Table 1 Descriptive data.

From: Chimpanzee drumming: a spontaneous performance with characteristics of human musical drumming

 

Descriptive data

Ljung-Box Test

Auto-correlation for the next n beats (b)

Dynamics

 

Mean Inter-beat (Ib) Duration (in ms)

min Ib Duration (ms)

max Ib Duration (ms)

Total N° of beats

Value (a)

khi

Pvalue(at 1rst lag)

 

T value

R Square

P

Seq1

212.9

95

432

155

15

14.52

<0.01

2

4.17

0.09

<0.01

Seq2

253.9

86

489

34

na

0.09

0.76

na

−0.45

−0.02

0.66

Seq3

211.9

53

1156

34

na

0.12

0.72

na

0.69

−0.01

0.49

Seq4

222.7

130

312

47

15

16.5

<0.01

12

0.17

−0.02

0.87

Seq6

217.3

88

617

57

1

6.57

0.03

1

1.78

0.04

0.08

Seq7

267.4

79

470

71

na

0.37

0.54

na

0.1

0.0001

0.32

Seq8

274.6

96

1048

28

na

0.48

0.48

na

1.23

0.02

0.229

Seq9

258.2

66

709

71

15

9.8

<0.01

4

3.05

0.11

0.01

Seq10

276.3

96

421

32

na

0.002

0.96

na

−0.9

−0.01

0.37

Seq11

253.8

98

726

155

15

29.09

<0.01

10

2.37

0.03

0.02

  1. Descriptive data on inter-beat (Ib) duration, number of beats, value and results of the Ljung-Box test, the auto-correlation test and the dynamic results for each sequence.
  2. For example, in Sequence 1, the Ljung-Box test indicates a significantly non-random pattern at the first lag, checking for the next lags indicates that non-random patterns are detectable within up to 15 lags (Supplementary Fig. S2). The autocorrelation test indicates that whatever the position in the sequence, the time at which the next 2 beats will occur can be predicted (Supplementary Fig. S3). Here, the dynamic analysis shows a significantly positive linear trend, thus an increase in the duration between two beats (deceleration).
  3. (a)Number of lags within which non-random patterns can be detected (Supplementary Fig. S2).
  4. (b)Number of beats where dependency between two beats is statistically significant (Supplementary Fig. S3).