of exploration, aggression, and especially play all revealed the cagemate to be the more potent social stimulus. Mirror-reared infants given additional experience of a live peer behind a transparent partition were less responsive to the mirror than were infants with no social stimulation other than a mirror. In contrast, cagemate-directed behavior of peer-reared infants was not seriously affected by additional exposure to a mirror. A fully accessible peer also elicited more social responding than a peer behind a transparent partition, and infants with experience of both a live cagemate and mirrors were generally more responsive toward the former. Greater agitation in peer-reared than in mirror-reared stumptailed monkeys during separations from their rearing partners suggests that exposure to the physically accessible partner led to stronger attachments. Infants reacted positively to a moderately unfamiliar environment but showed behavioral disruption when placed in a very unfamiliar environment. Disruption was especially evident in peer-reared infants, in which exposure to the unfamiliar environment was compounded with the absence of the attachment figure. Mirror-rearing appeared to reduce the tendency toward ‘isolation syndrome’ behaviors compared to alone-rearing, and these behaviors appear to be less common in stumptailed than in rhesus macaques.

Self-aggression, stereotypy and self-injurious behaviour in man and monkeys

Self-aggression (SA) in monkeys is sometimes referred to as an animal analogue of self-injurious behaviour (SIB) in humans. However, the initiating and maintaining conditions of SA, along with other considerations, make it unlikely that SA can serve as a very useful model of human SIB. Instead, another, more widespread behaviour in nonhuman primates, namely stereotypy, appears to share more in common with human SIB and therefore seems likely to provide a more suitable model. It is concluded that SA is interesting from the point of view of the study of aggression, and that greater understanding of it should have theoretical and practical consequences.

Nongenetic induction of acquired levels of aggression.

Chamove, A.S. and Moodie, E.M., 1990. Are alarming events good for captive monkeys? Appl. Anim. Behav. Sci., 27: 169-176. To evaluate a hypothesis suggesting that brief arousal may be beneficial to laboratory animals, 39 cotton-top tamarins living in four families were observed following stimulating husbandry proce¬ dures. Arousal led to an improvement in behaviour (i.e. decrease in activity and an increase in affili¬ ation ) during the remainder of the day, changes similar to patterns reported as positive effects of enrichment but opposite to negative effects of long-term stressors; a wider range ofnormal behaviour; but we found no evidence for an improved response to challenge.