Ephemera danica
In 3 days ~50% in a week ~80%
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 Plitvice Lakes National Park, so these are its closest relatives here: other insects.
Possible
About 20% of wildlife watchers report a European Green Drake sighting in Plitvice Lakes National Park on a given day, based on 7 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 28th most-seen of the 51 insects we can rate there. Over three days the chance rises to about 50%, and over a week to about 80%, if each day is a fresh chance.
May and June
In those months about 40% of wildlife watchers report a European Green Drake in Plitvice Lakes National Park on a given day, against under 5% in March–April, July and September–October, the lowest months. December has too few records to rate.
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.
Yes
Of the 3 parks where we can rate European Green Drake sightings, Plitvice Lakes National Park has the highest daily chance: about 20%. Next come Bavarian Forest National Park (Germany, about 10%) and Pyrénées National Park (France, under 5%).
GBIF citizen-science records
It is estimated from how often the European Green Drake is recorded against all the insects logged in Plitvice Lakes National Park (7 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.
