Biomarkers for migration research

Description

The H and O isotope ratios of many tissues from migratory animals exhibit relationships with the isotopic composition of local environmental water. As such, isotopes can be used as inherent tracers of animal movement. The relationships observed in natural systems are highly variable and noisy, however, leaving open the question of whether further ecological information is recorded in these tissue/environment relationships. Previous work in human and invertebrate systems suggests that regional or temporal dietary variation can be identified and quantified using data from these isotopic systems, but relatively little is known about the strength, ubiquity, and applicability of these relationships within migratory systems.

This project supported postdocs who develop, tested, and improved models for isotope-based tracking of animal migration.

Among the key questions addressed were:

• Do relationships between the isotope ratios of tissues and local environmental materials preserve information on patterns of biological (e.g., dietary ecology, metabolic rate) and environmental variation?
• Can reliable models for characterization of this variation over multiple spatial scales and among taxa be developed based on spatial isotopic datasets and models?
• Do predictable spatiotemporal relationships exist between environmental forcers (e.g., agriculture, urbanization, drought) and isotopic 'indicators' for biology and environment?
• Can understanding of environmental and behavioral isotopic effects improve the power of migration studies exploiting isotopic tracers?
  

Affiliated faculty

Bowen, Cerling, Hobson, Popp, West, Wunder

Image after Norris et al., 2006, Ornitological Monographs