I just spent last few months trailing Turkey Vultures, looking for an elusive Black Vulture newcomer and writing about the topic (See SB Independent online Goleta Grapevine Column).
During the process, I came across several interesting references (shown below). Many websites list fascinating facts. However, in some cases I had a hard time tracking down all the primary literature that backed them.
One specific reference is to a 1964 ethyl mercaptan sensitivity study which indicates (apparently, as I didn't get my hands on the actual report) that the substance was added to gas as a means to detect leaks via the use of Turkey Vulture aggregation. However, I'm intrigued by the Smith and Paselk 1986 article whose data seems to contradict the idea that ethyl mercaptan is an attractant (or perhaps their olfactory indicator of altered heart rate is not valid) as well as the seeming lack of related reports.
Other attempts to fact find--how much a Turkey Vulture in the wild consumes in a day, for example--seemed an impossible task. In the 70's it was determined that captive Turkey Vultures eat 140 g per day. Since then much data has been collected in terms of what kind of animals are consumed but quantities apparently prove difficult to determine.
Websites
Rare Black Vulture sighting
Turkey Vulture Society
Stanfordbird Diet and Nutrition
Orange County Project to track Turkey Vultures
Primary Literature References:
Evans, B.A. and Sordahl, T.A. (2009), Factors influencing perch selection by communally roosting Turkey Vultures. Journal of Field Ornithology, 80: 364-372.
Prather, I.D., Connor, R.N., Adkisson, C.S., Unusually Large Vulture Roost in Virginia. The Wilson Bulletin, Vol 88, No. 4: 667-888.
Smith, S.A. and Paselk, R.A. (1986) Olfaction in the Turkey Vulture. The Auk, 103: 586-592.
Review Article:
DeBose, J.L and Nevitt, G.A (2008), The use of Odors at Different Spatial Scales: Comparing Birds with Fish. Journal of Chemical Ecology, 34: 867-881
