Table 2.
Outputs of the full GLMMs relating the effects of COVID-19 confinement measures (alongside covariates) on NDSI, biophony (here, probability of bird calls) and anthropophony (here, probability of engine noise) levels at 08:00 am.
| Response variable | Explanatory variable | Estimate | SE | Z value | P value |
|---|---|---|---|---|---|
| NDSI | Intercept | 0.121 | 0.243 | 0.497 | 0.619 |
| Confinement level 1 vs no measures | 0.035 | 0.012 | 2.832 | 0.005** | |
| Confinement level 2 and 3 vs no measures | 0.051 | 0.014 | 3.535 | <0.001*** | |
| PCA axis: degree of anthropization | −0.190 | 0.052 | −3.645 | <0.001*** | |
| Julian day: season | −0.083 | 0.005 | −17.930 | <0.001*** | |
| Climate: dry vs tropical | 0.498 | 0.366 | 1.358 | 0.174 | |
| Climate: temperate vs tropical | 0.018 | 0.230 | 0.077 | 0.938 | |
| Climate: continental vs tropical | 0.023 | 0.276 | 0.082 | 0.934 | |
| Birds | Intercept | −2.408 | 0.264 | −9.137 | <0.001*** |
| Confinement level 1 vs no measures | 0.083 | 0.013 | 6.191 | <0.001*** | |
| Confinement level 2 and 3 vs no measures | 0.207 | 0.015 | 14.074 | <0.001*** | |
| PCA axis: degree of anthropization | −0.115 | 0.044 | −2.595 | 0.009** | |
| Julian day: season | −0.131 | 0.005 | −28.449 | <0.001*** | |
| Climate: dry vs tropical | 0.381 | 0.353 | 1.079 | 0.281 | |
| Climate: temperate vs tropical | −0.153 | 0.238 | −0.642 | 0.521 | |
| Climate: continental vs tropical | −0.136 | 0.287 | −0.476 | 0.634 | |
| Engine noise | Intercept | −4.844 | 0.207 | −23.445 | <0.001*** |
| Confinement level 1 vs no measures | −0.033 | 0.011 | −2.887 | 0.004** | |
| Confinement level 2 and 3 vs no measures | −0.216 | 0.014 | −15.130 | <0.001*** | |
| PCA axis: degree of anthropization | 0.091 | 0.049 | 1.845 | 0.065 | |
| Julian day: season | 0.054 | 0.005 | 10.839 | <0.001*** | |
| Climate: dry vs tropical | −0.220 | 0.351 | −0.626 | 0.531 | |
| Climate: temperate vs tropical | 0.022 | 0.220 | 0.100 | 0.920 | |
| Climate: continental vs tropical | −0.152 | 0.265 | −0.573 | 0.566 |
Δ AIC values between the full and the null models are, from top to bottom, 593, 2056 and 1023, thus indicating that the full models were more informative than the null ones. SE: standard error of the estimate. ***P < 0.001, **P <0.010, *P < 0.050. Confinement level 1 calls for “recommended not to leave home” and Confinement level 2 and 3 calls for “not allowed to leave home”.