Agrotis bigramma
In 3 days ~10% in a week ~20%
Agrotis bigramma, the great dart, is a moth of the family Noctuidae. The species was first described by Eugenius Johann Christoph Esper in 1790. It occurs in Europe, North Africa, and Asia east to Afganistan and SW Siberia; it is widespread in much of Europe but scarce or absent in the northern parts (it is a rare visitor Great Britain).
The wingspan is 40–48 mm. Adults are on wing from July to December (primarily August in the UK, September to November in the south). There is one generation per year. The larvae are polyphagous and are found on the roots and lower parts of various low-growing herbaceous plants including Poaceae and Scrophulariaceae. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Sierra de Guadarrama National Park | 🇪🇸 Spain | |
| 2 | Pyrénées National Park | 🇫🇷 France |
Rare
Under 5% of wildlife watchers report a Great Dart sighting in Vienna on a given day, based on 8 verified sightings from GBIF citizen-science data. It is the 1090th most-seen of the 1406 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
In that month about 10% of wildlife watchers report a Great Dart in Vienna on a given day, against under 5% in September to July, the lowest months. That is one of Vienna's wettest months, with about 85 mm of rain against 40 mm in February.
Between 10 pm and 1 am
Across all the parks we cover, that three-hour window holds the most Great Dart sightings with a recorded time, and about 8 in 10 of them come between 6 pm and 6 am: it is mostly seen at night.
4th of 4
Of the 4 cities where we can rate Great Dart sightings, Vienna ranks 4th at under 5%. The best odds are in Budapest (Hungary, about 10%), Porto (Portugal, about 10%) and Berlin (Germany, under 5%).
GBIF citizen-science records
It is estimated from how often the Great Dart is recorded against all the insects logged in Vienna (8 verified sightings), 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.
