Species: Vireo gilvus

BREEDS: British Columbia, southern Mackenzie, central Saskatchewan, southern Manitoba, western Ontario, northern Minnesota, northern Michigan, southern Ontario, southern Quebec, southern Maine, southeastern New Brunswick and Nova Scotia, south to Baja California, northern Mexico, Texas, southern Louisiana, northern Alabama, western North Carolina, and southeastern Virginia. WINTERS: northern Mexico to Nicaragua, casually to Costa Rica (Stiles and Skutch 1989). GILVUS: breeds from southwestern Alberta, central Saskatchewan and southern Manitoba east across extreme southern Canada to New Brunswick, and south to southeastern Texas, southern Louisiana (formerly), central Mississippi, northern Alabama, southeastern Tennessee, western North Carolina, and Virginia, west to southeastern Montana, northern and eastern North Dakota, eastern South Dakota, eastern Nebraska, Kansas, and southeastern Colorado; winters in Mexico and northern Central America south to northeastern Costa Rica (Sibley and Monroe 1990). SWAINSONI: breeds from southeastern Alaska, northern British Columbia, west-central and southwestern Mackenzie, western and northern Alberta, central Wyoming, southwestern South Dakota, and western Nebraska south to southern California, southern Nevada, central and southeastern Arizona, mountains of Mexico (to Mexico, Morelos, central Oaxaca), southern New Mexico, wetsern Texas, and Colorado (except southeast), and southern Baja California; winters in Mexico and northern Central America south to El Salvador (Sibley and Monroe 1990).