Article

The Price of Play: Self-Organized Infant Mortality Cycles in Chimpanzees

Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
PLoS ONE (Impact Factor: 3.53). 02/2008; 3(6):e2440. DOI: 10.1371/journal.pone.0002440
Source: PubMed

ABSTRACT Chimpanzees have been used extensively as a model system for laboratory research on infectious diseases. Ironically, we know next to nothing about disease dynamics in wild chimpanzee populations. Here, we analyze long-term demographic and behavioral data from two habituated chimpanzee communities in Taï National Park, Côte d'Ivoire, where previous work has shown respiratory pathogens to be an important source of infant mortality. In this paper we trace the effect of social connectivity on infant mortality dynamics. We focus on social play which, as the primary context of contact between young chimpanzees, may serve as a key venue for pathogen transmission. Infant abundance and mortality rates at Taï cycled regularly and in a way that was not well explained in terms of environmental forcing. Rather, infant mortality cycles appeared to self-organize in response to the ontogeny of social play. Each cycle started when the death of multiple infants in an outbreak synchronized the reproductive cycles of their mothers. A pulse of births predictably arrived about twelve months later, with social connectivity increasing over the following two years as the large birth cohort approached the peak of social play. The high social connectivity at this play peak then appeared to facilitate further outbreaks. Our results provide the first evidence that social play has a strong role in determining chimpanzee disease transmission risk and the first record of chimpanzee disease cycles similar to those seen in human children. They also lend more support to the view that infectious diseases are a major threat to the survival of remaining chimpanzee populations.

Download full-text

Full-text

Available from: Peter D Walsh, Mar 20, 2015
1 Follower
 · 
74 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Social relationships vary in content, quality and patterning. Most researchers focus on whether and how nondispositional factors, including age, sex, kinship and rank, predict variance in the content, quality and patterning of relationships. However, within a species, these factors do not always predict partner choice. We examined whether similarity in any of five personality traits, Assertiveness, Openness, Neuroticism, Sociability and Attentiveness, independently contributed to variation in the affiliative and agonistic re- lationships of pairs of brown capuchin monkeys, Sapajus sp. Capuchins that were more similar in Neuroticism had higher affiliative relationship scores, while capuchins that were more similar in Sociability shared overall higher-quality relationships (i.e. the difference between the dyad's affiliative and agonistic scores). These effects were independent of age, sex, kinship and rank, suggesting that certain aspects of the psychology of these animals may contribute uniquely to the quality of their social relationships.
    Animal Behaviour 07/2015; DOI:10.1016/j.anbehav.2015.04.013 · 3.07 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We described the relationship between relatedness as full or maternal half siblings and expression of social play and other social behaviors in juvenile Belding’s ground squirrel (Urocitellus beldingi) litters and evaluated the possible role of play in establishing social bonds between juvenile females. We used microsatellite analysis to determine relatedness. Juvenile females did not interact preferentially with full over half siblings, suggesting that they may form bonds equally with full and half sisters. The probability that females will have a surviving full sister beyond the juvenile period may be low in U. beldingi, and establishing a cooperative relationship with a half sister may sometimes be the best available option in adulthood. As the proportion of females within litters increased, rates of play decreased, suggesting that low social play may be adequate for social bonding among females. Among juvenile male U. beldingi, play bouts lasted longer between full than half brothers; however, juvenile males did not interact preferentially with full brothers in play or other social interactions. Body mass differences were smaller between full than half brothers, and in both full and half brother pairings, play bouts lasted longest when body mass differences were small. Because male U. beldingi do not ordinarily interact with littermate siblings after emigrating from the natal area, it is unlikely that play behavior functions to establish long-term social bonds between full brothers. Rather, young males may favor play interactions with phenotypically similar partners who can provide optimal challenges in interactions that promote motor development.
    Behavioral Ecology and Sociobiology 11/2014; 69(3). DOI:10.1007/s00265-014-1848-y · 3.05 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Although the approach of contact network epidemiology has been increasing in popularity for studying transmission of infectious diseases in human populations, it has generally been an underutilized approach for investigating disease outbreaks in wildlife populations. In this paper we explore the differences between the type of data that can be collected on human and wildlife populations, provide an update on recent advances that have been made in wildlife epidemiology by using a network approach, and discuss why networks might have been underutilized and why networks could and should be used more in the future. We conclude with ideas for future directions and a call for field biologists and network modelers to engage in more cross-disciplinary collaboration.
    Interdisciplinary Perspectives on Infectious Diseases 03/2011; 2011:676949. DOI:10.1155/2011/676949