Polyommatus icarus
In 3 days ~70% in a week ~90%
The common blue butterfly or European common blue (Polyommatus icarus) is a butterfly in the family Lycaenidae and subfamily Polyommatinae. The butterfly is found throughout the Palearctic and has been introduced to North America. Butterflies in the Polyommatinae are collectively called blues, from the coloring of the wings. Common blue males usually have wings that are blue above with a black-brown border and a white fringe. The females are usually brown above with a blue dusting and orange spots.
The Common blue was elected as the national butterfly of Israel in 2023. The contest was launched by the National Butterfly Lovers of Israel Association, with the participation of other nature organizations. A factor in the election result is that like Polyommatus icarus, the flag of Israel is blue and white.
This species was first described by Siegmund Adrian von Rottemburg in 1775. Vernacular names that have been given to P. icarus include little blew argus, blew argus, mixed argus, selvedg'd argus, ultramarine blue, caerulean butterfly, and alexis.
Possible Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Kiskunság National Park | 🇭🇺 Hungary | |
| 2 | Bavarian Forest National Park | 🇩🇪 Germany | |
| 3 | Cévennes National Park | 🇫🇷 France | |
| 4 | Picos de Europa National Park | 🇪🇸 Spain | |
| 5 | Hortobágy National Park | 🇭🇺 Hungary | |
| 6 | Mercantour National Park | 🇫🇷 France | |
| 7 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 8 | Aigüestortes National Park | 🇪🇸 Spain | |
| 9 | Plitvice Lakes National Park | 🇭🇷 Croatia | |
| 10 | Wadden Sea National Park | 🇩🇪 Germany | |
| 11 | Pyrénées National Park | 🇫🇷 France | |
| 12 | Cairngorms National Park | 🇬🇧 United Kingdom | |
| 13 | Biebrza National Park | 🇵🇱 Poland | |
| 14 | Ordesa y Monte Perdido National Park | 🇪🇸 Spain | |
| 15 | Fertő-Hanság National Park | 🇭🇺 Hungary | |
| 16 | Triglav National Park | 🇸🇮 Slovenia | |
| 17 | Camargue | 🇫🇷 France | |
| 18 | Białowieża National Park | 🇵🇱 Poland | |
| 19 | Sierra de Guadarrama National Park | 🇪🇸 Spain | |
| 20 | Ecrins National Park | 🇫🇷 France | |
| 21 | Sierra Nevada National Park | 🇪🇸 Spain |
Possible
About 30% of wildlife watchers report a Common Blue sighting in Hortobágy National Park on a given day, based on 10 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 4th most-seen of the 22 insects we can rate there. Over three days the chance rises to about 70%, and over a week to about 90%, if each day is a fresh chance.
May and September
In those months about 50% of wildlife watchers report a Common Blue in Hortobágy National Park on a given day, against under 5% in March–April, June and October, the lowest months.
Between noon and 3 pm
Across all the parks we cover, that three-hour window holds the most Common Blue sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
5th of 21
Of the 21 parks where we can rate Common Blue sightings, Hortobágy National Park ranks 5th at about 30%. The best odds are in Kiskunság National Park (Hungary, about 40%), Bavarian Forest National Park (Germany, about 30%) and Cévennes National Park (France, about 30%). All parks ranked.
Same family: Lycaenidae
The closest relatives of the Common Blue that you can see in Hortobágy National Park (family Lycaenidae, Gossamer-winged Butterflies) are Large Copper (about 30%), Lesser Fiery Copper (about 30%) and Small Copper (about 30%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Common Blue is recorded against all the insects logged in Hortobágy National Park (10 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
