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Survey Instructions

Nightjar surveys are standardized population counts conducted along roadside census routes at night.  A route only needs surveyed one time per year, but during a very specific time window (see "Seasonal and Daily Timing" below) and conditions (see "Survey Conditions"). Surveys should not take much more than one hour to complete.  The only experience necessary is a familiarity with each nightjar’s characteristic vocalizations.

 

Please read all of the instructions carefully. Your commitment to following these instructions will ensure that data is collected in a standardized format so it may be comparable between all routes in the Nightjar Survey Network and our partner efforts.

2025 Survey Window Maps

Survey windows are updated each year to coincide with optimum lunar conditions. Click through to see the appropriate window(s) for your route. 

Conducting Surveys

 

Seasonal and Daily Timing

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1.) Begin each survey at least 30 minutes after sunset and end no later than 15 minutes before sunrise.

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2.) Surveys must only be conducted during these 2025 survey dates:

  • Window 1: FL, TX, and low elevation AZ* and NM: 4 Apr – 20 Apr

  • Window 2: Southern US (MO and all areas south): 4 May – 20 May

  • Window 3: Any location in the country: 2 Jun – 18 Jun

  • Window 4: Areas north of AZ, FL, NM, and TX, high elevation areas in northern US: 2 Jul – 17 Jul

  • Window 5: WA, OR, ID, MT, WY, Dakotas, MN: 1 Aug – 16 Aug​

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Contact us if you have a question about how these dates apply to your route. These dates are specifically chosen to coincide with the nights of brightest moonlight and greatest nightjar calling frequency. These are important dates to use so survey conditions are standardized across all regions of the NSN. 

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3.) Surveys must only be conducted when the moon is above the horizon and not obscured by clouds. It is a little known fact that nightjars call less frequently when the moon is still below the horizon or hidden by dense cloud cover. Check your local times for moonrise at the US Naval Observatory or local newspaper  Please note that the moon rises later each successive date.  The moon may not rise on later dates of each cycle until after 11:00pm so consider the date you choose to be completed when the moon is above the horizon.

 

EACH SURVEY ROUTE ONLY NEEDS SURVEYED ONE TIME PER YEAR

 

Route Logistics: 

 

Each survey route consists of 10 to 12 stops.  The starting point of your route will be named stop 1. All other stops are sequentially numbered and spaced 1 mile apart along the route. You may vary the exact distance up to 2 tenths of a mile between stopping points to find a safe place to park.  It is better to add space between points rather than shortening this distance to avoid counting the same individual birds twice.  Not all of your stopping points need to be on the same road. Turning onto different roads may be expected. We recommend scouting your route during daylight to become familiar with the stops and ensuring you are able to pull over safely. Your safety is paramount. If you do not feel safe at a particular stop, skip the stop and proceed to the next stop.

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Conducting Nightjar Surveys:

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Survey data can be recorded and reported in two way: 

  1. You can record and submit your results in the field using a smartphone and the NatureCounts mobile app.  

  2. OR, you can record your observations on a physical data sheet and enter your results on the NatureCounts website

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State: Record the state where your survey was conducted.

Observer and Observer Email: Record your name and email address.

Route: Record route name here.
Date:  Indicate the date of the survey. 

Start Time: Indicate the time at which you began your survey efforts.

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Survey Conditions:

 

Wind: Beaufort scale (0-4) and direction. DO NOT conduct surveys during high winds (>18 mph). High winds diminish your ability to hear nightjar vocalizations.

0 = Calm (0-1 mph), Smoke rises vertically

1 = Light (1-3 mph), Direction of wind shown by smoke drift, but not by wind vanes.

2 = Light Breeze (4-7 mph), Leaves rustle; ordinary vanes moved by wind.

3 = Gentle Breeze (8-12 mph), Leaves and small twigs in constant motion; wind extends light flag.

4 = Moderate Breeze (13-18 mph), Raises dust and loose paper; small branches are moved.

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Sky:  Quantify the percent of cloud cover. DO NOT begin a survey if the sky is completely overcast, during heavy fog, or persistent rain or snow. All of these conditions will diminish calling rates of nightjars and hamper your survey. 

