Ephemera danica
In 3 days ~20% in a week ~40%
Ephemera danica, the green drake or green drake mayfly, is a species of mayfly in the genus Ephemera. Ephemera danica can reach an imago size of 15–20 mm (0.6–0.8 in) in males, while females are larger, reaching 16–25 mm (0.6–1.0 in). This mayfly, with its characteristic markings and three tails (cerci), is the most commonly seen of British Ephemeridae. Imago wings are translucent with dark veining, while in subimago they are dull and yellowish with brown veins. Moreover, forelegs and the tails of the spinners are much longer than in duns. Mouthparts are non-functional, as adults do not feed.
These insects are aeroplankton and usually are food for swallows, trout and various species of amphibians and spiders. The life cycle usually lasts one or two years, but sometimes the developing nymphal forms may last for up to three years. Nymphs can reach a length of about 30 millimetres (1.2 in). They dig tunnels into the gravel in the beds of rivers and feed by filtering organic detritus, before emerging in spring and moving towards shallow waters.
The adults mainly can be found in May–June (hence the common name of mayfly), at the end of many larval stages... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Plitvice Lakes National Park | 🇭🇷 Croatia | |
| 2 | Bavarian Forest National Park | 🇩🇪 Germany | |
| 3 | Pyrénées National Park | 🇫🇷 France |
No species of the same family or order lives in Bavarian Forest National Park, so these are its closest relatives here: other insects.
With luck
About 10% of wildlife watchers report a European Green Drake sighting in Bavarian Forest National Park on a given day, based on 15 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 347th most-seen of the 1115 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
May to August
In those months about 10% of wildlife watchers report a European Green Drake in Bavarian Forest National Park on a given day, against under 5% in September to April, the lowest months.
Between 7 and 10 am
Across all the parks we cover, that three-hour window holds the most European Green Drake sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
2nd of 3
Of the 3 parks where we can rate European Green Drake sightings, Bavarian Forest National Park ranks 2nd at about 10%. The best odds are in Plitvice Lakes National Park (Croatia, about 20%).
GBIF citizen-science records
It is estimated from how often the European Green Drake is recorded against all the insects logged in Bavarian Forest National Park (15 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.
