Speyeria egleis
In 3 days ~20% in a week ~40%
Speyeria egleis, commonly known as the Great Basin fritillary or egleis fritillary, is a butterfly of the family Nymphalidae. It is found in the United States, where it has been recorded from North Dakota southwest through Oregon to California and south to Colorado. The habitat consists of mountain meadows, forest openings and exposed rocky ridges.
The wingspan is 45–60 mm. The wings are bright to dull orange brown with dark markings. Adults are on wing from late June to August. The larvae feed on the leaves of Viola species, including V. adunca, V. nuttallii, V. purpurea, and V. walteri. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Sequoia and Kings Canyon National Parks | 🇺🇸 United States | |
| 2 | Yosemite National Park | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Great Basin Fritillary sighting in Yosemite National Park on a given day, based on 12 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 109th most-seen of the 227 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.
July to September
In those months about 10% of wildlife watchers report a Great Basin Fritillary in Yosemite National Park on a given day, against under 5% in October to June, the lowest months. Those are among Yosemite National Park's driest months, with about 25 mm of rain a month against 220 mm in January.
Between noon and 3 pm
Across all the parks we cover, that three-hour window holds the most Great Basin Fritillary sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
Among the best
Of the 2 parks where we can rate Great Basin Fritillary sightings, Yosemite National Park ranks 2nd at about 10%, level with the leaders once rounded. The best odds are in Sequoia and Kings Canyon National Parks (United States, about 10%).
Same genus: Speyeria
The closest relatives of the Great Basin Fritillary that you can see in Yosemite National Park (genus Speyeria) are Mormon Fritillary (about 20%), Hydaspe Fritillary (about 10%) and Great Spangled Fritillary (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Great Basin Fritillary is recorded against all the insects logged in Yosemite National Park (12 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.
