Mousebirds belong to their own Family; Coliidae. They are not related to psittacines. At one time it was thought they were related to touracos, but mtDNA analysis has disproved this. Fossils of prehistoric mousebirds have been found in Germany dating back over 20 million years ago of their ancestors known as Sandcolius. Now they are only found in Africa. A good book to read regarding the natural history and aviculture of mousebirds is "Mousebirds In Aviculture" by Kateri Davis. She is one of the few bird breeders in the U.S. that took a personal interest in this family. An ornithology text put out by Cornell University's Ornithology Lab also has an extensive description of mousebirds. I have put together my own personal library at home; downloading individual papers on recent mousebird research; everything from leg muscle tissue
analysis to thermoregulation behaviours and metabolism. Mousebirds can raise and lower their crests in similar fashion as cardinals. I'll see if I can get a digital version of the article I wrote on mousebirds . Right now I only have a hard copy. I accidentally discarded the email I sent to the bulletin editor where the text originated. Mousebirds generally pick up a food morsel in their beaks and then hold it in their foot if they choose to eat that way. They do not pick up food directly with their feet. But they do use their feet to fight amongst themselves as defense.