Tachina grossa
In 3 days ~20% in a week ~30%
Tachina grossa is a very large tachinid fly. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cairngorms National Park | 🇬🇧 United Kingdom | |
| 2 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 3 | Cévennes National Park | 🇫🇷 France | |
| 4 | Pyrénées National Park | 🇫🇷 France | |
| 5 | Wadden Sea National Park | 🇩🇪 Germany |
With luck
About 10% of wildlife watchers report a Yellow-Faced Fly sighting in Cévennes National Park on a given day, based on 9 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 619th most-seen of the 996 insects we can rate there. Over three days the chance rises to about 20%, 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 Yellow-Faced Fly 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 Yellow-Faced Fly sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Among the best
Of the 5 parks where we can rate Yellow-Faced Fly sightings, Cévennes National Park ranks 3rd at about 10%, level with the leaders once rounded. The best odds are in Cairngorms National Park (United Kingdom, about 10%) and Snowdonia National Park (United Kingdom, about 10%).
Same family: Tachinidae
The closest relatives of the Yellow-Faced Fly that you can see in Cévennes National Park (family Tachinidae, Tachinid Flies) are Ectophasia crassipennis (about 10%) and Cylindromyia bicolor (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Yellow-Faced Fly is recorded against all the insects logged in Cévennes National Park (9 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.
