Biomarkers for migration research
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 will support a postdoc to develop, test, and improve models that will constitute the next major advance in isotope-based tracking of animal migration; this might include models linking multiple isotope systems within individuals, improved models for environmental substrate isotope ratios, or behavioral and physiological models describing the relationship between "input" signal and "recorded" signal. A strong basis for this work exists in the many thousands of measurements that have been generated during the past ~15 years of isotope-based migration research. Efforts focused on both marine and terrestrial systems are possible.
Among the key questions to be addressed are:
- 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?
Bowen, Cerling, Hobson, Popp, West, Wunder
Image after Norris et al., 2006, Ornitological Monographs
New Instructional Video Module on Biogeography and Isotope Fractionation in C3 & C4 plants with Christopher Still! Check out all of the videos at the bottom of the 'Summer Courses' tab!
New Publications - Two new papers by SPATIAL alum Sean Brennan involving salmon migration (here) and using dendritic network models to improve Strontium isoscapes (here)!
New Blog Post - Former SPATIAL student Katie Wedemeyer-Strombel discusses her experience as a SPATIAL student last summer! (Check it out here!)
Awards - Former ITCE post-doc Jennifer Cotton has received an NSF Macrosystems Biology Grant. Congratulations, Jen! (Check out the NEON press release here!)
New Publications - Former SPATIAL student Chabi Djagoun's work on carbon isotope niches in herbivores in a west African savannah is now available in Mammalian Biology - Free download until Nov 7th! (Check it out here)
New Publications - Former SPATIAL student Giovanny Mosquera in two new publications involving high elevation tropical ecosystems (Hydrological Processes and Hydrology and Earth System Sciences)
Awards - Congratulations to Jim Ehleringer for receiving the prestigious Rosenblatt Prize for Excellenc! (Read more here.)
Presentations - Several SPATIAL & IsoCamp instructors and past students represented at the 10th annual (ISOECOL meeting in Tokyo!) last week.
IsoMAP is a dynamic, online workspace for spatial analysis, modeling and prediction of stable isotope ratio variation in the natural environment. The initial realease of the IsoMAP gateway is now live and supports precipitation isotope ratio modeling. Visit IsoMAP to learn more or to start making isoscapes today!