Every spring, hummingbirds embark on an ambitious migration, flying thousands of miles from Central America and Mexico to breeding grounds in the U.S. and Canada. Hummingbirds migrate an average ...

Audubon: Climate change is shifting bird migration Southeast Arizona, important habitat, is greatly affected. By Tony Davis Arizona Daily Star Jun 10, 2009 Jun 10, 2009; 1 of 7 ...

TUCSON, Ariz.—Grazing by the livestock industry has damaged at least 57% of the critical habitat of western yellow-billed cuckoos in public grazing allotments in Arizona and New Mexico, according to a ...

Changes in the number, shape, efficiency and interconnectedness of organelles in the cells of flight muscles provide extra energy for birds’ continent-spanning feats. Weighing in at a single ounce, ...