Abstract Cryptochromes (CRY) are highly conserved signalling molecules that regulate circadian rhythms and are candidate radical pair based magnetoreceptors. Birds have at least four cryptochromes (CRY1a. CRY1b. CRY2. https://www.nacrack.com/mega-choice-2005-2006-NISSAN-ALTIMA-Radio-Receiver-AM-FM-stereo-single-CD-Player-G-mega-value/