Lysandra coridon
In 3 days ~70% in a week ~90%
The chalkhill blue (Lysandra coridon) is a butterfly in the family Lycaenidae. It is a small butterfly that can be found throughout the Palearctic realm, where it occurs primarily in grasslands rich in chalk. Males have a pale blue colour, while females are brown. Both have chequered fringes around their wings.
As with many blue butterflies, separation from similar species in the field is on the underside markings... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Triglav National Park | 🇸🇮 Slovenia | |
| 2 | Vanoise National Park | 🇫🇷 France | |
| 3 | Aigüestortes National Park | 🇪🇸 Spain | |
| 4 | Mercantour National Park | 🇫🇷 France | |
| 5 | Picos de Europa National Park | 🇪🇸 Spain | |
| 6 | Ordesa y Monte Perdido National Park | 🇪🇸 Spain | |
| 7 | Ecrins National Park | 🇫🇷 France | |
| 8 | Pyrénées National Park | 🇫🇷 France | |
| 9 | Hohe Tauern National Park | 🇦🇹 Austria | |
| 10 | Bavarian Forest National Park | 🇩🇪 Germany | |
| 11 | Cévennes National Park | 🇫🇷 France |
Possible
About 30% of wildlife watchers report a Chalkhill Blue sighting in Ecrins National Park on a given day, based on 74 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 7th most-seen of the 251 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.
August
In that month about 40% of wildlife watchers report a Chalkhill Blue in Ecrins National Park on a given day, against under 5% in February, 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 Chalkhill 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.
7th of 11
Of the 11 parks where we can rate Chalkhill Blue sightings, Ecrins National Park ranks 7th at about 30%. The best odds are in Triglav National Park (Slovenia, about 40%), Vanoise National Park (France, about 40%) and Aigüestortes National Park (Spain, about 40%).
GBIF citizen-science records
It is estimated from how often the Chalkhill Blue is recorded against all the insects logged in Ecrins National Park (74 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.
