title: Effects of two plant secondary metabolites, cineole and gallic acid, on nightly feeding patterns of the common brushtail possum.
abstract: We investigated effects of two plant secondary metabolites (PSMs), cineole and gallic acid, on the nightly feeding behavior of the common brushtail possum (Trichosurus vulpecula), a generalist folivore. We tested whether possums altered their feeding behavior in response to increasing levels of cineole, a dietary terpene. Possums were fed artificial diets containing three levels of cineole: zero (basal diet), medium (6.8% of total dry matter, DM), and high (15.3% DM). In another experiment, we introduced gallic acid, a dietary phenolic, into the diets. Possums were offered a Choice PSM diet (cineole and gallic acid diets simultaneously) or a No-Choice PSM diet (containing either cineole or gallic acid). Detoxification products of cineole and gallic acid were examined in urine to determine that different detoxification pathways were utilized in the elimination of each compound. With increasing cineole levels, possums ate less, had smaller feeding bouts, and had a lower rate of intake, but did not extend their total nightly feeding time. Possums offered the Choice PSM diet, compared with the No-Choice diets, ate more, had larger feeding bouts, and tended to increase their rate of intake. Results from the urinary analysis indicated that gallic acid and cineole were not involved in competing detoxification pathways in brushtail possums. There was also a significant sex effect: females ate more overall, ate more per feeding bout, and ate at a higher rate than males. These results indicate that PSMs not only constrain overall intake, but that possums alter their feeding behavior in response to them. Altered feeding patterns may reduce the negative influence of PSMs on intake.
authors.affiliation: Cooperative Research Centre for Sustainable Production Forestry, School of Zoology, University of Tasmania, GPO Box 252-05, Hobart, Tasmania 7001, Australia. wigginsn@postoffice.utas.edu.au
authors.forename: Natasha L
authors.initials: NL
authors.lastname: Wiggins
authors.forename: Clare
authors.initials: C
authors.lastname: McArthur
authors.forename: Stuart
authors.initials: S
authors.lastname: McLean
authors.forename: Rebecca
authors.initials: R
authors.lastname: Boyle
mesh_terms: D000818:Animals; D002940:Circadian Rhythm; D003511:Cyclohexanols / Q000378:metabolism / Q000494:pharmacology* / Q000652:urine; D000077591:Eucalyptol; D005247:Feeding Behavior; D005260:Female; D005707:Gallic Acid / Q000378:metabolism / Q000494:pharmacology* / Q000652:urine; D008297:Male; D039821:Monoterpenes / Q000378:metabolism / Q000494:pharmacology* / Q000652:urine; D009893:Opossums; D010945:Plants, Edible; D012737:Sex Factors
chemical_list: D003511:Cyclohexanols; D039821:Monoterpenes; D005707:Gallic Acid; D000077591:Eucalyptol