Agrotis bigramma
In 3 days ~10% in a week ~30%
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 |
With luck
About 10% of wildlife watchers report a Great Dart sighting in Porto on a given day, based on 20 verified sightings from GBIF citizen-science data. It is the 255th most-seen of the 498 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.
August and September
In those months about 10% of wildlife watchers report a Great Dart in Porto on a given day, against under 5% in October to July, the lowest months. Those are among Porto's driest months, with about 35 mm of rain a month against 140 mm in January.
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.
Among the best
Of the 4 cities where we can rate Great Dart sightings, Porto ranks 2nd at about 10%, level with the leaders once rounded. The best odds are in Budapest (Hungary, about 10%).
Same genus: Agrotis
The closest relatives of the Great Dart that you can see in Porto (genus Agrotis) are Turnip Moth (about 10%), Ipsilon Dart Moth (about 10%) and Heart And Dart (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Great Dart is recorded against all the insects logged in Porto (20 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.
