Environmental Studies Program


Date of this Version

Spring 5-2011


Stable-hydrogen isotopes are becoming an increasingly popular method of studying migratory birds, though sample preparation methods may affect results. In this study I examined feathers from red-tailed hawks (Buteo jamaicensis) to determine the relationship between measure of δD due to inter-feather variation or drying methods, assessed the accuracy of results by using two birds of known-origin and estimated possible natal origins of migratory red-tailed hawks. Two feathers per individual were taken from 81 wild hawks caught at Hitchcock Nature Center near Crescent IA and from 2 rescued red-tailed hawks, Raptor Recovery Nebraska near Eagle, NE. 119 of the collected feathers were used. I found that there was no significant inter-feather variation, and that there was no significant difference between air-drying and oven-drying feathers. δD results of the known-origin birds corresponded with Eagle and the origin of their food (Madison, WI). Maps were constructed using ArcGIS that display possible origins of wild birds and known-origin birds based on δD of their feathers.