Table 2.
Model-averaged coefficients (coef), unconditional standard errors (SE) and 95% confidence intervals (lower CI and upper CI) for the explanatory variables used for modeling the number of visits made by adult male ruby-throated hummingbirds competitors (NVC) at feeders potentially defended by a male in Cleveland County, Quebec (Canada), 2007–2009. The response variable was log-transformed and modeled using linear mixed models with feeder ID and the intercept and slope of spatial concentration for focal individual ID as random effects. Results are based on 88 focal individuals monitored for a total of 3326 bird-days and 15 037 bird-feeder-days.
| Variables | Coef | SE | Lower CI | Upper CI |
|---|---|---|---|---|
| Year 2008 | −0.09017 | 0.03778 | −0.16423 | −0.01612 |
| Year 2009 | −0.17854 | 0.04631 | −0.26931 | −0.08777 |
| Grid usage | 0.01735 | 0.00090 | 0.01560 | 0.01911 |
| nb of competitors | 0.34542 | 0.00571 | 0.33423 | 0.35660 |
| Feeder rank for males | 0.01531 | 0.00328 | 0.00889 | 0.02173 |
| Nectar sucrose concentration (high) | 0.51430 | 0.03940 | 0.43708 | 0.59152 |
| Spatial concentration | −0.20918 | 0.21631 | −0.63314 | 0.21479 |
| Daily nb of visits | −0.00028 | 0.00049 | −0.00123 | 0.00067 |
| Spatial stability | 0.15381 | 0.11210 | −0.06591 | 0.37353 |
| Openness (open) | 0.62874 | 0.20028 | 0.23620 | 1.02129 |
| Lateral visibility | 0.00347 | 0.00395 | −0.00427 | 0.01122 |
| Spatial concentration:daily nb of visits | −0.00587 | 0.00120 | −0.00822 | −0.00352 |
| nb of competitors:spatial concentration | 0.02693 | 0.01979 | −0.01186 | 0.06572 |
| Spatial concentration:spatial stability | −0.81189 | 0.31734 | −1.43387 | −0.18991 |
| Spatial concentration:feeder concentration (high) | 0.03809 | 0.13691 | −0.23026 | 0.30644 |
| Spatial concentration:openness (close):lateral visibility | −0.04051 | 0.01601 | −0.07189 | −0.00914 |
| Spatial concentration:openness (open):lateral visibility | 0.00744 | 0.00170 | 0.00411 | 0.01078 |