Here are a few examples of hummingbird research.
Prof. Don Powers has collected references for hummingbird scientific literature. Some papers are readable online in PDF format.
Hummingbird banding in East Alton, Illinois, 11/8/00
An Allen's Hummingbird arrived at my home on Thanksgiving 2008.
In July 2011 I banded a leucistic Ruby-throated Hummingbird in the Missouri Ozarks.
In August 2014 I banded an albino Ruby-throated Hummingbird in Fenton, MO.