Google doesn't help much if all you know is "small brown bird". Other sites don't help much unless you were able to get a decent picture.How many times have you seen a bird and thought "I wonder what that is?"
https://wotis.it?bird works by showing you a series of thumbnails of all bird photos available on the system PLUS a series of keywords. Simply select a keyword - such as "brown" and the system will hide any thumbnails which are not tagged as being brown. Then select "small" and it'll hide anything which isn't small.
You are then left with only small brown birds to choose from - or choose more keywords to reduce the list further. Simply hover over a thumbnail to have it shown as featured.