Polyommatus eros
In 3 days ~60% in a week ~90%
Polyommatus eros, the Eros blue or common meadow blue, is a species of blue butterfly found in the Palearctic. L. eros O. (= tithonus Hbn.) (80 c, d). male very bright blue, with a metallic gloss like enamel, black margin to the forewing and black distal-marginal spots to the hindwing, these spots contrasting strongly with the pure white fringes. Female brown, sometimes with yellowish red distal-marginal spots. Underside strongly recalling icarus, but male as well as female with distinct white median streak on the hindwing. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Hohe Tauern National Park | 🇦🇹 Austria | |
| 2 | Vanoise National Park | 🇫🇷 France | |
| 3 | Mercantour National Park | 🇫🇷 France | |
| 4 | Ecrins National Park | 🇫🇷 France | |
| 5 | Pyrénées National Park | 🇫🇷 France |
Possible
About 20% of wildlife watchers report an Eros Blue sighting in Mercantour National Park on a given day, based on 32 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 71st most-seen of the 412 insects we can rate there. Over three days the chance rises to about 60%, and over a week to about 90%, if each day is a fresh chance.
July
In that month about 40% of wildlife watchers report an Eros Blue in Mercantour National Park on a given day, against under 5% in September to May, the lowest months.
Between 10 am and 1 pm
Across all the parks we cover, that three-hour window holds the most Eros Blue sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
3rd of 5
Of the 5 parks where we can rate Eros Blue sightings, Mercantour National Park ranks 3rd at about 20%. The best odds are in Hohe Tauern National Park (Austria, about 30%) and Vanoise National Park (France, about 30%).
GBIF citizen-science records
It is estimated from how often the Eros Blue is recorded against all the insects logged in Mercantour National Park (32 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.
