The “Secret” in Secretions: Methodological Considerations in Deciphering Primate Olfactory Communication

Abstract

Olfactory communication in primates is gaining recognition; however, studies on the production and perception of primate scent signals are still scant. In general, there are five tasks to be accomplished when deciphering the chemical signals contained in excretions and secretions: (1) obtaining the appropriate samples; (2) extracting the target organic compounds from the biological matrix; (3) separating the extracted compounds from one another (by gas chromatography, GC or liquid chromatography, LC); (4) identifying the compounds (by mass spectrometry, MS and associated procedures); and (5) revealing biologically meaningful patterns in the data. Ultimately, because some of the compounds identified in odorants may not be relevant, associated steps in understanding signal function involve verifying the perception or biological activity of putative semiochemicals via (6) behavioral bioassays or (7) receptor response studies. This review will focus on the chemical analyses and behavioral bioassays of volatile, primate scent signals. Throughout, we highlight the potential pitfalls of working with highly complex, chemical matrices and suggest ways for minimizing problems. A recurring theme in this review is that multiple approaches and instrumentation are required to characterize the full range of information contained in the complex mixtures that typify primate or, indeed, many vertebrate olfactory cues. Only by integrating studies of signal production with those verifying signal perception will we better understand the function of olfactory communication.

Social odours covary with bacterial community in the anal secretions of wild meerkats

“…Also, because we could not control for the amount of secretion collected, regardless of sampling method, we did not rely on the absolute abundance of chromatogram peaks; rather, we quantified each peak as the proportion of the peak size relative to the total area of the chromatogram 67 . For odorant samples obtained from the anal pouch, we first verified that repeat samples from the same individual produced consistent chromatograms (see Fig.…”

Proteins and peptides as pheromone signals and chemical signatures

“…Beynon et al (2013) and Drea et al (2013) discuss techniques for proteomic analysis of mammalian scent marks and secretions; their observations may be relevant to studies of other taxa.…”

Socioecological and phylogenetic patterns in the chemical signals of strepsirrhine primates

“…Comparative studies can 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 be methodologically challenging (delBarco-Trillo, Burkert, Goodwin, & Drea, 2011;Drea et al, 2013), but can provide a wealth of information about species differences relevant to understanding broader socioecological patterns, as well as unique insights into the evolution of chemical signals across different phylogenetic scales (Symonds & Elgar, 2008). Here, we review recent comparative studies on the volatile composition of chemical signals in strepsirrhine primates to elucidate whether socioecological factors correlate with the composition of chemical signals and to uncover the mode and speed of chemical signal evolution.…”