Aquarius najas
In 3 days ~50% in a week ~80%
Aquarius najas, also known as the river skater, is a European species of water strider. It was formerly known as Gerris najas, but the subgenus Aquarius was elevated to generic rank in 1990 on the basis of phylogenetic analysis.
This species generally require moving waters, living in places like the stony margins of rivers. Aquarius najas is among the largest species of water striders, as typical of members of the genus Aquarius (including another European species, the on average marginally smaller A. paludum). Adult females of A. najas average 16.5 mm (0.65 in) long and males about 30% smaller. In northern Europe it is wingless, but in central and southern Europe it often has wings.
Aquarius najas spend the winter as adults. In the spring, they form pairs, and before mating, row about together on the surface during the daytime. At night, they separate, and the females lay their eggs beneath the water in closely packed patches. Normally the eggs are laid on the surface of flat stones. Males may guard females after copulation to prevent other males from competing. It has been claimed that males may remain paired with females for several... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Plitvice Lakes National Park | 🇭🇷 Croatia | |
| 2 | Cévennes National Park | 🇫🇷 France | |
| 3 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 4 | Pyrénées National Park | 🇫🇷 France |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Birmingham | 🇬🇧 United Kingdom |
Possible
About 20% of wildlife watchers report a River Skater 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.
April
In that month about 50% of wildlife watchers report a River Skater in Plitvice Lakes National Park on a given day, against under 5% in March and September–October, the lowest months. December has too few records to rate.
Between 3 and 6 pm
Across all the parks we cover, that three-hour window holds the most River Skater sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Yes
Of the 4 parks where we can rate River Skater sightings, Plitvice Lakes National Park has the highest daily chance: about 20%. Next come Cévennes National Park (France, about 10%) and Snowdonia National Park (United Kingdom, about 10%).
Same order: Hemiptera
The closest relatives of the River Skater that you can see in Plitvice Lakes National Park (order Hemiptera, True Bugs, Hoppers, Aphids, and allies) are European Striped Shield Bug (about 30%), European Firebug (about 20%) and Forest Bug (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the River Skater 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.
