Social competence of adult chimpanzees (Pan troglodytes) with severe deprivation history: I. An individual approach.

Abstract

Early social deprivation in highly social mammals interferes with their varying needs for security and stimulation. Toleration of social stimulation was studied in 18 adult ex-laboratory chimpanzees, who had been deprived for 16 to 27 years, during their 1st year after resocialization into 1 of 3 social groups. For this, a model of social competence was developed with 5 grades of social stimulation. The chimpanzees were classified as either early deprived (EDs; M = 1.2 years) or late deprived (LDs; M = 3.6 years) according to their age at entering the laboratory. EDs did not differ significantly from LD chimpanzees in the first 3 grades of social stimulation (i.e., the toleration of stationary vicinity, initiation of brief sociopositive contacts and gentle social play). LDs, however, clearly exceeded EDs in the 4th and 5th grade of social stimulation (i.e., their engagement in allogrooming and their toleration of passive close proximity). Furthermore, LDs showed greater social initiative in changing a social situation and had more expanded grooming networks compared with EDs. Moreover, in LDs and ED females, but not in ED males, toleration of stationary vicinity increased from the 1st to the 2nd year of group living.

Long-Term Evaluation of Abnormal Behavior in Adult Ex-laboratory Chimpanzees (Pan troglodytes) Following Re-socialization

“…Moreover, consistent with our findings with respect to social behavior [12,55,56], age at onset of infantile deprivation had an impact on the overall levels of behavioral aberrancies as well. Except for coprophagy, which was more widespread among females compared to males, no sex differences were found.…”

Characterizing abnormal behavior in a large population of zoo-housed chimpanzees: prevalence and potential influencing factors

“…Mother-reared chimpanzees are likely to have more exposure to other chimpanzees who display coprophagy than those chimpanzees raised in a human setting (nursery or privately owned individuals typically live in smaller groups and their companions are less likely to show coprophagy), so the opportunity to learn this behavior socially may be heightened. In addition, mother-reared chimpanzees typically have more developed social skills than those raised in nurseries or by humans (Spijkerman et al, 1997; Baker et al, 2000; Kalcher-Sommersguter et al, 2011) which may allow them to better learn behaviors from their mothers and others in their social groups. For these two reasons we would expect these individuals to be more likely to learn a behavior like coprophagy.…”

“…For these two reasons we would expect these individuals to be more likely to learn a behavior like coprophagy. Also, given what we know about the negative welfare outcomes for non-mother-reared chimpanzees (Fritz et al, 1992; Nash et al, 1999; Martin, 2002; Kalcher-Sommersguter et al, 2011), if coprophagy was an indicator of negative welfare, we would expect to see these chimpanzees exhibit more of this behavior. Indeed the opposite trend is true in our sample, suggesting that coprophagy rates have relatively little to do with welfare.…”

Rehabilitation and Socialization of Chimpanzees (Pan troglodytes) Used for Entertainment and as Pets: An 8-Year Study at Fundació Mona

“…Several studies have determined that chimpanzees with a previous history of maltreatment or unfavorable rearing conditions can be rehabilitated and resocialized over time (Kalcher-Sommersguter et al 2013;Kalcher et al 2008). However, most of this evidence comes from former laboratory chimpanzees (Reimers et al 2007), where chimpanzees that were caged singly at an early age (mean 1.2 yr) present higher levels of social competence than those caged singly at a later age (mean 3.6 yr) (Kalcher-Sommersguter et al 2011).…”