We use cookies to ensure that we give you the best experience on our website. You can change your cookie settings at any time. Otherwise, we'll assume you're OK to continue.

Durham University

Research & business

View Profile

Publication details for Professor Stephen G Willis

Font, L., Nowell, GM., Pearson, DG., Ottley, C. & Willis, SG. (2007). Sr isotope analysis of bird feathers by TIMS: a tool to trace bird migration paths and breeding sites. Journal of Analytical Atomic Spectrometry 22(5): 513 - 522.

Author(s) from Durham


Here we present a methodology to analyse 87Sr/86Sr isotope ratios in bird feathers with very low
Sr concentration using ultra-low blank ion-exchange chemistry combined with thermal ionisation
mass spectrometry. For this study, Sedge Warbler (Acrocephalus schoenobaenus) feathers were
used from four different locations within Europe. Prior to analyses, dust particles from the
feathers� surface were removed with nitrogen gas. The shaft and the vane parts of the feather
were analysed separately. Generally, the vane had higher trace element abundances compared to
the shaft. The vane contained between 3 ng and 12 ng of Sr and the shaft between 0.5 ng and 3
ng of Sr. Due to the small amount of Sr in the feathers, small loads (0.5�12 ng Sr) of
international standard NBS 987 were analysed for 87Sr/86Sr isotope ratios giving an average of
0.710263  0.000013 (2s) (n = 177) and an external reproducibility below 0.002%. The 87Sr/86Sr
isotope data of samples and standards with o6 ng of Sr were collected using a protocol whereby
data collection was started very early, when the 88Sr intensity was often o20 mV. The filament
current and hence 88Sr intensity, was increased throughout data collection and the 86Sr/88Sr ratio
was continually monitored to assess mass fractionation. Data were then exported and evaluated
offline in a time-resolved sense for the 88Sr and 87Rb intensities and 87Sr/86Sr isotope ratios. The
87Sr/86Sr isotope ratios of the cleaned Sedge Warbler feathers varied geographically and were
indicative of the different geology in the locations where the feathers were grown.