Nestling fledging success
Exposure to experimentally elevated traffic noise could have
affected nestling survival directly, by increasing stress, or indirectly,
through changes in parental behavior. We quantified fledging
success by tracking nestlings from hatching to fledging. We
considered a nestling to have successfully fledged if it was missing
from the nest after reaching the developmental stage where fledging
is possible (at least 7days post-hatch) (Morton, 2002). Nestlings
that were found to be dead in the nest or nestlings that were missing
from the nest less than 7days post-hatch were considered
unsuccessful at fledging. Partial nest predation is rare in this
population (Morton, 2002). Therefore, our criteria for fledging
success provide an accurate measurement of nestling survival.