0 = 0%. Clear, cloudless sky, can see stars and moon clearly. 

1 = 10% cloud cover.

2 = 20% cloud cover.

3 = 30% cloud cover.

4 = 40% cloud cover.

5 = 50% cloud cover.

6 = 60% cloud cover.

7 = 70% cloud cover. Conduct survey only if lunar illumination is not impacted by clouds. 

8 = 80% cloud cover. Conduct survey only if lunar illumination is not impacted by clouds. 

9 = 90% cloud cover. Conduct survey only if lunar illumination is not impacted by clouds. 

10 = 100%. Overcast, dense cloud cover, entire sky covered.  Do not conduct survey. 

11 = 100%*. Fog, visibility and illumination very poor.  Do not conduct survey. 

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Background Noise: Codes indicate the level that background noise impairs your ability to hear nightjars.

0 = None: Relatively quiet, little interference.

1 = Moderate: Some interference with listening.

2 = High: Substantial interference with listening.

3 = Excessive: Extreme interference with listening.

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Moon Visible (Y or N): Enter Y for YES or N for NO to indicate if the moon can be seen above the horizon while counting nightjars at the stop. This is particularly important to register when in deep valleys because the moon may be obstructed by mountain ridges. 

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Vehicle Count: Indicate the number of vehicles that passed during the duration of the survey effort at each stop.

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Air temperature: Indicate the air temperature (in Celsius) at each stop location.

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Counting Nightjars:

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At each point, count all Nightjars seen or heard for a period of SIXMINUTES. Do not include nightjars you see or hear anytime before or after the six minute counting period. Counting nightjars and recording data should be done from a stationary position outside of your automobile. Most importantly, be consistent. Use the same technique at each stop including how you focus your listening for nearby birds and distant birds.

The counting period is broken into six 1-minute listening periods on the data sheet. Record the detection history of each individual Nightjar seen or heard from the time of their first detection through their last detection in the appropriate 1-minute block of the Count Sheet.

 

Detection: Indicate how each individual is detected in each listening period: W - Wing Boom (Common Nighthawk only), C - Call, V - Visual, or N - Not Detected.

 

Distance ("Dist") and Direction ("Dir."): Provide an estimate of distance (0-100m or 100m+) along with your best estimate of the direction of each bird.

 

Repeat? ("Rep.?"): Birds will sometimes move during the counting period. Use your best judgment in determining new detections from those of birds that have simply moved during the count and aim to record each new individual on a separate line. Indicate (Y) if you when you believe an individual bird is a repeat from another stop when necessary.

 

DO NOT use whistles, audio-calls, or any method of that coaxes birds to call or come closer to you. Also, DO NOT use a flashlight to search for reflections of Nightjars eyes. These practices will bias your survey and make it difficult to compare your data to other routes. Record birds as you hear them, rather than waiting for the end of the six minute period to avoid data omission errors.

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To save time and space, consider using the following abbreviations for each species on your data sheet:

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ANNI = Antillean Nighthawk

BCNI = Buff-collared Nightjar

CONI = Common Nighthawk

COPA = Common Pauraque

COPO = Common Poorwill

CWWI = Chuck-will's-widow

LENI = Lesser Nighthawk

EWPW = Eastern Whip-poor-will

MWPW = Mexican Whip-poor-will​

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Please remember that surveys should be conducted during the allotted survey windows and daily timeframe described above (see "Seasonal and Daily Timing").  Always remember the moon should be above the horizon. Surveys should not be conducted under overcast skies, during strong wind, or when there is persistent rain or snow. If conditions deteriorate after a route is started for more than 3 stopping points, we advise you to abort the survey and attempt it on another night with better conditions.  â€‹

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Do you want to share your nightjar observations from outside of the survey effort? View the "Report Nightjar Sightings" section on our Participate page for guidance on sharing your incidental nightjar observations. 

Questions? Contact us.

Thanks for submitting!

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The Nightjar Survey Network is coordinated by the Maine Natural History Observatory and Birds Canada as part of the North American Nightjar Survey.

© 2025 by Nightjar Survey Network. 

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