Hi! I was recommended to your site last year and have been an avid whatbird user ever since. Just now started posting to the forums and put up some pics of birds you helped me greatly in ID'ing.
I did want to ask, though, as an amateur, I am learning the markings I need to look for, when trying to ID a bird. That narrows down my search alot, but the icons do not show (or maybe I need my eyes checked) very well, some of the more detail markings you can't see in a small icon. I have to go into each page, and, once opened, go "No, that's not it, It has one wing bar, I'm looking for two." or "No, bill color is wrong." I think the search time would be greatly reduced, and a correct ID made more easily, if users were able to add to the search request for one wing bar, or say a dark bill instead of yellow. Instead of having to look through say 20 birds or so, where ten don't have one wing bar and a dark bill. (Or maybe I'm searching wrong.)
I understand in juveniles this can change, but the search engine seems to rely mostly on adult markings, correct?
Is there a way, or is it a good idea, to have a functon, much as you have for head markings/patterns, where the areas searched must match and then a selection for white wing bars, such as a multiple choice between one, two or none? That would narrow my search down.
Also, some birds while having the same shape bill, have different colors. Can a bill color be added, to help in searching for an ID as well? i.e. yellow bill, top black/bottom yellow, pink bill, etc. with the check boxes like you do for shape. You do also mention legs and feet color, in the description, but since I am looking at their bill shape to begin with, I see their bill color as well and might not notice their legs or feet color before they fly off. The head is what I look at first. The sparrows I see all have cone shaped bills, but the coloring is different on many.
Again, I know juveniles might mess up the search, if I'm looking at one, so I don't know if those two ideas might fly. (Pardon the pun.)
I apologize if I my question is not clear. It is a late hour I am asking this.
Thanks for such a great site. It has enhanced my birding experience greatly and given me alot of info, also to help others, who know my new found interest, and they too, ask me "What bird?" and I say yes, go to their site, you'll find out! 
Wishing you much sucess in the future.
