Aroma-dillo or Area-dillo? An examination of armadillos' sensory modality bias

Many species of armadillo demonstrate impressive navigation abilities and may compensate for poor eyesight with a strong sense of smell. We examined which modality four three-banded armadillos and one hairy armadillo prioritized when two cues (olfactory or spatial) previously associated with reward were put in conflict. The armadillos learned to approach one of two locations - each paired with a distinctive scent - for reward. When the scent cues were reversed, the armadillos demonstrated a strong bias for attending to the location cue over the scent cue. Therefore, a follow-up test presented them with the same scents and assessed their spontaneous preferences. Although the armadillos did not show an immediate preference for the previously rewarded scent, they did learn to discriminate two novel scents when they were placed in a circular arena containing two tins - each scented with a unique scent. They learned to selectively open the tins containing reward based on scent. This result indicates that their bias towards location cues was not due to an inability to discriminate between scents. Armadillos may attend to either location or scent but may prioritize location when both cues are equally predictive.