Supporting Information File

We analyzed stable-hydrogen (<i>δ</i>²H), carbon (<i>δ</i>¹³C) and nitrogen (<i>δ</i> ¹⁵N) isotope ratios in feathers to better understand the molt origin of European starlings (<i>Sturnus vulgaris</i>) collected at dairies and feedlots throughout the United States. Primary feathers were used from 596 adult and 90 juvenile starlings collected during winter at dairies and feedlots that experience bird damages in Arizona, California, Colorado, Idaho, Illinois, Iowa, Kansas, Minnesota, Missouri, Nebraska, Nevada, New Hampshire, New Mexico, New York, North Carolina, Oregon, Texas, Vermont, Washington and Wisconsin.