2016/08/13 by Lorian Cobra Straker, Joseph R. Jehl · 1 citation
Environmental Science · Immunology and Microbiology · Agricultural and Biological Sciences · #Avian ecology and behavior #Bird parasitology and diseases #Animal Behavior and Reproduction
paper · doi:10.1111/jav.01007
openalex publication_date 2016/08/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/23
Eared grebes Podiceps nigricollis , like shorebirds and other long‐distance migrants, lay down large amounts of fat to power their journeys. To investigate the pattern of how fat and soft tissue might be mobilized, we used grebes killed in migration and applied computed tomography to reconstruct how stores in the chest, thorax, and abdomen were reduced as body weight decreased. Fat and soft tissue were each mobilized at a constant rate through the entire migration. Fat stores in birds embarking on migration were greater in the abdomen than thorax than chest. In contrast to previous studies indicating that abdominal fat was mobilized first, we found that fat from all areas was mobilized concurrently, but that abdominal fat was catabolized at a greater rate. We suggest why this pattern might be advantageous, consider whether inter‐depot differences in fat composition might be involved, and note possible energetic consequences. Whether our findings pertain to other obese or long distance migrants remains to be determined.