My friend I see occasionally out in Nob Hill alerted me to the presence of this tiny bird. I have some other shots of it here, but this is the only time I've seen one revealing his "ruby." It seems they conceal it except for special occasions.
birdwildlifenaturebird photographywildlife photographytexas birdspasserinesongbirdkingletrubycrowned kingletRegulus calendula
From Just for the Birds