Below a few web sites and academic papers about ornithologists.
On the web
Joseph Grinnell: wikipedia;
David Lack: wikipedia
Konrad Lorenz: wikipedia
Niko Tinbergen: wikipedia
Roger Tory Peterson: wikipedia
Academic papers
Gill FB (1994). Ernst Mayr, the Ornithologist. Evolution. 48:12–18.
Steinheimer FD (2004). Charles Darwin’s bird collection and ornithological knowledge during the voyage of H.M.S. Beagle, 1831–1836. Journal of Ornithology 145:300–320.