Dr. Mark Willis

Dr. Willis and a moth

Dr. Mark Willis, Associate Professor of the Department of Biology, and his research assistant, Andrew Finnell, studied the olfactory orientation of turkey vulture populations at the farm during the summer. Previous studies have documented olfactory orientation in the turkey vulture (Cathartes aura), but all records of behavior are anecdotal or descriptive in nature.

The goal of their study was to characterize and quantify this behavior. Willis had studied similar odor-tracking behaviors in the moth Manduca sexta and the cockroach Periplaneta americana. One long-term goal of their study was to compare the behavior of the insects to that of the turkey vultures. Farm sites used for this study included a central site located on an exposed ridge by the research ponds with supplemental sites both upwind and downwind, based on predominant northwesterly wind currents. Several methods were used to characterize flight behavior and to distinguish between odor-guided flight and other in-flight behaviors. A rough trajectory of the birds' flight were hand-sketched onto a map of the immediate area to get an overhead view of the orientation behavior. The birds also were filmed with a portable video camera as they approached the source. Using Peak Motus 8.0" motion analysis software, the team was able to plot the vultures' movements and determine velocity, acceleration, and other parameters. Additional weather notes (cloud cover, visibility, etc.) also were taken on site.