Here is an update: The chicks are now about 2 weeks old.
blue caps in this video used an old orange cheek nest - the
orange cheeks had dismantled the top to use the nesting material
somewhere else and the blue caps decided to move in. This nest
has the most visible opening of any nest my blue caps have used
to date, and thus I was able to get the following video of the
blue caps feeding their chicks. There are three chicks in this
nest (the cock is very old and losing his fertility) and they
are 2-3 days old. The chicks are only visible as occasional
blurs of grey fuzz popping up for food from the bottom of the
the male blue cap (second half of the clip) looks odd because
a long time ago, his former mate (no longer with us) plucked
his ears and the feathers never regrew.