Center for Conservation Biology | Nightjar Survey Protocols and Instructions

Nightjar Surveys are standardized population counts conducted along roadside census routes at night. Each route is surveyed only one time per year but must be conducted during a very specific survey time window. A survey will only take a little over an hour to complete. However, since surveys are only collected once per year, it takes many years of data from a route before they provide reliable information on population trends.

There are two survey windows for 2009. A survey route only needs to be conducted one time during either one of these two time frames depending on geography;

Window 1: May 31 through June 15, 2009

Window 2: June 29 through July 15, 2009 (Northern States Only)

These dates are specifically chosen to coincide with the the period of brightest moonlight and greatest Nightjar vocal activity. Nightjars call more frequently and more consistently during bright moonlit nights. As a result, surveys conducted during this time will yield more accurate and more reliable population estimates. A route only has to be surveyed one time per year.

To read a publication on the implications of moonlight on detection rates and long-term monitoring programs click here.

There are four additional considerations for choosing a night to conduct surveys;

1) Moonrise - Conduct surveys only when the moon is above the horizon. It is a little known fact that Nightjars call less frequently at night when the moon is still below the horizon, even when a full moon is anticipated. Check your local moonrise forecast or visit the US Naval Observatory Website for moonrise times at your specific location. This link takes you directly to the moonrise/moon set calculator. In general, the moon rises during daylight on May 12 and sets a little after midnight (1:44am). Surveys should be conducted before moonset. However, on May 20 the moon does not rise until after dark (9:00pm) and rises later each night. Surveys should only be conducted after moon rise. During the second survey window, the moon begins to rise after dark on June 17. Please consider these times when planning surveys so the best moon conditions can be chosen. Special consideration may also need to be undertaken in mountainous areas, where the time that the moon rises above horizon may be delayed from standard times.

2) Nightfall - Surveys should begin 30 minutes after sunset, or later if the moon is still below the horizon and should be finished 15 minutes before sunrise or before the moon is below the horizon.

3) Cloud Cover - Nightjars also call less frequently on nights when the moonlight is obstructed by dense cloud cover. Avoid overcast nights even if under a full moon.

4) Rain and wind- Surveys should not be conducted if winds are > 15mph or during persistent rain. These conditions will hamper your ability to hear Nightjars consistently.

Each survey route consists of 10 roadside stops spaced 1-mile apart. (Note: current USGS Breeding Bird Survey Routes are placed 0.5 miles apart). The starting point of your route should be named stop #1 and the remaining sequentially numbered from 2 through 10. You may need to vary the exact distance between stops to find a safe place to park. It is better to increase the distance between stops for this instance rather than shortening this distance to ensure that you do not count the same birds at two stops.

See a list and maps of routes in your state or learn more about creating your own route by clicking here.

Please note: we show 10-mile segments only as a guide on our maps section- however, your route will only be approximately 9 miles with some slight variation due to spacing needs between individual points.

Conducting the Survey:

At each stopping point, count the numbers of Nightjars heard or seen for a period of SIX MINUTES. Nightjar surveys should be conducted from a stationary position outside your automobile. Do not include Nightjars seen or heard either before or after the six-minute counting period.

DO NOT use whistles, audio CDs or tapes, or any method that coaxes a Nightjar to call or move closer to you. Also, DO NOT use a flashlight to scan for reflections of Nightjars eyes or other identification.

The counting period of each stop is broken into six 1-minute blocks so your data can be compared to studies using shorter time periods. Please read all instructions on the United States Nightjar Survey Instructions and Data Sheet (see below) for these details and more.

Instructions and Data Sheet:

We have developed a standardized data sheet to maintain consistent reporting among all volunteer observers. Please read all instructions on collecting and recording data one of the Instructions and Data Sheet file types;

Download Microsoft Word version of the Instructions and Data Sheet

Download Adobe .PDF version of the Instructions and Data Sheet (requires free Adobe Reader - download here.)

In and effort to save preparation and mailing costs, we ask you to download the instruciton sheets and view the location of the routes on-line. We will not be sending information packets to volunteers unless you are unable to download the information from the web.

Mapping your Nightjar Survey Stops:

Documenting the exact position of your Nightjar survey stops is important for data analysis and archival. Even if you have adopted an existing route, the geographic placement of your stops should be mapped or collected using a Global Positioning System (GPS) device. We provide various methods to document stop locations. See how to create map data using Google Maps or Google Earth, collect GPS data , or provide hardcopy data maps by clicking here.

Submitting Data:

Submitting data in a timely fashion will further the success of this program. Follow a link to Submitting Nightjar Survey data here.