Table 1.

Climate variables used for the three types of distribution models

	Full models	Reduced model Poecile atricapillus	Reduced model Poecile carolinensis	Uncorrelated models
Annual Mean Temperature (Bio1)	✔	✔	✔	✔
Mean Diurnal Range in Temperature (Bio2)	✔	✔
Isothermality (Bio3)	✔
Temperature Seasonality (Bio4)	✔
Max Temperature of Warmest Month (Bio5)	✔	✔
Min Temperature of Coldest Month (Bio6)	✔
Temperature Annual Range (Bio7)	✔			✔
Mean Temperature of Wettest Quarter (Bio8)	✔			✔
Mean Temperature of Driest Quarter (Bio9)	✔
Mean Temperature of Warmest Quarter (Bio10)	✔		✔
Mean Temperature of Coldest Quarter (Bio11)	✔	✔
Annual Precipitation (Bio12)	✔		✔
Precipitation of Wettest Month (Bio13)	✔
Precipitation of Driest Month (Bio14)	✔		✔
Precipitation Seasonality (Bio15)	✔
Precipitation of Wettest Quarter (Bio16)	✔			✔
Precipitation of Driest Quarter (Bio17)	✔	✔	✔	✔
Precipitation of Warmest Quarter (Bio18)	✔
Precipitation of Coldest Quarter (Bio19)	✔
Altitude	✔