Analyses of Original Movement-Pattern Variables in Sham Trials

Supplementary Material 1. Analyses of original movement-pattern variables in sham trials.

During sham trials, we examined female behavior in the test arena in the absence of acoustic stimulation and in the presence of our chorus-shaped maskers broadcast from the overhead speaker. In sham trials, no target signal was broadcast from speakers on the floor. To determine the extent to which female behavior was differentially affected by the different maskers, we compared female movement patterns across treatments. Using the animal tracking software Ethovision v3.1 (Noldus 2005), we measured (i) the total distance moved by the subjects (in cm), (ii) the average velocity of their movements (in cm/s), (iii) the average turn angles (in degrees), and (iv) the meander (in degrees/cm), which quantifies changes in direction of movements relative to the distance moved (see Bee and Riemersma 2008). These variables were correlated (Table SM1) and the results of principal component analysis (PCA) are reported in the main manuscript. Here, we provide results of the analyses on the raw variables.

Results from analyses of the original movement-pattern variables parallel those on the two factors of the principal component analysis. As stated in the main manuscript, PCA factor 1 loaded with variables describing angular movement: average turn angle and meander. We found no differences across treatments in the average turn angle (H9, 58 = 6.48, P = 0.69), or meander (H9, 58 = 9.34, P = 0.41) during sham trials (Figure SM 1a, b). PCA factor 2 loaded with variables describing non-angular movements: distance moved and velocity. There were no differences across treatments in the total distance moved

(Kruskal-Wallis test: H9, 58 = 3.27, P = 0.95) or the average velocity (H9, 58 = 9.54, P = 0.39) (Figure SM 1c, d). These results suggest that female behavior in the test arena was not differently affected by the type of masker broadcast from the overhead speaker. Furthermore, our results show that female movement patterns in the presence of chorus-shaped noises were not different than those in the absence of sound.

References

Bee MA, Riemersma KK (2008) Does common spatial origin promote the auditory grouping of temporally separated signal elements in grey treefrogs? Animal Behaviour 76:831-843.

Noldus (2005) EthoVision® Video Tracking System for Automation of Behavioral Experiments: Reference Manual Version 3.1. Noldus Information Technology, Wageningen, The Netherlands. Table SM 1. Correlations between the four original movement-pattern variables. Turn angle Meander Velocity Distance moved (cm) (degrees) (degrees/cm) (cm/s) Turn angle (degrees) 1.00 0.87 0.24 -0.10 Meander (degrees/cm) 0.87 1.00 0.05 -0.27 Distance moved (cm) 0.24 0.05 1.00 0.34 Velocity (cm/s) -0.10 -0.27 0.34 1.00

Figure SM 1. Movement patterns in the sham trials. Shown here are the median (point), inter-quartile range (box), and non-outlier range (whiskers) for average turn angle (a), meander (b), total distance moved (c), and average velocity (d) in each treatment. Sample sizes for each treatment are 5 in the Non- fluctuating noise (Nf), 7 in the No-noise (Nn), 2 in the 0.625 Hz SAM noise (0.625), 8 in the 1.25 Hz SAM noise (1.25), 10 in the 2.5 Hz SAM noise (2.5), 5 in the 5 Hz SAM noise (5), 5 in the 10 Hz SAM noise (10), 4 in the 20 Hz SAM noise (20), 5 in the 40 Hz SAM noise (40), and 7 in the 80 Hz SAM noise (80) treatments.