Lysandra coridon
In 3 days ~10% in a week ~30%
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 |
Rare
Under 5% of wildlife watchers report a Chalkhill Blue sighting in Cévennes National Park on a given day, based on 8 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 730th most-seen of the 996 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
July and August
In those months about 10% of wildlife watchers report a Chalkhill Blue in Cévennes National Park on a given day, against under 5% in September to June, the lowest months. Those are among Cévennes National Park's driest months, with about 45 mm of rain a month against 260 mm in October.
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.
11th of 11
Of the 11 parks where we can rate Chalkhill Blue sightings, Cévennes National Park ranks 11th at under 5%. The best odds are in Triglav National Park (Slovenia, about 40%), Vanoise National Park (France, about 40%) and Aigüestortes National Park (Spain, about 40%).
Same genus: Lysandra
The closest relatives of the Chalkhill Blue that you can see in Cévennes National Park (genus Lysandra) are Adonis Blue (about 20%) and Provence Chalk-Hill Blue (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Chalkhill Blue is recorded against all the insects logged in Cévennes National Park (8 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.
