Bruce Cousens of Victoria mentioned a couple of weeks ago that most martins
there had fledged and become elusive for observers.
After fledging they may stick around to roost for up to a couple of weeks,
learning to feed on the wing. I've seen the adults fly high carrying
dragonflies, with the entire brood in hungry pursuit. Initially they feed
the young directly, and later will drop prey for the young to catch. They
may be hard to find by day, but show up at dusk. Often it's easier to find
them by ear than by sight; they can be quite high in a kettle, and will then
suddenly drop out of the sky.
Martin fledglings may also roost in different housing from which they were
born; I've seen gourds that had been empty all season suddenly have 4-6
martins in the evenings. Some years in the Seattle area I've seen martins
near their nest sites as late as mid September. It appears that they may be
leaving earlier this year.

Kevin Li
Ballard, USA