Yes you are partly correct. I read in many resources on captive amphibians specifically Hyla Versacolor (Eastern Grey Tree Frogs ) in captivity do not require AS MUCH UV RAYS because as you said they are in semi shade arboreal environment. HOWEVER you are WRONG they must have SOME UVB rays esp. indoor captivity…. PERIOD. I' m using scientific facts in direct resources regarding CAPTIVE FROGS .. Please look up the death rate prior to the discovery by zookeepers world wide that lack of proper UVB RAYS esp. was killing off exhibits of captive reptiles and AMPHIBIANS. FROGS are AMPHIBIANS!!! DON'T GUESS DO YOU RESEARCH !!!!! In fact it is not advised to give these frogs VIT D3 as a supplement as they do not utilize it unless produced by UVB exposure. When I find that exact resources again, I will put it on a post for all to see!!!!!!. I'm not getting paid to write my thesis paper on public forum. SCIENTIFIC SKEPTICS DRIVE ME NUTS!!!! It was advised to use calcium powder w/out D3 in FACT!!! ALERT!!!! WOULD THE RETIRED BRONX ZOO HERPITOLOGIST PLEASE CHERP IN AND HELP ME WITH ALL THESE SKEPTICS ON VITAMIN D3 IN CAPTIVE AMPHIBIANS…. THANKYOU DR.??? You are on this frog forum somewhere. I just can' figure out how to look up previous posts????????????????