Lethe eurydice
In 3 days ~20% in a week ~40%
Lethe eurydice, the eyed brown or marsh eyed brown, is a species of Satyrinae butterfly that is native to North America. Wingspan: 38 to 48 mm. They have one brood with a flight period from late June through August. Larvae feed on sedges (Carex) in particular C. lacustris, C. atherodes, C. rostrata, and C. stricta. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Congaree National Park | 🇺🇸 United States | |
| 2 | Acadia National Park | 🇺🇸 United States | |
| 3 | Great Smoky Mountains National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Washington | 🇺🇸 United States | |
| 2 | Chicago | 🇺🇸 United States | |
| 3 | Toronto | 🇨🇦 Canada | |
| 4 | New York City | 🇺🇸 United States | |
| 5 | Montreal | 🇨🇦 Canada | |
| 6 | Boston | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report an Eyed Brown sighting in Acadia National Park on a given day, based on 14 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 171st most-seen of the 405 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.
June and July
In those months about 10% of wildlife watchers report an Eyed Brown in Acadia National Park on a given day, against under 5% in August to May, the lowest months.
Between 10 am and 1 pm
Across all the parks we cover, that three-hour window holds the most Eyed Brown sightings with a recorded time, and nearly all 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 Eyed Brown sightings, Acadia National Park ranks 2nd at about 10%. The best odds are in Congaree National Park (United States, about 20%).
GBIF citizen-science records
It is estimated from how often the Eyed Brown is recorded against all the insects logged in Acadia National Park (14 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.
