Hydrometra stagnorum
In 3 days ~10% in a week ~30%
Hydrometra stagnorum, the common water-measurer, is a species of aquatic bugs in the family Hydrometridae, the water measurers. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cévennes National Park | 🇫🇷 France | |
| 2 | Sierra Nevada National Park | 🇪🇸 Spain | |
| 3 | Pyrénées National Park | 🇫🇷 France | |
| 4 | Wadden Sea National Park | 🇩🇪 Germany |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Paris | 🇫🇷 France | |
| 2 | Porto | 🇵🇹 Portugal | |
| 3 | Berlin | 🇩🇪 Germany | |
| 4 | Hamburg | 🇩🇪 Germany | |
| 5 | Munich | 🇩🇪 Germany | |
| 6 | London | 🇬🇧 United Kingdom | |
| 7 | Essen | 🇩🇪 Germany | |
| 8 | Birmingham | 🇬🇧 United Kingdom | |
| 9 | Warsaw | 🇵🇱 Poland | |
| 10 | Copenhagen | 🇩🇰 Denmark |
Rare
Under 5% of wildlife watchers report a Common Water Measurer sighting in London on a given day, based on 32 verified sightings from GBIF citizen-science data. It is the 629th most-seen of the 1504 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.
April
In that month about 10% of wildlife watchers report a Common Water Measurer in London on a given day, against under 5% in May to March, the lowest months.
Between 2 and 5 pm
Across all the parks we cover, that three-hour window holds the most Common Water Measurer sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
6th of 12
Of the 12 cities where we can rate Common Water Measurer sightings, London ranks 6th at under 5%. The best odds are in Paris (France, about 10%), Porto (Portugal, under 5%) and Berlin (Germany, under 5%).
Same order: Hemiptera
The closest relatives of the Common Water Measurer that you can see in London (order Hemiptera, True Bugs, Hoppers, Aphids, and allies) are Green Shield Bug (about 30%), Trivial Plant Bug (about 30%) and Dock Bug (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Common Water Measurer is recorded against all the insects logged in London (32 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.
