Glaucopsyche alexis
In 3 days ~10% in a week ~30%
Glaucopsyche alexis, the green-underside blue, is a butterfly of the family Lycaenidae. It is found in the Palearctic. The butterfly flies from April to July depending on the location, lingering in warm, lush meadows with plenty of its host plant, vetch (Vicia).
Male above light cyaneous blue with a violet sheen and narrow black border; female darker blue with the black border gradually shading off, so that it occupies nearly the whole outer half of the wings. Beneath silver-grey (male) or ashy grey (female), the forewing with 5 or 6 large rounded black spots, the hindwing with small ocelli and in its whole basal half with metallic blue-green dusting. In ab. dimus Bgstr. the ocelli of the forewing beneath are reduced to 4; on the other hand, they may also be increased in number, or may be elongate (= subtus-radiata Oberth.). In European Turkey and the neighbouring districts of Anterior Asia the ocelli of... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Mercantour National Park | 🇫🇷 France | |
| 2 | Cévennes National Park | 🇫🇷 France | |
| 3 | Pyrénées National Park | 🇫🇷 France | |
| 4 | Sierra de Guadarrama National Park | 🇪🇸 Spain | |
| 5 | Bavarian Forest National Park | 🇩🇪 Germany |
Rare
Under 5% of wildlife watchers report a Green-Underside Blue sighting in Bavarian Forest National Park on a given day, based on 5 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 964th most-seen of the 1115 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.
May and June
In those months about 10% of wildlife watchers report a Green-Underside Blue in Bavarian Forest National Park on a given day, against under 5% in July to April, the lowest months.
Between 10 am and 1 pm
Across all the parks we cover, that three-hour window holds the most Green-Underside 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 5
Of the 5 parks where we can rate Green-Underside Blue sightings, Bavarian Forest National Park ranks 5th at under 5%. The best odds are in Mercantour National Park (France, about 10%), Cévennes National Park (France, about 10%) and Pyrénées National Park (France, about 10%).
Same family: Lycaenidae
The closest relatives of the Green-Underside Blue that you can see in Bavarian Forest National Park (family Lycaenidae, Gossamer-winged Butterflies) are Common Blue (about 30%), Small Copper (about 20%) and Holly Blue (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Green-Underside Blue is recorded against all the insects logged in Bavarian Forest National Park (5 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.
