Table 2. Effect size and P in Evohution of the syrinx of Apodiformes * inchuding the vocah-hearning Trochihidae (Aves: ºtrisores)

Table 2. Effect size and P -value of PGLS regression models built between select pairs of variables measured in our study. For regressions of acoustic traits on morphoanatomical traits, only traits recovered as contributing to significantly correlated principal components (see text) were included. Abbreviations of morphoanatomical traits: BM, body mass; DTL, distance tracheolateralis–labia; IMCSA, intrinsic muscle cross-sectional area; LL, labia length; TD, tracheal diameter; TER, tracheal elongation ratio; TLCSA, tracheolateralis cross-sectional area (see Main Text for definitions). Abbreviations of acoustic traits: fmax_song: maximum vocalization frequency; fpeak_mean: peak frequency; range_song: vocalization frequency bandwidth (see introduction vignette of R package ‘bioacoustics at https://cran.r-project.org/ web/packages/bioacoustics/vignettes/introduction.html.). Regressions of morphoanatomical traits onlyRegression formulaPseudo R-squaredP -valueDTL~BM0.0483.1780824TLCSA~BM0.5708.0000453***LL~BM0.1662.0377686*TER~BM–0.0593.7517170TD~BM0.7875.0000001***IMCSA~BM0.4123.0058657**DTL~TLCSA0.3132.0060599**LL~DTL0.0740.1299169DTL~TER0.4662.0021327**IMCSA~DTL0.5839.0008855***TLCSA~TER–0.0429.5675364TLCSA~TD0.5743.0000656***IMCSA~TLCSA0.4257.0049952**LL~TER0.3585.0065616**LL~TD0.1461.0539913LL~IMCSA0.6011.0004149***IMCSA~TER–0.0247.4170967IMCSA~TD0.5474.0015014**Regressions of acoustic traits on morphoanatomical traitsRegression formulaPseudo R-squaredP -valuefmax_song~TER0.2417.0360931*range_song~TER0.2006.0534005fpeak_mean~TER0.1532.0827486fmax_song~TD0.0194.2789385range_song~TD–0.0291.4507599fpeak_mean~TD0.1297.1024637