Research ArticleBEHAVIORAL ECOLOGY

Kin-based cultural transmission of tool use in wild chimpanzees

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Science Advances  26 Apr 2017:
Vol. 3, no. 4, e1602750
DOI: 10.1126/sciadv.1602750
  • Fig. 1 Social transmission of cultural behavior in wild chimpanzees.

    (A) Probability of moss-sponging by subjects depending on whether they have at least one moss-sponger in the matriline: parameter estimates with SEs. (B) Probability of moss-sponging by subjects depending on their association history with other moss- or leaf-spongers in the group, calculated using the half-weight index (HWI): model estimates with SEs (shaded areas). The numerical results are provided in table S1.

  • Fig. 2 Proportion of trials with subjects using moss to manufacture a sponge.

    The size of the circles corresponds to the total number of trials observed (that is, the larger the circle is, the more trials the subject had). The red lines represent the means. Note that the figure represents raw data. Results of the generalized linear mixed model are provided in fig. S1 and table S1.

  • Fig. 3 Model of the two-dimensional transmission pattern.

    Circles represent all individuals seen moss-sponging at least once between 2011 and 2014. The eight original moss-spongers from Hobaiter et al.’s study (2) are represented in gray. The arrows represent the social transmission found by Hobaiter et al. (2). The rectangles represent matrilines in which vertical social learning took place, the main transmission mechanism involved in the spread. The dashed lines represent the possible learning path of the cases (n = 7) in which individuals acquired the behavior in the absence of vertical transmission because individuals did not have moss-sponging kin, suggesting learning from individuals that they were highly associated with (linked with the individual with the highest association index).

  • Table 1 List of participants sorted by matrilines and their choices during the experiment (number of leaf-sponging events, number of moss-sponging events, total number of sponging events, proportion of leaf-sponging, and proportion of moss-sponging). F, female; M, male.
    ID (N = 40)Age (years)SexMatrilineNo. of leaf-spongingNo. of moss-spongingTotalPercentage of leaf-spongingPercentage of moss-sponging
    AN24.3FAN*4041000
    CC14.3FCC*3031000
    GL38.3FG4041000
    GR8.3FG8081000
    HR5.0FH3474357
    HT36.5FH1452080
    HW21.3MH0110100
    HY9.1FH75125842
    IN15.3FIN*2136733
    JS8.4MJ0110100
    KG38.5FK12021000
    KI11.2FK10330100
    KP6.1FK12021000
    KC8.2MK22021000
    KL35.5FK23031000
    KH6.3FK33256040
    KS12.2MK31125050
    KU35.4FK30110100
    KB7.8FK41233367
    KR13.0FK40440100
    KW33.4FK40110100
    KZ19.8MK41011000
    KA15.8FKA*1011000
    MB5.9MM11011000
    ML39.5FM11011000
    MI7.0FM24158020
    MK34.4FM23256040
    MS23.3MN3031000
    NB52.3FN3147525
    NT11.6FN6061000
    OK18.5FOK*2021000
    PS16.3MPS*6178614
    RF7.3FR1125050
    RH49.5FR0440100
    RM12.1FR2021000
    RS17.0FR2136733
    TM10.5FTM*1125050
    UP15.3FUP*116176535
    ZD13.4MZ1011000
    ZG17.4MZG*1011000
    Median2137822.5
    Total9648144

    *Individuals without a known mother (they were assigned their own matriline).

    †Initial moss-spongers in the study of Hobaiter et al. (2).

    Supplementary Materials

    • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/3/4/e1602750/DC1

      table S1. Results of the generalized linear mixed model in the field experiment, with individual NT included as a potential demonstrator for moss-sponging.

      table S2. Results of the generalized linear mixed model in the field experiment, with individual NT included as a potential demonstrator for leaf-sponging (that is, if her moss-sponging event during an unrelated experiment is not taken into account).

      table S3. Individuals with a known sponging technique and their affiliation.

      fig. S1. General view of the clay pit located between the exposed roots of two adjacent trees (Cynometra alexandri and Mimusops bagshawei) consisting of two cavities.

      fig. S2. Closeup view of the two cavities.

      fig. S3. Histogram of parameter estimates for the factor moss-sponger in matriline.

      fig. S4. Histogram of parameter estimates for the factor average association with moss-spongers.

      movie S1. Manufacture of a moss-sponge.

      movie S2. Manufacture of a moss-sponge and a leaf-sponge.

    • Supplementary Materials

      This PDF file includes:

      • table S1. Results of the generalized linear mixed model in the field experiment, with individual NT included as a potential demonstrator for moss-sponging.
      • table S2. Results of the generalized linear mixed model in the field experiment, with individual NT included as a potential demonstrator for leaf-sponging (that is, if her moss-sponging event during an unrelated experiment is not taken into account).
      • table S3. Individuals with a known sponging technique and their affiliation.
      • fig. S1. General view of the clay pit located between the exposed roots of two adjacent trees (Cynometra alexandri and Mimusops bagshawei) consisting of two cavities.
      • fig. S2. Closeup view of the two cavities.
      • fig. S3. Histogram of parameter estimates for the factor moss-sponger in matriline.
      • fig. S4. Histogram of parameter estimates for the factor average association with moss-spongers.
      • Legends for movies S1 and S2

      Download PDF

      Other Supplementary Material for this manuscript includes the following:

      • movie S1 (.mp4 format). Manufacture of a moss-sponge.
      • movie S2 (.mp4 format). Manufacture of a moss-sponge and a leaf-sponge.

      Files in this Data Supplement:

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