During my lunch break yesterday at Aberdeen Proving Ground in Harford County, I was quite surprised to find outside of my building a dependent fledgling Chipping Sparrow begging and being fed by one of its parents.  The two were on the ground, beneath some shrubbery.  A couple of hours later in the afternoon they were both in the lower limbs of a nearby oak, the youngster still incessantly giving a series of rapid chips and following the parent as it gleaned the branches for food.  The late egg date for Chippies according to the Yellow Book is Sep 2.  In trying to guess when this youngster's egg was laid, Dave Ziolkowski reports that incubation and time to fledge are both in the 10-12 day range for CHSP.  The unknown variable here is once they leave the nest, how long are these young birds dependent on the parents for food?  In any case, this seems like a very late breeding record.