Table 3. Relationships between nightly warbler and sparrow nocturnal flight call (NFC) detections and average regional nightly atmospheric or ambient noise conditions estimated via generalized additive models.
Warblers | Sparrows | ||||||
Variablea | Expected association | Estimate (SE) | t b | P c | Estimate (SE) | t b | P c |
Wind profit | + | 1.13 (0.08) | 14.99 | <0.001 | 1.01 (0.09) | 11.31 | <0.001 |
Wind speed | − | −0.91 (0.09) | −10.24 | <0.001 | −1.37 (0.10) | −13.57 | <0.001 |
Rain | − | −0.37 (0.09) | −4.08 | <0.001 | −0.47 (0.10) | −4.63 | <0.001 |
Cloud cover | + | 0.40 (0.08) | 4.77 | <0.001 | 0.24 (0.09) | 2.78 | 0.006 |
Visibility | − | −0.19 (0.07) | −2.66 | 0.008 | 0.00 (0.08) | 0.03 | 0.97 |
Noise | − | −0.16 (0.08) | −2.11 | 0.035 | −0.07 (0.08) | −0.81 | 0.42 |
Input variables were centered and scaled; thus, exponentiation of parameter estimates provides the average change in NFC detections per standard deviation change of the input variable. Standard deviations of input variables: wind profit (1.91 m/s), wind speed (1.53 m/s), rain (22.57%), cloud cover (35.27%), visibility (1.70 mi), noise (8.28 dB).
603 residual degrees of freedom.
Although the expected associations are one-directional, we report P from the two-sided test to avoid missing large differences in the unexpected direction [72].