I've got house wrens nesting in a bluebird box (although there are two
empty and quite beautiful wren houses nearby). For three days now, the male has
stood on the top of the box, singing, from a little after 5AM until after
6PM. I think he stopped for an hour or two one day at the hottest part of
the afternoon, and I'm assuming he has taken a break during downpours. (I
couldn't have heard him then anyway.) I've found myself timing him. He almost
always pauses only 4 to 5 seconds between his liquid warbles! Every so often
there's a 10 second gap, during which he flies to a nearby garden post and does
a few warbles there. Just like an unusually sturdy little wind-up toy, this
bird lets out apparently identical sounds, regularly, every few seconds, at
least four thousand times a day!
I assume his mate is incubating, and that I'll know exactly when the chicks
hatch because suddenly daddy will be too busy to be singing.