Even small birds fly high

Even small birds fly high

Dr. Catherine Ivy (Assistant Professor, University of Saskatchewan, Canada), shared research this morning at the 2025 APS Summit on the remarkable hypoxia tolerance of birds. Although bar-headed geese (above) are the poster-birds for research on extreme hypoxia tolerance, I was surprised to learn that even many small migratory species of birds fly at relatively high altitude. Tiny migratory yellow-rumped warblers (~12g), for example, travel for …