Butterfly survey 2025 - FAQs
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What will be done with your observations?
The Agroecology-Transect project brings together the knowledge and expertise of farmers, scientists, policy-makers and NGOs from all over Europe.
We will analyze the butterfly data to understand how agroecological farming practices shape agricultural ecosystems, and to inform and adapt biodiversity conservation measures across Europe.
Frequently asked questions
FAQs about butterflies
Do butterflies live only one day as adults?
No! Depending on species, the adults may live a few days (e.g. 1–2 weeks), a few weeks (e.g. 2–3 weeks for various Whites) or several months – especially when the species overwinters as an adult – such as Admiral or Pickock, in which case they can live 7–8 months or even a full year (Brimstone)!
Why are butterflies such good ecological indicators?
The number and variety of butterflies can tell us a lot about the health of an ecosystem. Their short life cycles allow them to react quickly to environmental changes. Their larvae often specialise on specific food plants and habitats, and many species fly a limited distance – making them highly sensitive to climate and the local environment. Since they are easy to observe and count, they help us measure ecosystem health: when butterflies are disappearing it’s an early warning sign for many other groups too; but when we take the right measures, we can see a positive response.
FAQs on selecting a site
How do I select a site?
Select a site where you can comfortably walk around for over 15 minutes, and ideally one that you plan to revisit a few times during spring/summer. It could be your own field, a pasture, public space or private land – in which case, please make sure you have explicit permission for counting butterflies.
The goal in Agroecology-TRANSECT is to survey butterflies both within fields and at the edge of fields, where spontaneous vegetation or sometimes sown flower strips are growing. That’s why it would be optimal if you select a pair of sites: one on the edge and one within the field. A site on the edge should optimally divide half-half between the edge and the field, two fields, or two adjacent habitats (e.g. half on grassland, half on the field).
How often should I visit a site?
Different butterflies are active during different times of year, and some have a shorter flying season (1–2 months only). We advise you to come back at least 3 times to get a good picture of the species in your area.
However, more is better! Some people come every week, but every 2–3 weeks during peak flying season (June–August) would be enough to make sure you don’t miss any species.
FAQs on carrying out a survey
I don’t know the species – can I still count?
YES! The program is designed for anyone who wants to get to know the species in your region. You can start by registering “unidentified white” or “unidentified blue”, and later on you’ll see that you get to know the difference between a small cabbage white and a green-veined white. If you ensure to report on all butterflies you see, we can also see your learning curve. And if you send pictures around, everyone can get to learn with you!
What is the “training mode”?
Activating the training mode (in the app, or in your profile on the eBMS website) means that your data will not be shared with other users and visible on the website. Use this when you are still trying out the app and the method, but remember to switch it off when you start observing, so that your observations contribute to our shared knowledge of current butterfly biodiversity!
Can I pause the 15-min survey to identify a species?
Yes! You can hit the pause button on the app anytime you need to, for instance to take the time to take a picture or identify a butterfly, or to fill out information about the site – or when the weather conditions alter. But remember to hit “play” again once you are ready to look up and continue counting. If you are two people, it is also easier to have one person counting and the other identifying, for instance.
How do I make sure I do not count the same butterfly twice?
The best way to avoid counting the same butterfly twice is by counting only the maximum number of individuals of a species that you can see at the same time during the 15 minutes. Maybe at first you look around and see 1 individual, then 2, then later 1, then again 2… In this case, we ask that you record only 2 butterflies of one species, unless you are relatively sure that you could see new individuals coming in and out of your survey area.
Troubleshooting
How do I mark a site when registering it?
Site registration allows you to name a site and find it again when you return later. It is only possible once you have joined a project, such as the Agroecology-TRANSECT project of your region. When you start an observation and have assigned it to a project, click on “area” and select the tab for “project locations”. There should be a list of nearby existing locations in the project from you and other participants. Click on “add” to name a new site. Your GPS location will be saved automatically while you do the survey.
You can also draw the outline of your site on the map: turn off the GPS toggle, click on the pencil icon to edit, erase the existing GPS point (red bin icon), and use the polygon tool to draw the perimeter of your survey area.
I did not manage to identify all of the butterflies, can I do it later?
YES! Once the survey is over, and before you upload it to the database, you have all the time you need to go back to your pictures and notes, to ask someone for help or consult other resources. After uploading the survey, you can still edit your observations in My Data/my samples on the eBMS website. Tip: the more pictures you take, from both upper and under side, the easier it is for others to help and learn with you.
Why do I need to type the species’ name in the App?
The app requires you to write the species' name, in order to verify that you have to tried your best to identify them yourself, and not just guess based on pictures (which is a good way of getting things wrong). You can take a butterfly book with you, use guidance from online material, a butterfly identification app, or take a picture and share with experts and friends later.
Learn more
How do I get to know the species?
Learning comes with doing it! We recommend using regional field guides for butterflies while in the field, but also importantly taking pictures for later verification. Wait for the butterflies to land on a plant and approach slowly to snap a picture. If you know some butterfly experts or butterfly walks happening around you, this is a great way to gain some field experience. Phone apps can help for identification, and we recommend choosing ones with a good track record – based on community feedback (e.g. iNaturalist).
How can I take pictures and share with others?
You don’t need to catch a butterfly, or have fancy equipment to take a good butterfly picture. Wait for the butterflies to land on a plant and approach slowly to snap a picture, even with your phone. Photos can be shared via community naturalist apps to check identification and connect to your local community of butterfly lovers. Wear green, move slowly and take care of your shadow – and you’ll find out you can come quite close!
Where can I find which species I have in my region?
You can explore existing data collected by users of the butterfly count app all over Europe on the online portal and select your region! The butterfly app already suggests regional species lists at the country level.
What will be done with my observations?
We need your data for analysing which species occur where, how many individuals of each, and how different land management and climatic variables affect them.
To do so we will check and validate the data, and may come back to you with questions e.g. in autumn or later. We intend to use the data for analysing the impacts of various agricultural practices on biodiversity – especially if we know more about the site. Note: if you forget to register your site, it would be hard for us to find and to access your data, and to analyse them effectively. That’s why site registration is important!
Find out more
Butterfly Survey - get involved
Download 'How To' guides (in English, Deutsch, Français, српски)
Butterfly surveys in your region or country