Count Nightjars By The Light Of The Moon

Common nighthawk (photo by Chuck Tague)
Common nighthawk (photo by Chuck Tague)

Next week the last survey window opens for counting nightjars by the light of the moon. It’s a fun way to go birding on a moonlit night — June 20 to July 6, 2018.

Nightjars are a worldwide family of nocturnal/crepuscular birds that eat flying insects on the wing.   They have long wings, short legs, short bills and very wide mouths. Two of these cryptically-colored species are found in Pennsylvania:

  • Common nighthawk (Chordeiles minor), in flight above, breeds in cities and open habitat, grasslands, dunes.
  • Eastern whip-poor-will (Antrostomus vociferus), roosting below, breeds in forests near open areas.
Whip-poor-will, 2014 (photo by Cris Hamilton)
Whip-poor-will, 2014 (photo by Cris Hamilton)

Both populations are in steep decline and so are other nightjars in North America. Scientists don’t know why and they need more data.  That’s where we come in.

The Center for Conservation Biology set up the Nightjar Survey Network to collect population data about these birds. Their website describes how it works:

Nightjar surveys are easy to perform and will not take more than two hours to complete. Volunteers conduct roadside counts at night, on scheduled bright moonlit nights, by driving and stopping at 10 points along a predetermined 9-mile route. At each point, the observer counts all Nightjars seen or heard during a 6-minute period.

Wait for a moonlit night, drive your route, stop and listen. Count by sound!  Click here for their voices.

Register for the Nightjar Survey Network here, then select or create your own 9-mile route. For more information see

The Nightjar Survey needs volunteers across the continent — not just in Pennsylvania.  Here are the species to count.

  • Antillean nighthawk
  • Buff-collared nightjar
  • Chuck-wills-widow (named for its call)
  • Common nighthawk (named for its behavior)
  • Common pauraque
  • Common poorwill (named for its call)
  • Lesser nighthawk
  • Eastern whip-poor-will (named for its call)
  • Mexican whip-poor-will


p.s. While you’re out there you might hear owls. 🙂

(photo credits: common nighthawk in flight by Chuck Tague; roosting whip-poor-will by Cris Hamilton)

2 thoughts on “Count Nightjars By The Light Of The Moon

  1. Could it be another case of humans using pesticides to rid flying insects that they feed on? It will be interesting to see what they discover. Thank you for highlighting this Kate.

  2. I think they are more frequently seen in urban area, because of bugs drawn to the lights. One of the negatives is that they nest on flat gravel roofs in the city. And when other materials are used for roofs – such as rolled roofing, the nesting area is gone. You’ll hear nighthawks before you see them. They call the whole time they are flying. And they’re quite high in the air – maybe 150′ or so. Lots of folks mistake them for bats or chimney swifts, but chimney swifts nest by night, and bats are much smaller and fly much lower. If you live in an urban area. open your back door at nite, during the summer, and listen. You can’t miss them Come the cooler weater, they leave to migrate to S. America.

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