Dear WW: In reading about hummingbirds the other day, it mentioned nestlings
early developing ability to hoist their rear end up and over the edge of nest,
relieving mothers of duty of picking up fecal pellets from nest. Amazing how
such behaviour develops.

I'm reminded of cartoon I saw many years ago, of a bird nest with three fledgelings
flitting joyously above it, with one youngster sassily informing his harassed parents
"I'm going to stay here, and be a problem child."