Data Collection Faq

Frequently Asked Questions

When should I start collecting firefly data?

The simple answer is just before firefly season starts in your area. If you start observing before fireflies are expected to emerge, then you will be sure to record when they first appear in your habitat. To get a sense of when firefly season begins in your area, check out the first and last sightings chart and map (PDF). Although not completely accurate, the map offers a good indication of when you might see your first firefly of the season. As we collect more data each year, this emergence information will become more accurate.

If I don't have any fireflies in my backyard, should I still report this all summer?

Yes! Please report once a week even if you don't see any fireflies. This is important for two reasons:

  1. It may be that you don't have any species of fireflies active early in the summer, but you will have fireflies that will emerge later in the season. This is valuable information to the firefly researchers.
  2. Researchers want to know what affects the populations of fireflies. Why are they common in one area and absent in another? By looking at the data from the habitat sheets for areas with no fireflies, researchers might be able to begin to understand some of these factors. That is why reporting no fireflies is just as important as reporting many fireflies.

Collecting data for areas with no fireflies should only take a minute. Walk out into your backyard, look around for 10 seconds to make sure there are no fireflies present, and note the time, clouds, wind, and temperature.

If I don't have any fireflies in my backyard, can I choose another site that does have fireflies?

Yes! Of course it is a lot more fun to monitor a site with fireflies than one without, so feel free to pick a second site. If you can, pick a site close to your home, because it will be easier to get to on a weekly basis. Make sure that you have permission to visit the site. A public site like a school yard or other town property is a good place to choose.

If you do choose a second site, please remember to send in data for your backyard site as well. That information is very important to us.

Is it OK if I can't collect data every week during firefly season?

Yes!  Of course, the more data you can collect, the better, but we appreciate any data you can send us.  Even if you can only collect data for a few weeks during the summer, it will be of value to us.

What is the best time for observing fireflies and collecting data?

Different types of fireflies are active at different times during the night and different times throughout the summer. Some fireflies begin flashing shortly after dusk and are active for only about an hour, while others are active until midnight. One of our early risers reports seeing fireflies at 4:00 a.m.

Typically, Pyractomena fireflies emerge in late May or early June; Photinus appear a little later.

For the purposes of our study, it doesn't matter when you observe and record. In fact, it might be fun to observe at different times of the evening and see if you can notice a difference in the fireflies you see.

It's early spring and I'm seeing daytime fireflies Should I count them and enter them as data for my habitat?

No. Daytime fireflies are not part of this project. You should only be counting the fireflies that you see flashing. This is especially important in helping us determine when fireflies become active in state. Some daytime fireflies appear much earlier in the season than flashing fireflies, and entering data for them would skew our emergence data.

I see larval fireflies glowing in my yard. Should I be counting and recording them?

No. As with the daytime fireflies, this project does not include larvae counts. However, that may make an interesting project for the future.

I am having a difficult time determining the color of the fireflies I am seeing. Do you have any tips?

Do the best you can and don't worry too much if you are not sure. Distinguishing the different color flashes is sometimes very difficult, especially if it is not completely dark. Also, distance and moisture in the air can affect the color you see. Record your best guess, and you will become better at it with time and practice.


Volunteer to share your observations of fireflies in your backyard — no special scientific training required.
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We've made our full data set available online, and you're invited to interpret it.
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Pick a location, observe it weekly, and use our online tools to follow your progress.
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Be on the lookout for fireflies that flash while flying in a "J" shape. Identifying them can help one of our researchers!

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