Use of Habitat by the Semiaquatic Lizard, Norops aquaticus

We assessed use of habitat by the semiaquatic lizard Norops aquaticus along the Río Java at the Las Cruces Biological Station, Costa Rica. We surveyed the river for lizards and determined characteristics of their perches relative to edge of the water. Individuals preferentially positioned themselves near eddies. Demographic classes differed in height of perches above the river, with adult males using the highest perches. Males were most likely to perch directly above water. In addition, males and juveniles tended to be in exposed areas, whereas females selected cover. Behavior of N. aquaticus on land is dependent on characteristics of rivers.