Lethe anthedon
In 3 days ~20% in a week ~30%
Lethe anthedon, the northern pearly-eye, is a species of butterfly in the subfamily Satyrinae of the family Nymphalidae. It is found in North America, from central Saskatchewan and eastern Nebraska east to Nova Scotia, south to central Alabama and Mississippi.
The wingspan is 1 1/2 to 2 1/2 inches (43–67 mm.) The upperside is brown with dark eyespots and the underside is brown. Adults feed on dung, fungi, carrion and sap from willows, poplars, and birches. The larvae feed on various grasses, including Leersia virginica, Erianthus species, Muhlenbergia species, bearded shortgrass (Brachyelytrum erectum), Chasmanthium latifolium, bottlebrush grass (Hystrix patula), and false melic grass (Schizachne purpurascens). The host plants of a northern population include sedges (Carex species).
The species overwinters in the larval stage. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Elk Island National Park | 🇨🇦 Canada | |
| 2 | Riding Mountain National Park | 🇨🇦 Canada | |
| 3 | Isle Royale National Park | 🇺🇸 United States | |
| 4 | Shenandoah National Park | 🇺🇸 United States | |
| 5 | Acadia National Park | 🇺🇸 United States | |
| 6 | Great Smoky Mountains National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Washington | 🇺🇸 United States | |
| 2 | Edmonton | 🇨🇦 Canada | |
| 3 | Chicago | 🇺🇸 United States | |
| 4 | Baltimore | 🇺🇸 United States | |
| 5 | Toronto | 🇨🇦 Canada | |
| 6 | Minneapolis [Saint Paul] | 🇺🇸 United States | |
| 7 | Montreal | 🇨🇦 Canada |
With luck
About 10% of wildlife watchers report a Northern Pearly-Eye sighting in Washington on a given day, based on 173 verified sightings from GBIF citizen-science data. It is the 180th most-seen of the 1807 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 30%, if each day is a fresh chance.
June and August–September
In those months about 10% of wildlife watchers report a Northern Pearly-Eye in Washington on a given day, against under 5% in July and October–May, the lowest months.
Between 10 am and 1 pm
Across all the parks we cover, that three-hour window holds the most Northern Pearly-Eye 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 7 cities where we can rate Northern Pearly-Eye sightings, Washington has the highest daily chance: about 10%. Next come Edmonton (Canada, about 10%) and Chicago (United States, under 5%).
GBIF citizen-science records
It is estimated from how often the Northern Pearly-Eye is recorded against all the insects logged in Washington (173 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.
