Using isoscapes to track animal migration

Abstract

Movement patterns and annual migrations of animals are vital components of their ecology but have generally been poorly studied due to fundamental limitations in using exogenous markers. Stable isotope measurements of animal tissues represent endogenous markers that can provide information on origins because they reflect isoscape patterns occurring at various scales. In cases where animals move among isotopically distinct regions or over isotopic gradients, the isotopic measurement of a tissue representing the appropriate period of dietary integration can be used to place animals spatially and temporally. Detailed information on animal ranges, isoscape pattern and the dynamics of isotopic turnover in various tissues allows the placement of individuals or populations to solution space within isoscapes. Basic principles and examples of tracking migratory animals using stable isotopes are provided with particular emphasis on the use of the stable isotopes of the elements C, N, H, O and Sr. Improvements in our understanding of the factors causing annual deviations from isoscape patterns based on long-term datasets are needed to improve resolution of placing animals to origins. © 2010 Springer Science+Business Media B.V.