For those of you not familiar with it, the Virginia Museum of Natural History still has some copies of the "Identification of Waterfowl Breastbones and Avian Osteology (Sterna) of North American Anseriformes" available. I have copied the publication information and the link to purchase below. It is not available as a pdf. Elizabeth Moore Identification of Waterfowl Breastbones and Avian Osteology (Sterna) of North American Anseriformes <http://www.vmnh.net/store.cfm?itemID=15> Special Publication #10 By David W. Oates, Ed D. Boyd, and Jennifer S. Ramaekers <http://www.vmnh.net/store.cfm?itemID=15> $10.00 ISBN-1-884549-16-0 Softcover 55 pages 20 line drawings 10 black and white images 19 tables Morphological features of duck breastbones provide a means for identification to genus, and certain measurements and observations may allow for further identification to the species level. In an attempt to identify duck breastbones, observations were made on over 2,300 specimens, of which 1,350 were actually measured and morphological characteristics tables created (Appendix). To assist field and museum personnel, a dichotomus key, along with an identification table, were prepared (Figure 11). http://www.vmnh.net/index.cfm/topic/publications