Acroneuria abnormis
In 3 days ~10% in a week ~20%
Acroneuria abnormis, the common stone, is a species of common stonefly in the family Perlidae. It is found in North America. During mating, pairs engage in drumming behavior that can be used to identify species. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Shenandoah National Park | 🇺🇸 United States | |
| 2 | Great Smoky Mountains National Park | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Common Stone sighting in Great Smoky Mountains National Park on a given day, based on 5 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 628th most-seen of the 822 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.
October and November
In those months about 10% of wildlife watchers report a Common Stone in Great Smoky Mountains National Park on a given day, against under 5% in December to September, the lowest months.
Between noon and 3 pm
Across all the parks we cover, that three-hour window holds the most Common Stone sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
2nd of 2
Of the 2 parks where we can rate Common Stone sightings, Great Smoky Mountains National Park ranks 2nd at under 5%. The best odds are in Shenandoah National Park (United States, about 10%).
GBIF citizen-science records
It is estimated from how often the Common Stone is recorded against all the insects logged in Great Smoky Mountains National Park (5 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.
