Using high-resolution geospatial datasets to investigate the role of geomagnetic cues during long-distance bird migration
Abstract
The Earth’s magnetic field is an orientation and navigation cue for migratory animals, especially birds. However, current experiments used to test this hypothesis are limited. In my thesis, I compare different methods for combining animal tracking data with high-resolution satellite geomagnetic data by using an open-source software called MagGeo. I use the best-performing MagGeo algorithm to investigate if white storks Ciconia ciconia use geomagnetic cues to cross the eastern Sahara. Crossing this inhospitable and featureless habitat has likely selected for unique strategies that facilitate successful bird navigation during migration. I show that MagGeo can reliably be used to annotate animal movement tracks with geomagnetic data with high global accuracy. I find that white storks may use geomagnetic cues and prevailing wind conditions to cross a landscape barrier. Collectively, my work encourages further development, testing, and application of open-source data and tools to uncover relationships between migratory animals and geomagnetic data.