What smells? Developing in-field methods to characterize the chemical composition of wild mammalian scent cues
Creator
Thompson Cynthia L; Bottenberg Kimberly N; Lantz Andrew W; de Oliveira Maria A B; Melo Leonardo C O; Vinyard Christopher J
Publisher
Ecology and Evolution
Description
Olfactory cues play an important role in mammalian biology, but have been challenging to assess in the field. Current methods pose problematic issues with sample storage and transportation, limiting our ability to connect chemical variation in scents with relevant ecological and behavioral contexts. Real-time, in-field analysis via portable gas chromatography-mass spectrometry (GC-MS) has the potential to overcome these issues, but with trade-offs of reduced sensitivity and compound mass range. We field-tested the ability of portable GC-MS to support two representative applications of chemical ecology research with a wild arboreal primate, common marmoset monkeys (Callithrix jacchus). We developed methods to (a) evaluate the chemical composition of marmoset scent marks deposited at feeding sites and (b) characterize the scent profiles of exudates eaten by marmosets. We successfully collected marmoset scent marks across several canopy heights, with the portable GC-MS detecting known components of marmoset glandular secretions and differentiating these from in-field controls. Likewise, variation in the chemical profile of scent marks demonstrated a significant correlation with marmoset feeding behavior, indicating these scents' biological relevance. The portable GC-MS also delineated species-specific olfactory signatures of exudates fed on by marmosets. Despite the trade-offs, portable GC-MS represents a viable option for characterizing olfactory compounds used by wild mammals, yielding biologically relevant data. While the decision to adopt portable GC-MS will likely depend on site- and project-specific needs, our ability to conduct two example applications under relatively challenging field conditions bodes well for the versatility of in-field GC-MS.
Subject
behavior; callithrix-jacchus; chemical ecology; ecology; fruit odor; marking; Marmoset; odor; olfactory cues; portable GC-MS; scent marking; Sex; signals; signatures
Do Common Marmosets (Callithrix jacchus) Use Scent to Communicate Information about Food Resources?
Creator
Thompson Cynthia L; Blanck Lauren M; Pearson Meghan; Scheidel Caleb; Vinyard Christopher J
Publisher
Folia primatologica; international journal of primatology
Date
2018
2018
Description
Many animals use olfactory cues to signal information about food resources; however, this particular use of scent has received little attention in primates. Common marmosets (Callithrix jacchus) are exudativores that gouge bark to elicit exudate production and frequently deposit scent marks at gouge holes. We conducted preliminary tests of the hypothesis that common marmosets use olfactory cues to communicate information about exudate value, with more desirable resources targeted for marking. We performed choice experiments on two captive male marmosets. The animals were presented with: (1) a urine scent-marked and unmarked food resource, and (2) a high and low value food resource (i.e., greater/lesser food volumes). Marmosets placed more scent marks on high, compared to low, value food resources. Animals also spent more time gouging, removed more bark and more frequently revisited high versus low value food resources. Lastly, scent-marked foods were gouged more often than unmarked foods. Our findings support the hypothesis that marmosets use scent marking and olfaction to convey information about food resources, although verification in a larger sample is needed. Nonetheless, the demonstrated link between food value and scent marking suggests that olfactory signals may aid marmoset foraging decisions.