Wood Frog Monitoring Program
Survey Instructions

This program is no longer active. Material on these pages is here only for reference.


You can do a Roadside, Backyard, and/or Incidental Survey. They all complement one another and provide valuable information to the Alaska Wood Frog Monitoring Program. For the Roadside Survey, volunteers drive on a road of their choice and mark the locations of suitable frog habitat (anywhere that has standing water). The first three to ten spots become the survey stops on the route. Volunteers then re-survey their route every few days (or even once a week) during the calling season (this lasts two to three weeks). Backyard calling surveys monitor one convenient site daily during the calling season (or as close to daily as you can manage). The surveys gather information on the dates frogs begin to call, the duration of the breeding season, patterns of calling throughout the day and the breeding season, and changes in the population over time. To supplement our Roadside and Backyard Surveys we would like any Incidental observations of amphibians wherever and whenever you happen upon them. Every sighting adds a piece to the puzzle and it would be appreciated if you take the time to record the details of your chance amphibian encounters as well.

Site Selection

Roadside: Volunteers should select a route with at least three sites (up to ten) of potential frog habitat in their survey area. Only routes with 10 sites can be included in the international dataset for the North American Amphibian Monitoring Program. Virtually anywhere that has standing water for at least part of the summer qualifies as potential frog habitat. This includes ponds, bogs, marshes, temporary pools, or roadside ditches. Frogs can potentially breed anywhere there is standing water, so do not reject potential breeding sites because they do not fit the image of an ideal frog pond. Furthermore, sites should not be selected based on whether frogs are present or not. Where frogs are not found is as useful information as where frogs are. Sites must be a least ½ mile apart. This ensures that you do not hear overlapping calls from two listening posts. Sites should be easily accessible at night – roadside sites are encouraged. Avoid sites that require trespass on private lands or are difficult or time consuming to access.

Backyard: Volunteers should select a site that they know frogs inhabit – preferably in or near your own backyard. The site should be easily accessible–backyard and roadside sites are encouraged. Avoid sites that require trespass on private lands or are difficult or time consuming to access. Decide on the exact spot at the site you will be listening from – we ask that you listen from the same listening post each day you run the survey. Marking your listening post with sticks, stones, or survey tape may be helpful.

Surveying the Site or the Route

You may choose to survey and monitor one site only, or you may select a number of sites and combine them into a monitoring route. The choice is yours, but if you elect to monitor a route, please try to visit all sites along the route on the same day.


Wood frogs are expected to emerge from hibernation sometime in late April or early May, depending on temperature and snow cover. More southerly areas may start hearing frogs around the last week in April; Sites further north, such as Talkeetna, will probably not hear frogs calling until mid-May. But you never know!!! For best results, start visiting your site(s) daily before you hear the first frog calls and continue until the frogs are no longer calling. It is estimated that this will be a two to three week period. Don’t worry if you miss a few nights - Collect information for as many nights as you can.


You may conduct your surveys anytime between Noon and two hours after dusk, but please try to do your surveys at the same time every day. Whenever you survey, be sure to document the time you surveyed on the datasheet. This is very important! We must know what time of day the surveys were run in order to detect differences in calling rates throughout the day. National standards dictate that surveys should start 30 minutes after dusk, because in most parts of the country, the majority of frogs call during the post-dusk hours. However, here in Alaska dusk surveys may not be possible because the sun sets fairly late in the evening during spring.

Survey Method

Once you arrive on the site, wait to begin your survey for two to three minutes, and remain quiet and still during that time. When you’re ready to begin the survey, make note of the time and simply listen for a three-minute period. You will estimate the approximate number of frogs using the Wisconsin Call Index.

Wood Frog Calling Intensity Index

Index Audio Description
0   No amphibians calling.
1 Listen Individuals can be counted. There is space between calls (approximately 1-6 frogs).
2 Listen Calls of individuals can be distinguished but there is some overlapping of calls (approximately 6-12 frogs).
3 Listen Full chorus. Calls are constant, continuous, and overlapping (more than 12 frogs).
  Listen Training audio

Record your start and stop times, the Wisconsin Call Index value, and estimate the number of frogs you hear calling whenever possible. Be sure to fill in the date, time, observers’ names, site and route numbers, and weather information for every survey.

Please Follow These Instructions When Frog Watching:

  1. Make sure that you have the necessary equipment before arriving at your route:
    • Appropriate data sheets
    • Pencil
    • (Optional) Thermometer and GPS
  2. Remember to keep your distance from the actual site where frogs are calling: This will ensure that the breeding area is left undisturbed, and that your presence won’t frighten the frogs and silence them.
  3. Site Description Form:
    Fill out one Site Description Form for each site you survey, but you only have to do this on the first visit. In the space provided, describe the location of the site and the listening post in enough detail so that anyone else would be able to find it again by reading your directions. If you have access to a GPS, we strongly encourage you to document the latitude, longitude, and elevation of the site. The bottom half of the page is a multiple-choice form for describing the habitat: Simply circle one item in each box unless directed otherwise.
  4. Observation Data Sheet:
    Roadside, backyard, and incidental surveys use the same data form: Be sure to circle at the top of the datasheet the type of survey you are performing.

    Record the observers’ names, the date, and route # (if applicable).

    Record the requested weather information by simply circling the appropriate choices.
    • Air Temperature (present and past 24 hours)
    • Wind Speed (using the Beaufort Wind Scale)
    • Precipitation (present and past 48 hours)
  5. Get Quiet and Comfortable
    Stay quiet for three minutes before starting to listen for frogs – your arrival may have stopped the frogs from calling. Remain as still and quiet as possible during this time so you don’t disturb the frogs – they may stop singing if you make too much noise.
  6. Listen for Frogs
    When you are ready, cup your hands around your ears and listen for precisely 3 minutes.
  7. Record Your Data
    After three minutes, record:
    • The time you started listening
    • The time you stopped
    • The different species you heard (this will most likely only be wood frogs)
    • The calling intensity (using the Wisconsin Calling Index)
    • Whenever possible, estimate the number of frogs you hear calling
    You can start over if you are disturbed – for example, an airplane flies overhead or a car drives past you. Just remember to change the time you started on the data sheet.
  8. Returning Your Data Sheets – Comments and Questions
    Please return all of your completed forms to the Project Coordinator by July 15th of this year. You may submit them electronically via email, by fax, or through the mail. We will send you a self addressed, stamped envelope for this purpose upon request. Please direct comments or questions to:

    Marian Snively
    Alaska Department of Fish and Game
    333 Raspberry Road
    Anchorage, Alaska 99518
    phone: (907) 267-2893
    Fax: (907) 267-2433
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