Arethusana arethusa
In 3 days ~10% in a week ~20%
Arethusana is a butterfly genus from the subfamily Satyrinae of the brush-footed butterfly family (Nymphalidae). It is composed of only one species, Arethusana arethusa, the false grayling. Arethusana arethusa dentata (Staudinger, 1871) (Catalonia – Spain) The subspecies Arethusana arethusa boabdil and Arethusana arethusa dentata are considered as full species by some authors. Arethusana arethusa has a wingspan of 42–47 millimetres (1.7–1.9 in) in males, of 50–54 millimetres (2.0–2.1 in) in females. The length of the forewings can reach 21–25 mm. The upper surface of the wings is dark brown, with a characteristic series of ocher-orange oval markings forming a V and a blackish brown large spot close to the top of the forewings. Also the hindwings have a small blackish spot near the... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cévennes National Park | 🇫🇷 France | |
| 2 | Mercantour National Park | 🇫🇷 France | |
| 3 | Pyrénées National Park | 🇫🇷 France |
Rare
Under 5% of wildlife watchers report a False Grayling sighting in Pyrénées National Park on a given day, based on 8 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 1144th most-seen of the 1277 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.
August and September
In those months about 10% of wildlife watchers report a False Grayling in Pyrénées National Park on a given day, against under 5% in October to July, the lowest months.
Between 10 am and 1 pm
Across all the parks we cover, that three-hour window holds the most False Grayling sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
3rd of 3
Of the 3 parks where we can rate False Grayling sightings, Pyrénées National Park ranks 3rd at under 5%. The best odds are in Cévennes National Park (France, about 10%) and Mercantour National Park (France, about 10%).
GBIF citizen-science records
It is estimated from how often the False Grayling is recorded against all the insects logged in Pyrénées 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.
