Candidate models examining factors influencing the species richness of birds on roadside right-of-ways in west-central Illinois, USA.

Number of parameters (k), AICc, change in AICc (ΔAICc), and AICc weights (AICcWt) are reported. Models include variables for the height of non-woody vegetation (Height), visual obstruction (VO), non-linear response to visual obstruction (VO-nonlinear), ROW width (ROW), the combined width of ROWs on both sides of the road (ROWtotal), soil compaction (Soil), forb cover (Forb), grass cover (Grass), an index of vegetative biomass (Biomass), average annual daily traffic (AADT), synergistic effect of ROW width and traffic (SYN), and the presence or absence of perches for birds (Perch).Candidate models examining factors influencing the species richness of birds on roadside right-of-ways in west-central Illinois, USA.