They look cute ^^
I have no doubt that UVA/UVB has positive effects, at least on some birds. But used wrong, it can have negative effects as well. I read some articles about it a while back, and wrote a summary for myself. I just re-read that summary and will post a few bullet points:
Birds are, unlike humans, able to see UVA light. This means that they might be able to see more colors than humans, if supplied with this light. Might not seem all that important, but for some species it seems to have an impact when it comes to breeding - perhaps their partners look more attractive in UV-light. Quail don't seem to have issues breeding in captivity though, so UVA is hardly necessary for them.
UVB on the other hand, enables the birds to produce vitamin D3. They need this vitamin, but it is possible to supply it through their feed, so strictly speaking they don't need UVB either. And it is very hard to get a bulb that is effective at producing UVB - the birds pretty much need to be within 4 inches of the bulb to get the UVB effect. And as it isn't recommended to place the bulbs closer to the birds than 1½ feet or so (if placed too close to the bird, it might cause feather picking and reduced immune response), they are very unlikely to get much UVB. Also, most bulbs hardly produce any UVB at all once they have been used for about 6 months.
UV light is hard on bacteria so it might make the cage more sanitary - but it also causes several vitamins(A, C and E) in the feed to break down very quickly.
The human eye is very sensitive to UV-light, but birds use vitamin A to filter it out. If the diet has too little vitamin A, the light might cause eye damage.
Wrongly balanced UV-lights (like those intended for reptiles) might cause tumors and cannibalism in birds.
There were a few more points in the articles, but those were the major ones related to the actual UV light. My conclusion this far has been 'It might be nice to have, but unless you have a feather picking parrot or a pair of rare birds that just won't breed, don't bother - and don't expect it to supply your birds with D3'.