Effects of ultraviolet radiation on locomotion and orientation in roughskin newts (Taricha granulosa)

Environmental changes, including those associated with the atmosphere may s ignificantly affect individual animals and ultimately populations. Ultravio let (UV) radiation, perhaps increasing due to stratospheric ozone depletion , has been linked to mortality in a number of organisms, including amphibia ns. The eggs and larvae of certain amphibian species hatch at significantly lower rates when exposed to ambient ultraviolet light. Yet little is known about the sublethal effects of UV radiation. For example, UV radiation may affect specific behaviors of an animal that could alter its ability to sur vive. To examine if UV radiation affects amphibian behavior, we used roughs kin newts (Taricha granulosa) as a model. Newts were exposed to low-level d oses of UV in the laboratory and then tested in the field to examine if UV- exposed and control (no UV) newts differed in orientation towards water or in locomotor activity levels. UV-exposed and control newts both exhibited a significant orientation towards water in field tests but there was no sign ificant difference in orientation between treatments. However, UV-exposed n ewts were significantly more active than control newts. Our results suggest that exposure to short-term low levels of UV radiation alters certain beha viors. Environmentally induced changes in behavior may have significant eco logical and evolutionary consequences.