The team collected juvenile juncos from two populations, one that resides in and around the University of California San Diego campus in La Jolla, Calif., and another that lives in the Laguna Mountains, about 42 miles east. After capture, the birds were transported to aviaries in Bloomington, Ind., and raised under identical environmental conditions. The scientists used gas chromatography-mass spectrometry to isolate 19 volatile compounds from the preen oils which are secreted from the birds' uropygial glands near the base of the tail.
The researchers confirmed that individual birds sampled over time produce levels of each of the volatile compounds that remain more or less constant. They also found gross differences between males and females, and between juncos from the UC San Diego population and birds from the mountains. These population differences were found even though the birds were raised in identical conditions, suggesting that the odors have a genetic, rather than an environmental or developmental basis.
The particular suite of 19 compounds is, as far as the scientists know, unique to juncos. However, this area of research is so new that odor chemistry profiles have been documented for only a few species. This field of research is growing rapidly as biologists realize the potential importance of scent in bird communication and evolution.
Until just a few years ago, most bird biologists believed that smell played little or no role in bird behavior. The olfactory bulb -- a portion of vertebrate brain known to interpret odors -- is small relative to birds' bra
|Contact: David Bricker|