Field Evidence Suggests That Some Migrant Loggerhead Shrikes Breed on Wintering Grounds

I describe evidence gathered over 25 years of in-hand examination for banding free-flying loggerhead shrikes (Lanius ludovicianus) in the field.Nestlings were not studied nor banded.Close examination of plumage, molt, wing and tail measures gives more precise information than any other means.Although I sometimes encountered young birds of questionable age during spring migration in Colorado, this winter-breeding hypothesis did not emerge until finding nestling shrikes in Texas in January and February.Then, combined with the capture of young shrikes in late February and April in Colorado, this hypothesis was created.