Kmc, this may be the study you're referring to; Tijl cut and pasted it here recently:
Originally Posted by Tijl
Finally, since it has been hypothesized that some animals utilize levels of UV-A as a visual cue to avoid UV-B damage, we artificially elevated ultraviolet-A levels to examine whether males exposed to artificially elevated ultraviolet-A abandoned their perches sooner compared to males exposed to visible light. We found that frogs called from perches receiving low ultraviolet-B regardless of perch height, and that frogs maintain their positions longer on perches receiving low ultraviolet-B compared to perches receiving even slightly higher ultraviolet-B levels. Exposing the frogs to artificially elevated levels of ultraviolet-A radiation caused males to move off of their perches faster than when they were exposed to a control light source. These experiments suggest that ultraviolet radiation plays an important role in frog behavior related to perch selection, even in rainforests where much of the solar radiation is shielded by the forest canopy."
@Tijl, the link to this study you provided is dead. Can you hunt up a citation or a stable URL for this, please?
So the upshot to this seems to be that a lamp that provides high amounts of UVA can trick the frog into avoiding that light since the frog uses UVA exposure as a proxy for measuring UVB exposure.