Relation between long call direction and subsequent travel directions.

<p>A) If travel direction and long call direction are independent of each other, we expect a uniform distribution of the deviation angles. The expected average deviation angle (in grey) would be 90°. B) On the other hand, if long call directions predict subsequent travel directions, the expected average deviation angle is significantly smaller than 90°.</p

Deviation angles between long call direction and travel direction after the first elicited long call of a day.

<p><b>Note.</b> For details, see Note of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0074896#pone-0074896-t001" target="_blank">Table 1</a>.</p

Deviation angles between direction of the last spontaneous long call given shortly before nesting and travel direction on the subsequent day.

<p><b>Note.</b> For details, see Note of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0074896#pone-0074896-t001" target="_blank">Table 1</a>. The median deviation angles are listed for all days, and subsets 1–3 separately. Subset 1 includes only those 26 days on which no new long call was given the next morning before 8:00 AM (Subset 2: before 9:00 AM, N = 18 days). Subset 3 includes only those 18 days in which the evening long call was not given in the direction of travel during the last hour before nesting on that day.</p

Deviation angles between long call direction and travel direction after the first spontaneous long call of a day.

<p><b>Note.</b> The table lists p-values of three different tests to evaluate whether deviation angles a between long call direction and subsequent travel direction differ significantly from 90°: a mixed-model (GLMM) with the random factor individual[male morph], a linear model (LM), and a non-parametric Wilcoxon signed-rank test (Wilcoxon). For the GLMM, %var denotes the percentage of variance explained by the random factor individual nested within male morph. If this value is smaller than zero, the GLMM result would not be reliable and is thus omitted (see Methods). The median deviation angles are listed for dominant male and the other adult males separately. For the median values, stars denote the level of significance (Wilcoxon): *: p<0.001, **: p<0.01, ***: p<0.001.</p

Deviation between evening long call direction and travel direction of the next day.

<p>The graph depicts the median of deviation angles between travel direction and the direction of the last spontaneous long call of the previous day, given shortly before nesting or from the nest. Time is clock time during the day following the long call. Statistics are given in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0074896#pone-0074896-t003" target="_blank">Table 3</a>.</p

Observed deviation between long call direction and subsequent travel direction.

<p>Median deviation angles for each time step are shown on a circular scale. A) On the same day, after the first spontaneous long call of a day. Time is number of hours elapsed after the long call is given. Statistics are given in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0074896#pone-0074896-t001" target="_blank">Table 1</a>. B) Variation between individuals: median deviation angles for each male, 5 h after a spontaneous long call. Sample size for each male is given in parentheses. C) On the same day, after the first elicited long call of a day. Time is number of hours elapsed after the long call is given. Statistics are given in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0074896#pone-0074896-t002" target="_blank">Table 2</a>. D) Differences between pairs of consecutive long calls: the original and a subsequent call. The subsequent (second) spontaneous long call predicts travel direction better than the original (first) spontaneous long call. If the second long call is elicited, however, it does not improve the prediction of travel direction. The deviation angles are averaged over four half-hour time steps after the second long call. Statistics are given in the text.</p

Object manipulation rates in immature male and female chimpanzees and bonobos.

<p>Mean object manipulation rates in bouts/hr (SD) for immature bonobos (left) and chimpanzees (right) according to sex (male = grey, female = white). * Independent Samples T-test: <i>P</i> < 0.05</p

Information on Wamba bonobo focal individuals (name, sex, age), community (grp.), name of mother, total observation time per individual, object manipulation rates and mean bout length.

<p>Information on Wamba bonobo focal individuals (name, sex, age), community (grp.), name of mother, total observation time per individual, object manipulation rates and mean bout length.</p

Object manipulation rates in immature chimpanzees and bonobos aged <3 yrs and >3 yrs old.

<p>Mean object manipulation rates in bouts/hr (SD) for immature bonobos (left) and chimpanzees (right) in two age classes (<3 yrs old = grey, >3 yrs old = white). * Independent Samples T-test: <i>P</i> < 0.05</p

Proportion of object manipulation bouts across manipulation types in immature chimpanzees and bonobos.

<p>Object manipulation bouts (%) across object manipulation types for immature bonobos (A) and chimpanzees (B); male and female bonobos (C, D) and chimpanzees (E, F); young (<3 yrs) and old (>3 yrs) immature bonobos (G, H) and chimpanzees (I, J).</p