Patterns of Behavior in Three Forms of the Fringe-Toed Lizards (Uma-Iguanidae)

A mixed group of 34 fringe-toed lizards (Uma) representing three races (notata notata, n. inornata, and scoparia) were observed in a large outdoor enclosure. The species-specific display patterns for the three races were similar in their elaborate posturing. A challenging Uma orients laterally towards its opponent, compresses the trunk in an asymmetrical manner (shifts the abdominal area towards the side of the opponent), extends the dewlap, and tilts towards the opponent. The push-up movements which are performed from this posture vary among the three forms. The sequence of unit movements are very similar in U. n. notata and U. n. inornata, the latter showing greater variability in pattern and cadence. The sequence of U. scoparia is distinct from those of the other two in pattern and cadence. U. scoparia and U. n. notata have a ventrolateral blotch which is absent on U. n. inornata. Dominant males displayed most frequently and performed more aggressively. Such actions resulted in a loose hierarchy of both interspecific and intraspecific dominance and subordination within the group. Dominance shifts could be affected by removal of the dominant. Courtship gestures in the form of rapid head nodding are accompanied by rapid, alternate, up and down waving of the front legs and feet. These lizards are omnivorous.