Pennsylvania Game News - July 2017 - 27
calling. The whip is sharp, the poor falls
away, and the will is the highest note.
The amorous bachelors call mainly at
dusk and dawn to attract females.
In Pennsylvania, whip-poor-wills start
calling in late April or early May, when
migrating males arrive from the southeastern United States, Mexico and Central
America. The calling continues through
June and fades away in July.
Eastern whip-poor-wills require large
tracts of forests with sparse understory
and inhabit deciduous and mixed deciduous-coniferous stands with scattered open
areas for foraging. They prefer young
forests with clearings and also are found
in the scrub oak barrens of the Poconos.
Their courtship display is rarely seen,
but has been documented. The male quietly approaches the female on the ground
while circling her and purring as she bobs
It is believed that the reproductive
behavior of whip-poor-wills correlates
with the lunar cycle.
Males sing longer on moonlit nights,
and hatching usually occurs when the
moon is waxing so that the increased
light makes foraging easier for the adults,
which must now feed nestlings, as well as
The female lays one to two eggs
directly on the ground in dry open
woods. The cream-colored eggs
have brown spots and are
flaged in pine needles or leaf litter. The
female incubates the eggs during the day,
and both parents share incubation duties
The eggs hatch in 19 to 21 days. The
hatchlings are covered in down and soon
capable of short-distance movements to
help them elude predators. The chicks are
fed a steady diet of regurgitated insects
until they fledge at around 21 days.
In recent years, conservationists and
the general public have come to share a
general sense that populations of nightjars have been declining. However, there
was no empirical data to help describe
the changes or to help plot a strategy to
reverse population losses.
In 2007, the Center for Conservation
Biology - a cooperative of the College of
William and Mary and Virginia Commonwealth University - formed the National
Nightjar Survey to collect current nightjar
distribution and population data.
The Pennsylvania Game Commission
is a partner in this effort.
Volunteers conduct standardized roadside counts on scheduled moonlit nights,
by driving and stopping at 10 points along
a predetermined route.
At each point, observers count nightjars seen or heard during a six-minute
Gathering this information over time
will point to changes in nightjar distribution and population size while experts