Olfactory function in the red kangaroos (Macropus rufus) assessed using odor-cued taste avoidance

Each of six kangaroos, tested in a seminatural environment, learned to respond readily to water and to sniff at but not ingest an aqueous solution of 0.1% isoamyl acetate plus 0.5% quinine. Avoidance of the odor stimulus typically occurred after licking at the solution on two to three trials for most subjects. Kangaroos also learned to avoid lower concentrations of isoamyl acetate and to discriminate between isoamyl acetate and ethyl acetate. These results are among the first to document olfactory function in kangaroos. The odor-cued taste-avoidance procedure provides a relatively simple test of olfaction that can be used in the field with open-range animals. (C) 1999 Elsevier Science Inc.